Micro Station V8i Everything 3D

TRN012880-1/0001

MicroStation V8i Everything 3D

Bentley Institute Course Guide

Trademarks

AccuDraw, Bentley, the “B” Bentley logo, MDL, MicroStation and SmartLine are registered trademarks; PopSet and Raster Manager are trademarks; Bentley SELECT is a service mark of Bentley Systems, Incorporated or Bentley Software, Inc.

Java and all Java‐based trademarks and logos are trademarks or registered trademarks of Sun Microsystems, Inc. in the U.S. and other countries.

Adobe, the Adobe logo, Acrobat, the Acrobat logo, Distiller, Exchange, and PostScript are trademarks of Adobe Systems Incorporated.

Windows, Microsoft and Visual Basic are registered trademarks of Microsoft Corporation.

AutoCAD is a registered trademark of Autodesk, Inc.

Other brands and product names are the trademarks of their respective owners.

Patents

United States Patent Nos. 5,8.15,415 and 5,784,068 and 6,199,125.

Copyrights

©2000‐2009 Bentley Systems, Incorporated. MicroStation ©1998 Bentley Systems, Incorporated. IGDS file formats ©1981‐1988 Intergraph Corporation. Intergraph Raster File Formats ©1993 Intergraph Corporation. Portions ©1992 – 1994 Summit Software Company. Portions ©1992 – 1997 Spotlight Graphics, Inc. Portions ©1993 – 1995 Criterion Software Ltd. and its licensors. Portions ©1992 – 1998 Sun MicroSystems, Inc. Portions ©Unigraphics Solutions, Inc. Icc ©1991 – 1995 by AT&T, Christopher W. Fraser, and David R. Hanson. All rights reserved. Portions ©1997 – 1999 HMR, Inc. All rights reserved. Portions ©1992 – 1997 STEP Tools, Inc. Sentry Spelling‐Checker Engine ©1993 Wintertree Software Inc. Unpublished – rights reserved under the copyright laws of the United States and other countries. All rights reserved.

MicroStation V8i Everything 3D ii Feb-09Copyright © 2009 Bentley Systems, Incorporated

Feb-09

Table of Contents

Course Overview ____________________________________ 1Course Description ____________________________________1Target Audience_______________________________________1Prerequisites _________________________________________1Course Objectives _____________________________________2Modules Included _____________________________________2Introductory Knowledge ________________________________3

Questions ________________________________________3Answers__________________________________________4

3D View Control ____________________________________ 5Module Overview _____________________________________5Module Prerequisites __________________________________5Module Objectives_____________________________________5Introductory Knowledge ________________________________6

Questions ________________________________________6Answers__________________________________________6

View Rotation ________________________________________6The Rotate View tool _______________________________7Rotating to a standard view __________________________10Rotating a view using the mouse ______________________11

Fitting 3D Views_______________________________________13Clip Volume __________________________________________13

Clip Volume Options ________________________________16Clip Volume By Section Plane _________________________17Clip Volumes and View Attributes _____________________19Clip Volume Settings and Display Style__________________20Applying a clip volume ______________________________21Manipulating a clip volume from a second view __________28Saving clip volumes_________________________________29Working with multiple clip volumes____________________31Using a clip mask___________________________________34

Display Styles Dialog ___________________________________36Understanding Display Style dialog tools. _______________37

Perspective __________________________________________39Saved Views dialog ____________________________________39

iii Table of ContentsCopyright © 2009 Bentley Systems, Incorporated

Table of Contents

Understanding the Saved Views dialog. _________________40Module Review _______________________________________44

Questions_________________________________________44Answers __________________________________________44

AccuDraw in 3D _____________________________________47Module Overview______________________________________47Module Prerequisites___________________________________47Module Objectives_____________________________________47Introductory Knowledge ________________________________48


The AccuDraw Drawing Plane ____________________________493D Element Placement _________________________________49

Using AccuDraw’s rotated drawing plane________________56Non‐orthogonal rotation_____________________________58Locating elements relative to others ___________________66Using Auxiliary Coordinate Tools ______________________71Auxiliary Coordinates dialog tool features:_______________71AccuDraw Shortcuts for ACS __________________________72Define an ACS aligned with a reference file ______________74ACS interaction with AccuDraw _______________________74Separate ACS per View ______________________________75Projecting Points from and ACS to a Plane _______________75

Module Review _______________________________________76Questions_________________________________________76Answers __________________________________________77

B‐Spline Curves _____________________________________79Module Overview______________________________________79Module Prerequisites___________________________________79Module Objectives_____________________________________79Introductory Knowledge ________________________________80


3D Workflows_________________________________________80Interactive handles to control 3D objects during creation___81

MicroStation V8i Curve Tools ____________________________81Edit Control Points__________________________________82Change Curve Order ________________________________82Change Curve Closure _______________________________82Edit Weights ______________________________________82Edit Kinks ________________________________________83Edit Knots_________________________________________83Edit Nodes _______________________________________84Fair Curvature _____________________________________84

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Deform Curve _____________________________________84Curve Handlebar ___________________________________85Split Curve ________________________________________85

Linear Elements _______________________________________86NURBS in more detail _______________________________86Degree and Order __________________________________86Control Points _____________________________________87Knots ____________________________________________87Knots and Control Points_____________________________88Evaluation or Basis Rule _____________________________88B‐spline curves ____________________________________89Accuracy _________________________________________90Curve types _______________________________________90Place B‐spline Curve tool_____________________________91Place Composite Curve ______________________________100Conic and Spiral Curve tools __________________________105Place Conic________________________________________105Place Helix tool ____________________________________108

Challenge Exercise _____________________________________111Marine Design ‐ Hard Chine Hulls ______________________111Drawing a Catenary_________________________________114


Basic 3D Solids ______________________________________117Module Overview______________________________________117Module Prerequisites___________________________________117Module Objectives_____________________________________117Introductory Knowledge ________________________________118


3D Workflows_________________________________________118Interactive handles to control 3D objects during creation___119Solids Modeling ____________________________________119Surface Modeling tasks ______________________________120Feature Based Solids Modeling tasks ___________________121

3D Primitive Solids _____________________________________122Slab Solid _________________________________________123Place Sphere ______________________________________123Place Cylinder _____________________________________124Place Cone ________________________________________124Place Torus _______________________________________125Place Wedge ______________________________________125Place Pyramid Solid _________________________________126Elliptical Cone Solid _________________________________128

Feb-09 v MicroStation V8i Everything 3DCopyright © 2009 Bentley Systems, Incorporated

Table of Contents

Ellipsoid Solid______________________________________129Regular Polyhedron_________________________________129

Create Solids Toolbox __________________________________131Solid By Extrusion __________________________________131Solid By Revolution _________________________________136Solid By Thicken Surface _____________________________139Linear Solid _______________________________________140

Challenge Exercises ____________________________________142Module Review _______________________________________143


Advanced Solid Modeling _____________________________145Module Overview______________________________________145Module Prerequisites___________________________________145Module Objectives_____________________________________145Introductory Knowledge ________________________________146


Working Area _________________________________________146Solids Modeling Task ___________________________________148Solid By Extrusion Along ________________________________148

Shell Solid tool_____________________________________158Solid by Thicken Surface tool _________________________162Replace Face ______________________________________164

Boolean tools _________________________________________164Unite Solid tool ____________________________________164Intersect Solids tool_________________________________167Subtract Solids tool _________________________________169Cut Solids by Curves tool_____________________________172Fillets and Chamfers ________________________________176Fillet Edges tool ____________________________________176Chamfer Edges tool _________________________________177Taper Solid tool ____________________________________183Edit 3D Primitive tool _______________________________187


Solid Utilities _______________________________________193Module Overview______________________________________193Module Prerequisites___________________________________193Module Objectives_____________________________________193Introductory Knowledge ________________________________194


Table of Contents vi Feb-09Copyright © 2009 Bentley Systems, Incorporated

Utility Tools __________________________________________195Align 3D tool ______________________________________195Change SmartSolid Display tool _______________________206Extract Face or Edge Geometry tool ____________________208Compute Intersections tool __________________________211Convert To Solid ___________________________________211


Conceptual Modeling ________________________________215Module Overview______________________________________215Module Prerequisites___________________________________215Module Objectives_____________________________________215Introductory Knowledge ________________________________216


Conceptual Modeling Tools ______________________________217Draw on Solid _____________________________________217Modify Solid Entity _________________________________219Delete Solid Entity __________________________________220

Conceptual Modeling Basics _____________________________220Drawing lines on a Solid face _________________________220Projecting lines on a Solid face ________________________222

Create a Conceptual Design _____________________________223Module Review _______________________________________227


Solid Modeling Challenge Exercises _____________________229

Introduction to Feature Modeling ______________________245Module Overview______________________________________245Module Prerequisites___________________________________245Module Objectives_____________________________________245Introductory Knowledge ________________________________246


Feature Modeling Task _________________________________247Feature Modeling versus Solid Modeling ___________________248Creating Feature‐Based Solids____________________________248

Seed Files and Feature Modeling ______________________248Working Area and Feature Modeling ___________________249Creating Feature‐Based Solids ________________________249

Modifying Feature‐Based Solids __________________________253

Feb-09 vii MicroStation V8i Everything 3DCopyright © 2009 Bentley Systems, Incorporated

Table of Contents

Modifying features parametrically _____________________253Modifying one or more blends of a group _______________253Modifying holes____________________________________256Modifying the underlying solid ________________________257

Manipulating Features__________________________________259Modifying and Manipulating Interactively __________________261The Features Toolbox __________________________________264

Cut Feature tool ___________________________________264Sweep Edge Feature tool ____________________________266Boss and Protrusion Feature tools _____________________267Rib Feature tool____________________________________269Thin Shell feature __________________________________271

Modeling Methods_____________________________________273Module Review _______________________________________275


Advanced Feature Modeling __________________________277Module Overview______________________________________277Module Prerequisites___________________________________277Module Objectives_____________________________________277Introductory Knowledge ________________________________278


Dimension Driven Design________________________________278The Purpose of Dimension‐Driven Design _______________279How does it work?__________________________________279Glossary of terms __________________________________280Dimension Driven Design task_________________________281Geometric constraints_______________________________282

Constraints and Feature Modeling ________________________286Constrain Feature __________________________________286

The Feature Manager __________________________________291Working with Feature Manager _______________________291Viewing a solid at various construction stages____________292Controlling the display of features _____________________292Rearranging feature order ___________________________294

Variable Driven Modeling _______________________________297Feature modeling examples __________________________300

Profile‐Driven Feature Solids _____________________________300Creating profile‐driven feature solids ___________________301Extruded and Revolved features_______________________301Tube Feature ______________________________________303Skin Solid Feature __________________________________304Helix Feature ______________________________________305Thicken Feature____________________________________306

Table of Contents viii Feb-09Copyright © 2009 Bentley Systems, Incorporated

Modifying profile‐driven feature solids _________________307Modifying Face Features ________________________________314

Taper Face Feature _________________________________314Extend Face Feature ________________________________315Spin Face Feature __________________________________317Remove Face Feature _______________________________319Replace Surface Feature _____________________________319Deform Face Key‐in _________________________________321


Introduction to Surfaces ______________________________327Module Overview______________________________________327Module Prerequisites___________________________________328Module Objectives_____________________________________328Introductory Knowledge ________________________________328


B‐spline Surfaces ______________________________________329Module Review _______________________________________334


Surface Creation ____________________________________335Module Overview______________________________________335Module Prerequisites___________________________________335Module Objectives_____________________________________335Surface Modeling______________________________________336Primitive Surfaces _____________________________________336Create Free Form Surfaces ______________________________337Construct Loft Surface __________________________________337

Direction Arrows ___________________________________338Using Loft Elements_________________________________341Loft by Section with Guide Wires ______________________342

Loft Surface By Vertices _________________________________345Swept Surface along Curves______________________________353Helical Surface ________________________________________355Loft Rectangle to Circle _________________________________357Surface by Network of Curves ____________________________360Construct Surface by Edge Curves_________________________361Surface by Corner Points ________________________________364Module Review _______________________________________365


Feb-09 ix MicroStation V8i Everything 3DCopyright © 2009 Bentley Systems, Incorporated

Table of Contents

Surface Modification and Blending _____________________367Module Overview______________________________________367Module Prerequisites___________________________________367Module Objectives_____________________________________367Introductory Knowledge ________________________________368


Modify Surfaces Tools __________________________________369Trim Surfaces tool __________________________________369Trim Surfaces by Curves _____________________________371Untrim Surface tool_________________________________374Stitch Surfaces _____________________________________376Offset Surface _____________________________________378Change Normal Direction ____________________________378Extend Surface_____________________________________380Merge Surface to Edge ______________________________382

Fillet Surfaces Tools ____________________________________382Fillet Surfaces tool__________________________________383Fillet Surfaces along Curves___________________________386Blend Surfaces_____________________________________389


Modify B‐spline Surfaces _____________________________393Module Overview______________________________________393Module Prerequisites___________________________________393Module Objectives_____________________________________393Introductory Knowledge ________________________________394


Modify B‐Spline Surfaces ________________________________394Edit Surface Control Points ___________________________395Change Surface Order _______________________________398Change Surface Closure______________________________400Rebuild Surface ____________________________________400Combine Surfaces __________________________________401Split Surface_______________________________________401Surface Handlebar__________________________________404Twist Surface ______________________________________405


Surface Utilities _____________________________________407Module Overview______________________________________407

Table of Contents x Feb-09Copyright © 2009 Bentley Systems, Incorporated

Module Prerequisites___________________________________407Module Objectives_____________________________________407Introductory Knowledge ________________________________408


Surface Utilities _______________________________________409Convert To Surface _________________________________409Extract Points from Surface/Face ______________________411Extract Iso‐Curves __________________________________413Planar Slice _______________________________________417Compute Intersections ______________________________419Unroll Developable Surface___________________________420Surface By Image___________________________________421Show Surface Curvature _____________________________423Match Surface Settings ______________________________425


Meshes ____________________________________________427Module Overview______________________________________427Module Prerequisites___________________________________427Module Objectives_____________________________________427Mesh Surfaces ________________________________________428Creating a Mesh_______________________________________429

Mesh from Element_________________________________429Mesh By Contours __________________________________431Place Grid Mesh____________________________________432Developable Mesh by Curves _________________________432

Modify Mesh _________________________________________432Mesh Booleans ____________________________________432Combining Feature Models and Meshes ________________435Other Modify Mesh tools ____________________________436

Mesh Utilities _________________________________________438Module Review _______________________________________439


Visualizing a 3D Design _______________________________441Module Overview______________________________________441Module Prerequisites___________________________________441Module Objectives_____________________________________441Introductory Knowledge ________________________________442


Luxology Technology ___________________________________442

Feb-09 xi MicroStation V8i Everything 3DCopyright © 2009 Bentley Systems, Incorporated

Table of Contents

Visualization Toolbox___________________________________442Materials _________________________________________444Animation ________________________________________445

Rendering and Lighting _________________________________445Rendering and lighting settings________________________447

The Render Tool_______________________________________449Rendering as a design aid ____________________________449Rendering modes __________________________________449

Antialiased Rendering __________________________________454View Perspective ______________________________________456Render Settings _______________________________________458

Stroke Tolerance ___________________________________461Shadows _________________________________________461

Lights Task ___________________________________________463Default Lighting ____________________________________463Light Setups _______________________________________464Light Manager _____________________________________465

Global Lighting ________________________________________466Ambient__________________________________________466Flashbulb _________________________________________467Solar_____________________________________________467

Source Lighting________________________________________471Shadow generation from source lighting ________________471Place Light tool ____________________________________472Place Light tool settings _____________________________475_________________________________________________481

Materials ____________________________________________482Material and Projection Tasks_________________________483Pattern maps ______________________________________483Bump maps _______________________________________483Materials stored in DGN _____________________________484Material tables ____________________________________484Material Map sizes locked to aspect of map image ________484The Apply Material Tool _____________________________484

Multi‐Layered Materials ________________________________489Projection modes for Pattern/Bump Maps__________________492

Projection modes for materials________________________492Tools for controlling Material Projections _______________493

The Define Camera Task ________________________________495Setup Camera _____________________________________496Define Camera_____________________________________497Camera action options ______________________________499Controlled Movement_______________________________501

Saving Rendered Images ________________________________501Saving a rendered image_____________________________502Viewing a saved image ______________________________503

Distributed Rendering __________________________________504

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Simplified setup for Distributed Rendering ______________504Distributed Rendering Related dialogs __________________505


Using Dynamic Views ________________________________507Module Overview______________________________________507Module Prerequisites___________________________________507Module Objectives_____________________________________508Introductory Knowledge ________________________________508


Glossary _____________________________________________509Dynamic Views Overview________________________________510

Take a picture, it will last longer _______________________511General workflows _________________________________512

Dynamic View Workflow Task ____________________________513View Setup________________________________________5232D or 3D sheets ____________________________________535


Importing and Exporting Drawings in 3D _________________537Module Overview______________________________________537Module Prerequisites___________________________________537Module Objectives_____________________________________537Introductory Knowledge ________________________________538


Exporting 3D to 2D_____________________________________538Conversion options _________________________________538Exporting Visible Edges ______________________________539

Exporting 2D to 3D_____________________________________543Export to and from Google Earth__________________________544

What Google Earth is________________________________544How it works ______________________________________545Google Earth tools__________________________________546Defining geographic location _________________________546Defining a placemark monument ______________________547Removing placemark monuments _____________________549Adding Hyperlinks __________________________________549Exporting files _____________________________________551Capture Google Earth Image__________________________555Synchronizing Views ________________________________556

Feb-09 xiii MicroStation V8i Everything 3DCopyright © 2009 Bentley Systems, Incorporated

Table of Contents

Follow Google Earth View tool ________________________556Control in Google Earth______________________________5563D Warehouse_____________________________________557Working Offline ____________________________________557Play Camera Animation in Google Earth_________________557

Creating PDF Output with 3D Content _____________________558Integrating 3D PDF Annotations into PDF documents ______559Adding links and bookmarks __________________________560Using JavaScript to control 3D annotations ______________560Creating a 3D PDF __________________________________560


Course Summary ____________________________________569Course Summary ______________________________________569Course Review ________________________________________570


Table of Contents xiv Feb-09Copyright © 2009 Bentley Systems, Incorporated

Course Overview

Course Description

MicroStation V8i is often used to produce 2D drawings. In addition to the comprehensive array of 2D tools, MicroStation provides a wealth of 3D tools.

This course covers all aspects of 3D design, using the full suite of MicroStation V8i 3D tools along with practical modeling exercises.

Target Audience

This course is recommended for the following audience:

• Designers

• Architects

• Engineers

• 3D Modelers

Prerequisites

The following is a mandatory prerequisite:

• Expert in MicroStation 2D

• Knowledge of AccuDraw

Either one of the following is also helpful:

• Expertise with other advanced modeling software

• Expertise with animation software

Feb-09 1 Course Overview

Copyright © 2009 Bentley Systems, Incorporated

Course Objectives

Course Objectives

After completing this course, you will be able to:

• Use 3D view controls to see what you need when you need to

• Use 2D tools in 3D models

• Apply AccuDraw in 3D

• Use 3D primitive solids for basic forms and design

• Modify and do basic analysis of solids

• Create and modify B‐spline curves and surfaces

• Create parametric feature models

• Use advanced feature modeling techniques to increase 3D efficiency

• Apply conceptual modeling tools for push/pull modeling

• Use mesh modeling for site design and soil modeling

• Apply drawing composition tools to create 2D production drawings

• Use the rendering and animation tools to make your 3D model photo‐realistic

Modules Included

The following modules are included in this course:

• Course Overview

• 3D View Controls

• AccuDraw in 3D

• B‐Spline Curves

• Basic 3D Solids

• Advanced Solid Modeling

• Solid Utilities

• Conceptual Modeling

• Solid Modeling Challenge

• Introduction to Feature Modeling

• Advanced Feature Modeling

Course Overview 2 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Introductory Knowledge

• Introduction to Surfaces

• Surface Creation

• Surface Modification and Blending

• Modify B‐Spline Surfaces

• Meshes

• Visualizing a 3D Design

• Using Dynamic Views

• Importing and Exporting Drawings in 3D


Before you begin this course, let's define what you already know.

Questions

1 Name three AccuDraw shortcuts.

2 Explain the difference between designing an object and capturing the design intent of an object.

3 True or False: Rendering and animation tools require installation of additional software.

Feb-09 3 Course OverviewCopyright © 2009 Bentley Systems, Incorporated

Answers

1 O, RE, ?

Over thirty shortcuts exist. Use the ? shortcut to see them all.

2 Creating a design results in a collection of graphic geometry. You may not know how it was designed. Even if you had knowledge of how the geometry was designed, recreating it could be a tedious process.

Capturing design intent creates a recording of the steps that were taken to design, as well as the graphic geometry. Repeating the design and making modifications (iteration) is easy since all the steps involved are recorded.

3 MicroStation includes rendering and animation software.

Feb-09 4 Course OverviewCopyright © 2009 Bentley Systems, Incorporated

3D View Control

Module Overview

All the 2D view controls, such as Fit View, Zoom In and Out, Window Area, and Pan, can be used in 3D. As in 2D, elements to the left, right, above, or below can be excluded from a view by zooming in or windowing so that the elements are outside the view's area.

There are also a number of 3D specific viewing tools. 3D views have depth. You can exclude the display of elements located in front of, or behind, an object by applying a Clip Volume or Clip Mask.

It is a good idea to practice View Control tools for 5 minutes at the start of every 3D session, before doing any other work.

Module Prerequisites

• Knowledge of MicroStation 2D view controls

Module Objectives

After completing this module, you will be able to:

• Use 3D view control tools to navigate in 3D space

Feb-09 5 3D View Control




Before you begin this module, let's define what you already know.

Questions

1 True or False: You can view a 3D design from any direction and even move inside it.

2 Define a MicroStation model.

3 In 2D models, you work on a design plane. What is the working area in 3D?

Answers

1 True.

2 Each model is an independent graphical space, with its own origin point, units of measurement and can be 2D or 3D.

3 In 3D models, the 2D design plane becomes a 3D cube, known as the design cube.

View Rotation

When you work in a 2D model, you can rotate the view. Visually, this is like rotating the xy‐plane about a perpendicular, or z‐axis. When you are working in a 3D model, you can rotate the view about any axis (the x‐, y‐, or z‐axis). The visual effect on screen is like rotating the design cube. You can rotate any view to a standard rotation or to any arbitrary view orientation.

When you dynamically rotate a view, you can use any of the following methods.

Using the mouse

• Shift key + middle mouse button to Rotate about Center

• Pressing the left mouse button completes the rotation

Using a tool

• View Rotation tool

3D View Control 6 Feb-09Copyright © 2009 Bentley Systems, Incorporated

View Rotation

• Standard View Rotation

Rotate VIew icon and Standard VIew icons

These tools require a data point to start and a second data point to complete the rotation

The Rotate View tool

Access to View Rotation is found in the view control toolbox at the top of each view window. You can also use keyboard mapping, pressing 4 + 6 + 1 to activate the Rotate View tool, or select Tools > View Control to open a floating toolbox.

Use view rotation to rotate a model to access a face that would otherwise be behind another. The tool settings have two options that control the method of rotation.

Cube rotation rotates the view as follows:

• Moving the pointer up or down rotates the view about its x‐axis

• Moving the pointer left or right, when Preserve World Up is:

Enabled: Rotates the view about the model’s z‐axis

Disabled: Rotates the view about its y‐axis

Feb-09 7 3D View ControlCopyright © 2009 Bentley Systems, Incorporated

View Rotation

Sphere rotation rotates the view about a center point. A dynamic sphere, and associated graphics, help you define the rotation. Slide settings let you control the size and transparency of the sphere as follows:

• Small/Large slide control: Lets you define the size of the sphere graphic in the view

• Opaque/Clear slide control: Lets you define the transparency of the sphere in the view

Exercise: Rotating a view using the Cube option

1 Set the following in the File Open dialog:

User: examples

Project: General

2 Open Basic_Solids.dgn.

3 Open the Booleans model.

4 Select the Rotate View tool from View 1’s view control toolbox, with the following tool settings (click the Show Extended Settings arrow to view the settings for Rotation):

Method: Dynamic


View Rotation

Cube rotation

Preserve World Up: Disabled

Crosshairs appear in the center of the view, denoting the center of the rotation.

5 Enter a data point on the right side of View 1.

The pointer changes shape and the crosshairs become a large dot. There is a smaller dot at the pointer’s starting position.

6 Move the pointer to rotate the view interactively.

Note that moving the pointer vertically rotates the view about its horizontal (x) axis. Moving horizontally rotates the view about its vertical (y) axis.

7 Reset.

This cancels the rotation and returns the view to its original orientation.

8 Select the Rotate View view control with the following tool setting:

Preserve World Up: Enabled

9 Enter a data point on the right side of View 1.

10 Move the pointer to rotate the view interactively.

Note that moving the pointer vertically rotates the view about its horizontal (x) axis. Moving horizontally rotates the view about the model’s (z) axis. This has the visual effect of spinning the model about its vertical (z) axis no matter what the rotation of the view.

11 Enter a data point to complete the rotation.


View Rotation

ith

Exercise: Rotating a view using the Sphere option

1 Continuing in Basic_Solids.dgn, in the Booleans model, select Rotate View wthe following tool setting:

Sphere rotation

Crosshairs appear at the center of the view and a shaded sphere surrounds them.

2 Use the Small/Large and Opaque/Clear sliders to adjust the size and transparency of the sphere as desired.

3 Following the status bar prompt, enter a data point somewhere within the region of the sphere.

The crosshairs are replaced by a dot, with a smaller dot indicating the start point of the rotation.

4 Move the pointer to rotate the view about the center of the sphere.

The arrow graphic that appears on the sphere gives you a visual indication of how you are rotating the view.


Rotating to a standard view

The standard view orientations can be selected from the Rotate View tool’s drop‐down menu in each view window. You can also use keyboard mapping key‐ins, or you can open the View Rotation tools as a toolbox. Remember that when you use key‐ins, or use the view rotation tools from the toolbox, the tool applies to the active view.


View Rotation

4

ess

Exercise: Rotating to standard views using various view control options

1 Continuing in Basic_Solids.dgn, in the Booleans model, open Views 2, 3 and and Fit View in each.

2 Select Window > Tile.

3 Select Rotate View (4 + 6 + 1), with the following tool setting:

Method: Top

4 Following the status bar prompt, enter a data point in View 1.

You can continue to enter data points in other views to change them to a Top rotation.

5 Click Rotate View to open the drop‐down menu and select Open as ToolBox.

6 Click the title bar of View 3 to make it the active view.

7 In the View Rotation toolbox, select Right View.

View 3, the active view, is rotated to a Right view.

8 Click in the title bar of View 2 to make it the active view.

9 In the View Rotation toolbox, select Front View.

10 Click the title bar of View 4 to make it the active view.

11 With focus at Home, press 4 + 6 + 5 to rotate View 4 to Isometric.

Rotating a view using the mouse

The mouse wheel or button can be used for several view controls. As in 2D, you can double click the wheel to Fit View. Single click the wheel for a dynamic view Pan. Roll the wheel to Zoom In and Out.

You can rotate the view using the mouse and the key‐in ROTATE VIEW DRAG.

Exercise: Rotate view about center

1 Continuing in Basic_Solids.dgn, in the Booleans model, press the Shift key, prthe middle mouse button and click in View 2.

2 Release the buttons and drag the mouse.

3 Enter a data point to complete rotation, or reset to return to the previous rotation.

4 Click View Previous to return to the previous rotation.


View Rotation

ss

The crosshairs now are located at the left vertical edge of the geometry.

Exercise: Rotate about any point

1 Continuing in Basic_Solids.dgn, in the Booleans model, press the Alt key, prethe middle mouse button, and click in View 2.

As you move the pointer to rotate the view, note that rotation now is around the defined point.

2 Move the pointer over the plus sign at the center of the sphere to relocate the point about which to rotate.

3 Move the sphere to the lower right and note that you can snap to objects.

4 Enter a data point to complete the move of the rotation sphere.

5 Following the status bar prompt, begin rotation.


7 Return the view to Isometric.

8 Fit View.

9 Select File > Close.


Fitting 3D Views

You can rotate the view using the mouse and the key‐in ROTATE VIEW FROM CURSOR.

Additional 3D mouse view controls are:

• Shift key +roll is Pan with Zoom

• Ctrl key + middle button click is Rotate about point

• Ctrl key + roll is walk forward/backward

• Alt +roll is Pan left or right

Fitting 3D Views

In both 2D and 3D models, the Fit View tool lets you select whether the fit applies to elements in the Active file, References, Rasters, or All files associated with the view.

• When you fit a view in 2D, the area of the view is altered to display all elements located on the levels currently turned on.

• In 3D models, there are more choices relating to the clipping planes.

• All ‐ Display all displayable elements in the active model file and any attached references.

• Active ‐ Display all displayable elements in the active model file.

• Reference ‐ Display all displayable elements in attached references, if any.

• Raster ‐ Display all displayable elements in attached raster references, if any.

Clip Volume

During a design session, you may want to work on a particular element and rotate it to view from various angles. When you do this with clipping planes set,


Clip Volume

however, parts may disappear or other elements appear in the display depth. MicroStation’s Clip Volume tools let you select a discrete volume, within the design cube, for display.

This tool is helpful when you have elements on the same level and you do not want to see all of them.

You can use 2D or 3D elements to define the volume. When you use a 2D shape, the clipping volume is created by sweeping the 2D shape through the entire model. The sweep direction is perpendicular to the plane of the 2D element. MicroStation creates a 2D clipping shape using

active attributes.

When a 3D element is used, it defines the entire clip volume.

Before Clip Volume


Clip Volume

After Clip Volume

Operations, such as view rotation, fence processing, hidden line removal, and rendering, honor the clip volumes. They ignore any elements that are not displayed within the defined volume for the view.

Clipping elements may consist of any solid, other than spheres or feature solids. Closed extrusion, cylinders, or closed planar elements (shapes, circles, ellipses, complex shapes, grouped holes) can be used. If a planar element is chosen, or you use the clipping elements by points options, the clipping volume is generated by sweeping the planar element through the entire model. Planar elements may be selected in any view, because the sweep direction is orthogonal to the plane of the element. Similarly, clip elements that you define by points may be drawn in any view. AccuDraw can be used to set the correct orientation of the clip element.

Set Clip Volume options using icons in the tool settings.

• By Element applies a clip volume from an existing element.

• By Section Plane (new for MicroStation V8i)

• By 2 Points lets you apply a clip volume by defining a rectangular clipping element with 2 data points


Clip Volume

• By Polygon lets you apply a clip volume by interactively defining vertices of a polygon with data points. The polygon can be closed by entering a data point at the start point, or by clicking the Close Element button.

• By Element Range applies a clip volume that encloses the range of a selected element or group of elements. If a selection set is active, the clip element will enclose the entire group of elements.

• Show/Hide Clip Element toggles the display of a view's clip volume element. Same function as Display Clip Element.

• Clear Clip Volume removes the current clip volume (but not the element) from a view.

Clip Volume Extended Options are set at the bottom of the tool settings.

• Apply Clip Volume from Named Fence creates a clip volume from the named fence, selected from the list, and applies the clip volume to the active view.

• Delete deletes the named fence selected in the named fence list.

• Save creates a named fence from the clip volume in the active view is created.

Clip Volume Options

By Element

Apply Clip By Section Plane


Clip Volume

Apply Clip By 2 Points

Apply Clip Volume By Polygon

Clip Volume By Section Plane

There are two methods for creating a clip volume by section plane.

• Apply Clip By Section Plane located in the Create Clip Volume tool settings.

• Place Fitted Section. A Fitted Section is a section cut throughout the XY, YZ or XZ plane relative to the Absolute Auxiliary Coordinate System.


Clip Volume

Here is the Top View and Isometric View of the train engine and tanker.

User: Examples

Project: Plant

File: ...\Designs\BSI700‐0100‐RRTrack.dgn

Top View

Isometric View

In this example, a Place Fitted Section is used and an XY plane is created in the Isometric view. The Clip Element is displayed in both views with editing handles active.


Clip Volume

Here are the results after moving the Clip Element Handles in the XY direction.

The Top view shows the Clip Element but the Clip Volume is displayed in the view selected when creating the Clip Volume, which was the Isometric view. Here is the Clip Volume after Selecting the Show or Hide Clip Element tool.

Clip Volumes and View Attributes

The View Attributes dialog includes Clip Volume Settings. When a view contains a Clip Volume, the View Attributes dialog will display a Clip Volume collapsible section. The settings on this section provide various ways to display the Clip Volumes.

In this view, the Clip Volume Settings of the View Attributes Settings are set to display the Forward volume of the Clip Element with the From View option enabled. The Back, Cut and Outside options are disabled.


Clip Volume

Here is the same view with different options selected from the Clip Volume Settings.

Clip Volume Settings and Display Style

When a Display Style is created or an existing style is modified, enabling the Clip Volume box in the Display Style window will place the style as an additional


Clip Volume

option in the Clip Volume Settings. Clicking on the magnifying glass will open the Display Styles dialog.

Applying a clip volume

You can use a clip volume to isolate a part of the model so that you can work on it without the confusion from the display of other parts of the model.

Exercise: Applying a clip volume by 2 points.


Project: Plant

2 Open BSI700‐A0101‐PumpHouse.dgn.

3 From the View Control or the Clip Volume toolbox, select Clip Volume with the following tool settings:

Apply Clip Volume By 2 Points


Clip Volume

Display Clip Element: Enabled

4 In the View Rotation toolbox, select Top View.

5 Enter data points to create a Clip Element.

6 Enter a data point in the View, to accept the clip volume.

7 From the View Control or the Clip Volume toolbox, select Clip Volume and Show or Hide Clip Element, then select view. The clip element will disappear.

8 Use Shift + middle mouse button (press in), or select Rotate View to rotate the View.

Note that only the elements in the clip volume are visible during the rotation.


Clip Volume

9 In the View Rotation toolbox, select Isometric View.

10 Fit View.

No other elements appear in the view.

11 To remove the Clip Volume select the Clear Clip Volume tool and enter a data point in the view.

Exercise: Applying a clip volume by section plane.


Project: Plant

2 Open BSI700‐A0101‐PumpHouse.dgn.

3 From the View Control or the Clip Volume toolbox, select Clip Volume with the following tool settings:

Apply Clip Volume By Section Plane


Clip Volume


4 In the View Rotation toolbox, select Top View.

5 Enter 2 data points to create a section through the Pump House.

6 In the View Rotation toolbox, select Isometric View.


Clip Volume

7 Open the View Attributes dialog using the View Control tool or by pressing Ctrl+B.

Note: Since a clip volume exists in View 2, there is a Clip Volume Settings tab.

8 The forward and back view style of the section plane are displayed on the Clip Volume Settings tab, and are set to “From View”.

9 Select the “Outside” option for the Back area of the section plane and the view displays dashed lines to indicate the Back of the section plane is now hidden.

10 Enable the display of the Cut area. The “From View” will display by default.


Clip Volume

11 Change the display option of the Forward area of section plane to Outside. The new display of the clip volume section should look like the following view.

12 Use the Element Selection tool and select the section clip element.

13 The boundaries of the interactive clip element display.


Clip Volume

14 Move the green handle to re‐position the section plane and move the blue handle to modify the size of the Forward area of the section plane. Clear the clip element selection by a data point in the view.

15 Modify the Clip Volume Settings:


Clip Volume


Manipulating a clip volume from a second view

With a clip volume active, you can restrict the display of elements to just those that you want to see. Once a clip element has been created, you can manipulate it to change the clip volume and the information being displayed. If you later move, or modify a clipping element, the clip volume is also moved or modified. If you delete a clipping element, the view clipping is removed. Clipping elements can be manipulated or modified with the standard MicroStation tools.

Once a clip volume has been applied to a view, you can switch the clipping on and off in the View Attributes dialog using the Clip Volume check box. You can toggle display of the clip element using the Show or Hide Clip Volume Element icon in the tool settings.

Exercise: Manipulating a clip volume

1 Continuing in BSI700‐A0101‐PumpHouse.dgn, select Clip Volume.

2 Open Views 1 and 2, set View 1 to Front and set View 2 to Isometric then Fit View in each window.


Clip Volume

3 From the Clip Volume toolbox, select Place Fitted Section and place a data point in view 2.

4 Select Move (3 + 2).

5 In View 1, snap to the clip element and move it in the ‐Z direction.

View 2 displays the new Clip Volume. Experiment with the blue handles to make more changes to the Clip Volume. Here is an example:


Saving clip volumes

You can save clip volumes as named fences for later use. You then can apply them to any view.

Exercise: Save the clip volume


Clip Volume

1 Continuing in BSI700‐A0101‐PumpHouse.dgn, make View 2 the active view.

2 Ensure that the View Attributes > Presentation > Clip Volume attribute is enabled in all views.

3 Create a 2 point Clip Element in View 1 and apply the Clip Volume in View 2. The image should be similar to the following.

4 Select Clip Volume and click the Expand arrow at lower right of tool settings.

5 Click Create Named Fence From Clip Volume.

6 In the Name field, type the name Front Wall and press Enter.


Clip Volume

You now can apply this clip volume to any view.

Working with multiple clip volumes

Each view in a model can have a clip volume assigned to it. These can be identical, or they can be different.

Exercise: Create a second clip volume

1 Continuing in BSI700‐A0101‐PumpHouse.dgn, select Clip Volume with the following tool settings:

Apply Clip Volume By 2 Points


2 In View 1, enter data points to isolate the back wall.

3 Enter a data point in View 3.

4 Fit View 3.


Clip Volume

Views 2 and 3 now have different clip volumes applied to them.

5 Save the clip volume as a named fence named Back Wall.

Exercise: Apply saved clip volume to a view


2 Select Clip Volume and select the named fence Front Wall in the tool settings.

3 Click Apply Clip Volume By Named Fence.


Clip Volume

The view updates to display only the pump house front wall.

4 Select the named fence Back Wall in the tool settings.

5 Click Apply Clip Volume By Named Fence.

The view updates to display only the back wall.

Saving clip volumes in this manner lets you quickly set up views to work on specific parts of a design. Once a clip volume is defined for a view, it remains with that view until you clear it. Tools such as the Fit View tool will not change the extents of a clip volume.

Exercise: Clear a clip volume

1 Continuing in BSI700‐A0101‐PumpHouse.dgn, click Clear Clip Volume in the tool settings.


3 Fit View 2.


Clip Volume

The entire model is displayed again.

Using a clip mask

A clip mask has the opposite effect to that of the clip volume. A clip volume defines what to display, but a clip mask defines what not to display. Procedures for creating and using clip masks are identical to those for clip volumes. You can apply clip masks to views that have had a clip volume applied.

Similarly, you may want to work on part of a model, while hiding another part of it.

If the elements all are on the same level, you can use the Clip Mask tool to mask the elements that are not required.


Clip Volume

Exercise: Apply and clear a clip mask


2 Select Clip Mask from the view control toolbox.

The tool settings are identical to the Clip Volume tool. The named fences you created previously can be used with clip masks too.

3 Select the named fence Back Wall in the tool settings.

4 Click Apply Clip Mask By Named Fence.

The view updates and the back of the pump house is masked from the view. Fitting and rotating the view will not cause it to reappear.

Clearing a clip mask is the same as a clip volume.

5 Click Clear Clip Mask in the tool settings.




Display Styles Dialog


The Display Styles Dialog is for modifying and creating custom display styles.

You can access the Display Styles Dialog from the following locations:

• Settings > Display Styles... or Tools > View > View Control

• Select from the View Toolbox the Open Display Style Dialog icon.

Note: Display styles are typically saved as shared resources in DGN libraries. Standard display styles are provided with MicroStation V8i, and cannot be deleted.



Understanding Display Style dialog tools.

1 Wireframe ‐ Tool settings:

No settings

2 Hidden Line ‐ Tool settings:

Display: Hidden Line

3 Filled Hidden Line ‐ Tool settings:

Display: Filled Hidden Line

4 Smooth ‐ Tool settings:

Display: Shaded



5 Illustration ‐ Tool settings:

Display: Shaded

Display Visible Edges: Enabled (Black)

Background Color: Enabled (White)

Note: The Display Styles Dialog setting “Usages” when enabled, determines if the display mode is created in view window or Clip Volume or both.

Exercise: Create a custom display style

1 Open BSI700‐S0501‐UnloadingPlatform.dgn, make View 2 the active view.

2 Select Settings > Display Styles...

3 Select New and type over Untitled with the name “Custom Display”.

4 Set the Display Styles settings as follows:

Display: Shaded

Enable No Material: Select the Material option

Select magnifying glass: Select Platform Frame material option

Enable Background color: Select Gray #48option

Enable Usages: View

5 In View 2, select the View Display Mode tool drop down arrow and select Custom Display.


Perspective

Perspective

Every time you turn on perspective in a view, you turn on the Camera (View Attributes > Camera). You can turn perspective on specifically using the View Perspective tool.

A single data point in the view center starts the 3 point perspective, and movement away from the center changes the amount of perspective. Selecting the View Perspective tool and double clicking in the center of the view sets the view to parallel projection, or turn off the Camera in View Attributes.

Additional options are available if you click and hold the View Perspective tool or open it as a toolbox.

• View Perspective interactively set perspective in a view

• Wide Angle sets perspective in a view to match an extra wide angle camera lens

• Normal sets perspective in a view to match a normal camera lens

• Telephoto sets perspective in a view to match a telephoto camera lens

• Two Point Projection sets perspective in a view to 2 point projection. Hidden by default

• Camera Off turns off a view camera and return to parallel projection

Saved Views dialog

Used to name, save, delete, import, apply and recall saved views. Saving a 3D view allows you to quickly recall a view with specific attributes. It is important to create and use Saved Views in 3D, since you will want to return to a known position many times. They are helpful for design, navigation, rendering and animation. Camera and Clip Volume settings are available for saving or recall.


Saved Views dialog

Open the dialog by selecting Utilities > Saved Views, selecting View Save/Recall from a view window control menu, or pressing F6.

Understanding the Saved Views dialog.

The Saved Views dialog contains controls that are used to apply a saved view to a view in the design file. The list box shows the name, description and model of each view saved. To apply a saved view, use the following options:

Apply to Selected Views. Select this tool and click in a selected view window or select the view number.

Apply to open views. All opened views will display the Saved View.

Double click the entry in the Saved View dialog list. The selected view number will display the Saved View.

Active File ‐ This icon displays optional settings by clicking on the drop‐down list box.


Saved Views dialog

Note: A link is a pointer to project data and a link set is created when you use Project Explorer (File > Project Explorer).

Create Saved View ‐ Opens the Create Saved View dialog where you name and describe the view you are saving. The view can be a saved, section, elevation,

detail or plan view. A Clip Volume can also be added to a Saved View Option.

Exercise: Create a Saved View

1 Open BSI700‐S0501‐UnloadingPlatform.dgn, open Views 1 through 4, select to Window > Tile, and then Fit View for each view.

2 Set Display Mode to Wireframe for each view.

3 Window in on the top of the Unloading Platform in View 4.

4 Set Display Mode to Smooth with Shadows and apply the View Perspective Extra Wide Angle.

5 Press F6 to open the Saved View dialog, click Create Saved View, and save the new view in View 4:


Saved Views dialog

Name: Top Platform

Description: Top platform with wide angle view

6 Click in View 4 to select the source view.

7 In the Saved Views dialog, set the View number to View 3 and double click the Top Platform saved view in the saved view list box.

8 In the Saved View dialog list box, click on the area below the header “Clip Volume” and select the clip volume named StairSide.

View 3 displays a clip volume in the saved view.


Saved Views dialog

9 In the View Attributes dialog, display the Outside portion of the clip volume and set the option to Outside to display dashed lines representing the outside of the clip volume.


Module Review

Module Review

Now that you have completed this module, let’s measure what you have learned.

Questions

1 When rotating a view using cube rotation, what does the Preserve World Up option do?

2 True or False: When you use key‐ins, or use the view rotation tools from the toolbox, the tool applies to the active view.

3 What is the Active Depth?

4 What is the difference between using a 2D as opposed to a 3D element to define a clip volume?

5 How do you modify a clip volume?

6 How do you save a clip volume?

7 What is the difference between a clip mask and a clip volume?

8 Where do you modify the display of the Front and Back portion of a Clip Volume?

Answers

1 When you are moving the pointer left or right, if Preserve World Up is enabled it rotates the view about the model’s z‐axis. If it is disabled it rotates the view about its y‐axis.

2 True.

3 The Active Depth is a plane, parallel to the view or screen, which is always located within the Display Depth of a view. The Active Depth of a view determines where data points fall by default. If you enter a data point in a 3D view, without snapping to an existing element, it falls on the Active Depth plane.

4 When you use a 2D shape, the clipping volume is created by sweeping the 2D shape through the entire model. When a 3D element is used, it defines the entire clip volume.

5 Clipping elements can be manipulated or modified with the standard MicroStation tools.


Module Review

6 You can save clip volumes as named fences. To do so, click Create Named Fence From Clip Volume in the Clip Volume tool settings.

7 A clip mask has the opposite effect to that of the clip volume. A clip volume defines what to display, but a clip mask defines what not to display. Procedures for creating and using clip masks are identical to those for clip volumes.

8 The Front, Back, Cut and Outside area of a Clip Volume is modified in the View Attributes dialog.


AccuDraw in 3D

Module Overview

AccuDraw is an intelligent drawing aid that interprets the position of the pointer relative to previous data points, view orientation, and coordinate system. Using AccuDraw, you can quickly enter additional data points that build on those entered previously.


• Knowledge of AccuDraw in 2D

• Knowledge of basic 3D view controls and 3D planes

Module Objectives


• Design with AccuDraw in a 3D environment

• Use Auxiliary Coordinate Systems to control drafting planes

• Use AccuDraw 3D shortcuts

Feb-09 47 AccuDraw in 3D





Questions

1 Name the two basic AccuDraw interface components.

2 What must have the focus for AccuDraw shortcuts to work?

3 What are the operational steps when using AccuDraw?

4 How do you place the AccuDraw compass at a snap point?

Answers

1 AccuDraw compass and AccuDraw window.

2 The AccuDraw window.

3 1. Enter a data point using either precision input, or a data point, to fix the location of the compass.

2. Move the pointer in the direction in which you wish to draw.

3. Without using the pointer to put focus into the AccuDraw window’s key‐in fields, enter the desired distance value.

4 Use AccuSnap, or issue a manual tentative snap, and use the AccuDraw shortcut <O>.

AccuDraw in 3D 48 Feb-09Copyright © 2009 Bentley Systems, Incorporated

The AccuDraw Drawing Plane

The AccuDraw Drawing Plane

AccuDraw was designed to work with the 3D drawing environment. You can work in a view other than one of the orthogonal views (Top, Front, and Right), but still draw in the orthogonal planes.

Rotated views such as Isometric or Right Isometric display a design more clearly. When working in these views, if you want to draw an object on the Top or Front plane, you can simply rotate the AccuDraw compass to that plane using an AccuDraw shortcut. You do this by rotating AccuDraw’s compass to an orthogonal plane with one of the shortcuts V (view), T (top), F (front), or S (side).

Working in the Isometric view, you can use AccuDraw shortcuts to rotate its compass to the Top (T), Front (F), Side (S) or View (V) orientation

Note: Remember that the focus must be in the AccuDraw window for its shortcuts to work. Press F11, or press Esc and then the space bar to move focus to it.

It is recommended that you work in the Isometric view with the Top, Front and Right views open, placed behind the Isometric view.

3D Element Placement

Placing elements in a 2D file is like drawing on a sheet of paper. All elements are on 1 plane, the x,y plane. When you place the same elements in a 3D file, by

Feb-09 49 AccuDraw in 3DCopyright © 2009 Bentley Systems, Incorporated


default they are placed in the AccuDraw drawing plane. The AccuDraw drawing plane can be rotated to match the view being used, or defined to be a particular rotation.

In the following exercises, you will draw an open rectangular box using 2D blocks.

Exercise: Open the model and draw the base surface


User: untitled

Project: Everything3D

2 Open AccuDraw_3D.dgn from the class data set.

The instructor will provide the location of the data set.

This model displays the ACS triad, which indicates the directions of the 3 axes, in each view. You can toggle the display of the ACS triad in the View Attributes dialog.

3 Select Workspace > Preferences, and then the Task Navigation category and set Presentation to Dialog.

4 In the Task dialog, click the Basic 3D task.

First, using the Top view, you will draw the base of the box. You will use AccuDraw to input precise dimensions. Effectively, this part of the exercise will be no different from working in 2D.

5 Select Place Block (Q + 2 +1).



6 Enter a data point in the lower left corner of the Top view.

7 Move the pointer to the right and, with it indexed to AccuDraw’s x‐axis, type 1.5. Do NOT enter a data point.

8 Move the pointer upward and type 1.25.

9 Enter a data point to complete the block.

10 Fit each view.

The block appears as a line in both the Front and Right views, where it is edge on to the views, like looking at a sheet of paper edge on.

Next, you will use the Isometric view to draw the corresponding front and right faces of the box. You may remember that each view has an active depth, where data points fall by default if you do not snap to an element. Here, you will snap to the existing block that you just drew and use AccuDraw to keep the pointer at that depth in the view.

Exercise: Use Isometric views to draw corresponding faces for the box

1 Continuing in AccuDraw_3D.dgn, select Place Block (Q + 2 +1).

2 In the Isometric view, snap to the left end of the existing block and accept with a data point.

3 Press <F> for the AccuDraw shortcut for Front rotation.



4 Move the pointer to the right, snap to the endpoint and, with it indexed to AccuDraw’s x‐axis, then press <X>, to lock to the x.

5 Move the pointer upward, type 0.5, and enter a data point to complete the block.

6 Fit each view.

For the right face, you can snap to existing elements to place the points.


8 Press <S> for Side rotation.

Note: Press F11 to put focus in the AccuDraw window.

9 In the Isometric view, snap to the bottom left end of the base and accept with a data point.



10 Continuing in the Isometric view, snap to the top of the front surface and accept with a data point.

As you do this, check in the Front and Right views to ensure that you are snapping to the correct points and that the block is being placed correctly.

11 Fit each view.

To complete the box, you can use the Copy tool to copy the existing faces creating the opposite sides. When you copy an element in 3D, it retains its current orientation. That means that a vertical face remains vertical, a horizontal face remains horizontal, and so on.

Exercise: Copy the existing faces to complete the box

1 Continuing in AccuDraw_3D.dgn, select Copy Element (3 + 1), with the following tool setting:

Copies: 1



2 In the Isometric view, identify the block representing the back face at its lower right vertex.

The face is attached to the pointer. As you move the pointer in the other views, the front face element retains its current orientation.

3 Snap to the front right vertex of the base block.

4 Enter a data point to complete the copy and reset.



5 In the Isometric view, identify the block representing the right face at its lower right vertex.

6 In the Isometric view, snap to the back right vertex of the base block and accept to complete the copy.

7 Reset.

8 Click the View Display Mode view control and change the Isometric view’s display to Hidden Line.

9 Use the Rotate View tool to rotate the Isometric view and verify that you have correctly drawn all the surfaces for the open top box.



As you can see, placing elements in 3D is no more difficult than in 2D. In the exercise, you used MicroStation’s views to correctly orient the elements. Of the 4 views, the Isometric view best displays the model. You can see the 3 faces quite clearly.

Using AccuDraw’s rotated drawing plane

You can place elements in the Top, Front and Side alignments using AccuDraw’s <T>, <F> and <S> shortcuts.

AccuDraw’s drawing plane lets you work in any view, while still maintaining the correct plane for the elements being drawn. You can still snap to elements that are not on the current drawing plane and AccuDraw responds accordingly.

As you draw in 3D, you may observe the drawing plane axes change as you enter data points. The alignment of the drawing plane depends on the tool being used and the location of the previous data points. For 3D models, the 3 previous data points are considered, as this is the minimum requirement to describe a planar surface. Where less than 3 data points have been entered, the view orientation is also considered.

Additional shortcuts

• <B> Base Rotation: Rotates the drawing plane to align with the active ACS or the rotation of the view.

• <E> Cycle Rotation: Rotates between 3 main planes; top, front, and side. Pressing E rotates the drawing plane first 90° about its x‐axis, then 90° about its y‐axis, and then back to its original rotation.

In the following exercises, you will work in the Isometric view and let AccuDraw correctly align the elements. As you work through the exercise, use the other open views to check the orientation of the element being drawn, by maximizing and shrinking the Isometric view.

Exercise: Automatic drawing plane rotation in AccuDraw

1 Continuing in AccuDraw_3D.dgn, Pan to an open area of the model.




3 In the Isometric view, place 2 orthogonal blocks as shown.

4 Continuing with Place Block, snap to the vertical face upper right corner.

5 Press <T> to rotate AccuDraw’s drawing plane to Top.



6 Snap to the lower right vertex of the base.

AccuDraw uses the 2 data points plus the view to set the drawing plane orientation. This results in a drawing plane that is not always in alignment with any of the standard Top, Front or Side drawing planes.

7 Snap to the lower left edge of the base and accept with a data point.

AccuDraw’s drawing plane now aligns itself with the plane of the 2 non‐planar data points.

8 Reset to complete.

Non‐orthogonal rotation

Quite often, you will need to rotate the AccuDraw compass to a non‐orthogonal plane; one that is not the Top, Front or Side. Besides the standard non‐planar data



points and view rotation, or non‐planar snapping, several other methods are available. The most common is to use an AccuDraw shortcut.

• RQ ‐ Rotate Quick provides quick, non‐persistent rotation

• RA ‐ Rotate ACS allows you to persistently rotate x and y plane about an origin point. You can clear it by using a standard rotation like T,F, S, V

• WA ‐ Save an ACS rotation

• GA ‐ Recall an ACS rotation

• E ‐ Cycle RotationImportant when using another ACS since T, F or S will break you out of existing ACS

• RX ‐ Rotate about x‐axis

• RY ‐ Rotate about y‐axis

• RZ ‐ Rotate about z‐axis

• RE ‐ Rotate AccuDraw compass to match orientation of an element

• RV ‐ Rotate Active View to orientation of AccuDraw compass

Exercise: AccuDraw and Quick Rotation

1 Continuing in AccuDraw_3D.dgn, select Edit > Undo to undo the placement of the last inclined plane.

2 Select Place Block (Q + 2 + 1).

3 Press F11 and then press <T> for top rotation.

4 Following the status bar prompt, snap to the upper left vertex of the vertical face and accept with a data point.



5 Press <RQ> and, following the status bar prompt, snap to the lower left vertex of the base, then accept the new rotation with a data point.

6 Snap to the right lower vertex of the base and accept the new block with a data point.

Note: An alternate method is to use Place Block with the Method set to Rotated.

To keep a persistent rotation, you can use the AccuDraw shortcut <RA>.

Exercise: Using RA to keep a rotation



1 Continuing in AccuDraw_3D.dgn, select Place Circle (Q + 3 + 1) with the following tool setting:

Method: Center

2 Snap to the upper left vertex of the vertical face, press F11, and then press <O> to set the AccuDraw origin, but do not enter a data point.

3 Press <RA>, keeping the snap point the same, and enter a data point to accept the origin.

4 Snap to, and accept, the upper right vertex of the vertical face to show the x‐axis direction.



5 Snap to, and accept, the lower left of the base to set the y‐axis direction.

6 Press the space bar to change to the rectangular coordinate system.



7 Snap to, but do not accept, the left midpoint of the inclined plane and lock the y‐axis by pressing <Y>.

8 Press <K> to open Keypoint Divisor dialog and set the divisor to 3.

9 Snap to left third of the long edge of the base to set the x‐axis distance, and enter a data point to accept the center point of the circle.



10 Type a distance of 0.2 for the radius and accept with a data point.

Save the rotated ACS with AccuDraw shortcut <WA> and recall it with <GA>.

A quick rotation method is to rotate to an elements plane.

Exercise: Quick Rotation to an element

1 Continuing in AccuDraw_3D.dgn, with focus on AccuDraw, press <T> to set Top rotation.

2 Select Place Circle (Q + 3 + 1), with the following tool settings:

Method: Center

3 Press F11 to put focus in the AccuDraw window.

4 Snap to, but do not accept, the midpoint of right edge of the inclined plane and press <O> to set the AccuDraw origin at the midpoint.

5 Press <RE> to Rotate to Element.



6 Align the compass to the right inclined edge.

7 Enter a data point to accept the rotation.

8 Index to the left and press Enter.

9 Snap to a point one‐third of the way along the bottom edge and enter a data point to place the center of circle.



10 Index to any axis and type a radius of 0.2.

Other tools that rely on the plane orientation also can be used with AccuDraw. For example, the Mirror, Rotate Element, and Array tools all use the plane orientation to define the direction of the mirror, or the axis of rotation.

Locating elements relative to others

There will be occasions when you will locate elements relative to others already present in the model.

In the following exercise, you will place a SmartLine to represent a center line for a pipe.

Exercise: Draw the center line

1 Continue in AccuDraw_3D.dgn.

2 Open the 01_AccuDraw Exercise model.

3 Set the View Display Mode to Smooth with the following tool settings:

Display Edges: Enabled

Display Hidden Edges: Enabled

4 Make the Drawing tasks the active tasks in the Task Navigation dialog.

5 Select Place SmartLine (Q + 1) with following settings:

Segment Type: Lines

Vertex Type: Rounded



Rounding Radius: 1.5

Join Elements: Enabled

6 In the rotated view, snap to the vertex at the point labeled Start here and accept with a data point.

7 Press <T> to switch to the Top plane.

8 Move the pointer down to the left and, with it indexed to the y‐axis, press <Enter> to constrain the point to this axis. (Do not enter a data point.)



9 Type a distance of 35 for Y, and accept with a data point.

10 Staying in the Top plane, index to negative Y and press Enter.

11 Snap to the center of lower, open cylinder face and accept with a data point.



As you snap to the vertex, AccuDraw displays a dashed line, which is perpendicular to the x‐axis, back to the point being placed. This lets you locate the y distance using a 3D snap.

12 Press <F> for Front rotation.

13 Index to the negative y‐axis and press <Enter> to constrain the next point to the y‐axis.

14 With the pointer still snapped to the lower center open cylinder face, accept with a data point.

15 Press <T> for Top rotation.

16 Index to the negative y‐axis and lock by pressing <Y>.



17 Type 30 and accept with a data point.


19 Rotate to see the other side.

20 Repeat for the other 2 directions.




Using Auxiliary Coordinate Tools

MicroStation provides specific tools for creating, modifying, importing and selecting Auxiliary Coordinate Systems. You can find the tools by selecting Utilities > Auxiliary Coordinates or right click and turn on the tool in the Primary Tools toolbox.

An auxiliary coordinate system (ACS) is a coordinate system with an orientation, and/or an origin, different from those of the DGN file coordinates (the Global Origin). Although not exclusively a 3D concept, an ACS is most useful in 3D modeling as a drawing aid.

Tools from left to right are Create a new ACS, Copy ACS, Delete ACS, Import ACS, Define ACS (Aligned with Element), Define ACS (By Points), Define ACS (Aligned with View), Define ACS (Aligned with Reference), Rotate Active ACS, Move ACS, and Select ACS

Active Depth is no longer used, because the location of unsnapped points is controlled by the ACS for a view. Instead of Depth Lock, you now can enable ACS Plane Snap to force unsnapped points to fall on the plane of the ACS.

Auxiliary Coordinates dialog tool features:

• A new ACS can be created using the Create a new ACS tool in the dialog.

• A list box now displays the active ACS on the top line and all ACS’s in the active model.

• All ACS tools are available within the dialog.

• Ability to create, copy, delete or import an ACS.

• Make an ACS active by double clicking on ACS name in list or right‐click on ACS name and select Set Active from options list.

• Other options include ability to match the coordinate system of selected ACS to the active ACS or global coordinates for the model, and deleting or renaming an ACS.



• It is possible to lock the Grid Plane to the active ACS <LP> or F8 function key. This means that the AccuDraw drawing plane shortcuts for Top, Front and Side are relative to the active ACS rather than the Default coordinate system.

• Left click on the Type and change it to None, Rectangular, Spherical, or Cylindrical.

AccuDraw Shortcuts for ACS

• LP ‐ Lock ACS Grid Plane ‐ Toggles ACS Grid Plane lock, which toggles the ACS Plane and ACS Plane Snap locks, and the Grid view attribute for all views.

• LA ‐ Toggles ACS Plane lock.

• LS ‐ Toggles ACS Plane snap lock.

• LZ ‐ Toggles Sticky Z Lock, which is used in conjunction with ACS Plane Snap Lock to force a series of snap points to lie on the active ACS' XY plane (Z=0).

Exercise: Creating and drawing on a new ACS.

1 Continuing in AccuDraw_3D.dgn, open the model 02_ACS_by_points.

2 Select the ACS By Points tool from the Auxiliary Coordinates dialog with the following tool settings:

Type: Rectangular

Other Settings: Disabled

3 Enter the new ACS origin at point 1

4 Define the x‐axis by placing a data point on point 2

5 Enter a data point on point 3 to identify the y‐axis direction, and the new ACS will display.



6 To create a new ACS, click the Create a new ACS tool in the dialog and type a name for the new ACS.

7 Double click the new named ACS.

It will become the Active ACS and will display on the first line or Active ACS line of the dialog.

8 Select Place Block with the following settings:

Method: Rotated

Area: Solid

Fill Type: None

Note: When drawing on a rotated ACS use the AccuDraw shortcut <LA> to lock the ACS Plane.

9 Enter the base point of the block at the midpoint of the edge between points 1 and 3.

10 Enter the second base point of the block at the midpoint of the edge between points 1 and 2.

AccuDraw will automatically rotate orthogonal to ACS2.

11 Move the pointer along the green y‐axis for a distance of 1.

12 Render using the Smooth or Hidden Line View Display Mode.



Define an ACS aligned with a reference file

The following image shows a simple reference attached to the model.

To set the ACS so that it is aligned with the ACS of the Reference, use the Define ACS (Aligned with Reference) tool. Select the Reference and the Reference ACS becomes the active ACS.

ACS interaction with AccuDraw

Use the AccuDraw shortcut <LA> to lock the active ACS plane. This will let you use the <T>, <F> and <S> shortcuts relative to the active ACS.



Use the AccuDraw shortcut <LP> or default function key <F8> to turn on the ACS Plane, ACS Plane Snap and grid for all views. The following image shows the results of using the <LP> or <F8> shortcut.

Separate ACS per View

A new tool in the ACS toolbox lets you assign Auxiliary Coordinate Systems to each view. You can create an ACS for a view with the Define ACS by View tool. You can make the ACS view‐independent by turning on a check box. When a view‐ independent ACS is active, and the ACS triad setting is enabled for the view, the X, Y arrows are displayed as dashed in the view.

To retain the per‐view ACS setting for the next session, you must select File > Save Settings.

When a model created in an earlier version is opened and the ACS Plane lock is not enabled, a view‐independent ACS with an origin of the view center at active depth is created. This lets you start working with the geometry created in the same place as it would have been in the earlier version (at the Active Depth).

You may also right‐click on an ACS in the ACS dialog and select Set Active View.

Projecting Points from and ACS to a Plane

You can use a combination of an ACS and AccuDraw to project points, in the ACS z‐direction, from the ACS plane to the AccuDraw drawing plane. This technique lets you, for example, trace the boundary of a house on to a sloping roofline, as explained in the following workflow.


Module Review

How to Project Points onto a Rotated Plane:

1 Set up an ACS such that the Z direction is the desired projection.

2 Press F8 to lock AccuDraw to the ACS.

3 Select the element placement tool, such as Place SmartLine.

4 Press F11, to set focus to AccuDraw.

5 Key‐in the AccuDraw shortcut RE.

6 In the tool settings, set:

Update Current ACS: Off

Move Origin: On

7 Select the element to which you want AccuDraw aligned and accept with a data point.

8 To commence drawing the element, snap to an element in the ACS plane and accept with a data point.

The point is projected onto the AccuDraw drawing plane.

9 Add more points by snapping to elements in the ACS plane to project the points to the AccuDraw drawing plane.

Module Review


Questions

1 When you place elements in a 3D file, on what plane are they placed by default?

2 How can you move focus to the AccuDraw window?

3 Which view rotation best displays a model?

4 True or False: When you copy an element in 3D, it retains its current orientation.

5 What is the minimum requirement to describe a planar surface?

6 What does the AccuDraw shortcut <RA> do?

7 What is an important thing to remember when using the <O> shortcut to set the AccuDraw origin?


Module Review

Answers

1 When you place elements in a 3D file, by default, they are placed in the AccuDraw drawing plane.

2 Press F11, or press Esc and then the space bar.

3 Isometric (or Right Iso).

4 True.

5 For 3D models, the 3 previous data points are considered, as this is the minimum requirement to describe a planar surface.

6 Use it to keep a persistent rotation.

7 Snap to the desired location, but do not accept.


B‐Spline Curves

Module Overview

In this module, you will examine the Curves creation and modification tools.


• Knowledge of 3D tools in MicroStation

• Knowledge of 2D Drawing tools in MicroStation


Module Objectives


• Use new 3D modification and creation workflows

• Apply new 3D Curve features

• Apply new features of existing tools

Feb-09 79 B-Spline Curves





Questions

1 Name the AccuDraw shortcut used to cycle through rotations.

2 MicroStation creates what type of curves?

3 True or False: Curves can be non‐planar.

Answers

1 E.

This shortcut will cycle through all orthogonal rotations.

2 NURBS or B‐splines.

3 True. You can draw 2D or 3D curves.

3D Workflows

All 3D modeling tools now have a unified workflow that covers that way that you select items for creation and modification, and how you can modify them interactively.

For example, you can now select edges and faces of solids and surfaces for modification with Element Selection. Typically, selecting edges, faces, or vertices, for solids and surfaces is as follows:

• Generally — select single items with a data point, and use Ctrl + data button for additional items.

• Faces — select the solid/surface first, and then dynamics let you select face(s).

• Back Faces — snap to an edge or vertex of a back face.

• Edges/Vertices — direct selection, or through dynamic selection.

B-Spline Curves 80 Feb-09Copyright © 2009 Bentley Systems, Incorporated

MicroStation V8i Curve Tools

Interactive handles to control 3D objects during creation

Interactive handles let you control aspects of 3D objects during creation. For example, you can reverse the direction of surface normals interactively, during construction of fillets, by clicking the direction handles.

Hint: Press F4 to see the current tasks at the pointer.

Alternate Display options exist for the Task Navigation dialog. Right click on the name of a task in the dialog itself or select an icon from the icons displayed aside of the Task name.

List option is useful when learning a new task and Panel option exposes all tools.


Several new tools have been added to the Modify B‐spline Curves toolbox for modifying and manipulating B‐spline curves. Some older commands have been split into separate tools.

Feb-09 81 B-Spline CurvesCopyright © 2009 Bentley Systems, Incorporated


Edit Control Points

This tool is used to show or hide the control points for a B‐spline curve, or to change the number of control points for the curve.

Change Curve Order

Used to change the order of a B‐spline curve, without adding or removing control points. If Preserve Curve Shape is enabled, there is no perceptible change to curve shape but there is an increase in the number of poles on the curve.

Change Curve Closure

Changes open or closed state of a curve.

Edit Weights

The Edit Weights tool lets you select a B‐spline curve, then a control point, to modify its weight using the text field input or the slider. The weight of a B‐spline curve is used to position the curve relative to its control point. By increasing the



weight, you bring the curve closer to the control point. By lowering the weight, you move the curve farther from the control point.

Edit Kinks

The Edit Kinks tool lets you insert or remove kink points. A kink point is a point on the curve where, potentially, curves can have a cusp or sharp point.

In this figure one of the curves has a kink created but needs to be removed to attain a smooth surface

The image on left shows surface with a kink, middle image shows surfaced zoomed in and on right after kink is removed.

Edit Knots

The Edit Knots tool lets you insert or remove knots. A knot is a point on the control polygon of a B‐spline curve. The knot vector collects the different knots



(parameter values) that join the curve. If knots are not evenly spaced then you have non‐uniform curves.

Edit Nodes

The Edit Nodes tool lets you insert node points into a curve, or move them by dragging. Nodes are points on B‐spline curves that can be moved to change the shape of the curve. This tool allows you to have more control of a curve without increasing the order of the curve and increasing computation time.

The image on the far right shows that one node has been added to B‐spline curve.

Fair Curvature

Fair Curvature is used to minimize the curvature variation of (smooth) a B‐spline curve

Deform Curve

Deform Curve is used to deform a curve with degrees of freedom to be added to the region being deformed. The more you add, the more freedom (movement in



x, y and z and rotation in x, y and z) you have to deform the curve. You can also define the percentage of the total curve that is affected by the deformation.

After you have deformed a curve at a localized area you then can use Element Selection tool to move handles and create surface as in right image.

Curve Handlebar

The Curve Handlebar tool lets you identify a B‐spline curve and then define a point on it where the tool displays three handles. The side handles let you deform a curves tangent direction at the defined point. The middle handle lets you drag the point to change the shape of the.

In these images you can see how you can directly modify the local handlebars of a B‐spline curve.

Split Curve

The Split Curve tool lets you split a B‐spline curve by one of the following methods:

• By Numbers splits the curve into equal arc lengths.

• At Kink Points splits the curve at all sharp or cusp points.


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• Into Bézier splits the curve into its Bézier segment curves.

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SmartLines and B‐spline curves are constrained to being planar in 2D. In 3D design files, these elements no longer have this constraint. There are also many other types of 3D curves available.

NURBS in more detail

NURBS curves and surfaces behave in similar ways and share terminology. A NURBS curve is defined by four things: degree, control points, knots, and an evaluation or basis rule.

Degree and Order

The degree is a positive whole number.

This number is usually 1, 2, 3 or 5, but can be any positive whole number. NURBS lines and polylines are usually degree 1, NURBS circles are degree 2, and most free‐form curves are degree 3 or 5. Sometimes the terms linear, quadratic, cubic, and quintic are used. Linear means degree 1, quadratic means degree 2, cubic means degree 3, and quintic means degree 5.

You may see references to the order of a NURBS curve. The order of a NURBS curve is positive whole number equal to (degree+1). Consequently, the degree is equal to (order‐1).

It is possible to increase the degree of a NURBS curve and not change its shape. Generally, it is not possible to reduce a NURBS curve’s degree without changing its shape.


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The range of degrees in MicroStation V8i is 1 to 14. Therefore, the range of order is 2 to 15.

Control Points

The control points are a list of at least the number of the order. Therefore, a fourth order curve needs at least four control points to be defined.

One of easiest ways to change the shape of a NURBS curve is to move its control points.

The control points have an associated number called a weight. With a few exceptions, weights are positive numbers. When a curve’s control points all have the same weight (usually 1), the curve is called non‐rational, otherwise the curve is called rational. The R in NURBS stands for rational and indicates that a NURBS curve has the possibility of being rational. In practice, most NURBS curves are non‐rational. A few NURBS curves, circles and ellipses being notable examples, are always rational.

Knots

The knots are a list of degree+N‐1 numbers, where N is the number of control points. Sometimes this list of numbers is called the knot vector. In this term, the word vector does not mean 3‐D direction.

This list of knot numbers must satisfy several technical conditions. The standard way to ensure that the technical conditions are satisfied is to require the numbers to stay the same or get larger as you go down the list and to limit the number of duplicate values to no more than the degree. For example, for a degree 3 NURBS curve with 11 control points, the list of numbers 0,0,0,1,2,2,2,3,7,7,9,9,9 is a satisfactory list of knots. The list 0,0,0,1,2,2,2,2,7,7,9,9,9 is unacceptable because there are four 2s and four is larger than the degree.

The number of times a knot value is duplicated is called the knot’s multiplicity. In the preceding example of a satisfactory list of knots, the knot value 0 has multiplicity three, the knot value 1 has multiplicity one, the knot value 2 has multiplicity three, the knot value 3 has multiplicity one, the knot value 7 has multiplicity two, and the knot value 9 has multiplicity three. A knot value is said to be a full‐multiplicity knot if it is duplicated degree many times. In the example, the knot values 0, 2, and 9 have full multiplicity. A knot value that appears only


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once is called a simple knot. In the example, the knot values 1 and 3 are simple knots.

If a list of knots starts with a full multiplicity knot, is followed by simple knots, terminates with a full multiplicity knot, and the values are equally spaced, then the knots are called uniform. For example, if a degree 3 NURBS curve with 7 control points has knots 0,0,0,1,2,3,4,4,4, then the curve has uniform knots. The knots 0,0,0,1,2,5,6,6,6 are not uniform. Knots that are not uniform are called non‐uniform. The N and U in NURBS stand for non‐uniform and indicate that the knots in a NURBS curve are permitted to be non‐uniform.

Duplicate knot values in the middle of the knot list make a NURBS curve less smooth. At the extreme, a full multiplicity knot in the middle of the knot list means there is a place on the NURBS curve that can be bent into a sharp kink. For this reason, some designers like to add and remove knots and then adjust control points to make curves have smoother or kinkier shapes. Since the number of knots is equal to (N+degree‐1), where N is the number of control points, adding knots also adds control points and removing knots removes control points. Knots can be added without changing the shape of a NURBS curve. In general, removing knots will change the shape of a curve.

Knots and Control Points

A common misconception is that each knot is paired with a control point. This is true only for degree 1 NURBS (lines). For higher degree NURBS, there are groups of 2 x degree knots that correspond to groups of degree+1 control points. For example, suppose you have a degree 3 NURBS with 7 control points and knots 0,0,0,1,2,5,8,8,8. The first four control points are grouped with the first six knots. The second through fifth control points are grouped with the knots 0,0,1,2,5,8. The third through sixth control points are grouped with the knots 0,1,2,5,8,8. The last four control points are grouped with the last six knots.

Evaluation or Basis Rule

A curve evaluation or basis rule is a mathematical formula that takes a number and assigns a point.

The NURBS evaluation rule is a formula that involves the degree, control points, and knots. In the formula there are some things called B‐spline basis functions. The B and S in NURBS stand for basis spline. The number the evaluation rule starts with is called a parameter. You can think of the evaluation rule as a black box that


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eats a parameter and produces a point location. The degree, knots, and control points determine how the black box works.

For more detail, please refer to:

http://web.cs.wpi.edu/~matt/courses/cs563/talks/nurbs.html

http://devworld.apple.com/dev/techsupport/develop/issue25/schneider.html

B‐spline curves

B‐spline curves represent industry standard NURBS curves. NURBS stands for Non‐Uniform Rational Basis Spline. The B‐spline is defined by placing control points, or poles, with a minimum of 3 poles required.

The number of control points/poles must be greater than or equal to the Order of the equation. The Order of an equation is equal to the degree of an equation plus 1. The degree refers to the highest exponential term in the equation. Therefore, by using an order of 4 you are asking the software to use cubic equations to define your curvature.

The benefits of NURBS are many fold.

• NURBS do not have resolution. No matter how close to the surface or curve you are the surface or curve appears smooth, not faceted.

• NURBS allow for local controllability. Editing can be constrained to a point, or to a group of points on the surface of curve.

• There are several industry standard ways to exchange NURBS geometry. This means that customers can and should expect to be able to move their valuable geometric models between various modeling, rendering, animation, and engineering analysis programs. They can store geometric information in a way that will be usable 20 years from now.

• NURBS have a precise and well‐known definition. The mathematics and computer science of NURBS geometry is taught in most major universities. This means that specialty software vendors, engineering teams, industrial design firms, and animation houses that need to create custom software applications, can find trained programmers who are able to work with NURBS geometry.

• NURBS are computationally efficient. The amount of information storage required for a NURBS representation of a piece of geometry is much smaller


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than the amount of information storage required by common faceted approximations.

Accuracy

Because of the limitation of current computer technology, you expect calculations to be accurate to 15 digits of precision in a range from ±1020 to ±10‐20. This limitation is found in all modern CAD products.

Most CAD products do not even have tools to match curvature, let alone do it accurately enough for a discriminating designer. If your application requires smooth free‐form surfaces such as airfoils, hydrofoils, lenses, or reflective surfaces, complex roof structures you need these tools found in MicroStation V8i.

Curve types

The Create Curves tools can be found in any drawing task, so it is available in all 3D tasks. MicroStation can produce a large number of different curve types. Several tools are available to help you with standard curves such as spirals and helices. In addition, there are more advanced tools to generate a curve according to an equation using the Curve Calculator tool. The curves tools can be accessed from the Basic 3D task by selecting Q + 1 + 5.Tools from left to right are B‐spline by Points, B‐spline by Tangents, Composite Curve, Interpolation by Arcs, Conic Curve, Spiral Curve, and HelixCurve.


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Place B‐spline Curve tool

2D B‐spline curves, both open and closed, can be used as profiles to create complex 3D surfaces and solids. They can also be used as paths for the advanced extrusion tools that let you extrude a profile along a defined path. In this role, they may be either 2D (planar) or 3D.

B‐spline Surfaces generated from open and closed B‐spline curves

Appearance of a curve is controlled by the Order setting. The higher the order of an equation, the smoother the resulting curve. The Order is defined in the tool settings for some types of B‐splines. The minimum order possible is 2 and the maximum order allowed is 15.

You can also choose between Open and Closed B‐splines. When a B‐spline is closed, with the first point and the last point being the same, the enclosed area is a surface.

There are 5 methods used for creating B‐spline curves in MicroStation:

• Define Control Points

• Through Points

• L‐Square By Tol

• L‐Square By Num

• Catmull‐Rom

You can define a B‐spline curve by placing points or by applying the curve to an existing element in the design file. This is determined by the Input By setting, which lets you choose between the following.

• Enter Data Points, where you place each control point or pole.

• Pick Line String, which uses the vertices of a previously created construction element to define the poles. Line strings or complex chains produce open B‐splines. Shapes and complex shapes produce closed B‐splines.


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Exercise: Draw a 3D B‐spline curve


User: untitled


2 Open B‐spline_curves.dgn from the class data set.

3 Open the model 01_curves.

You will use arcs to draw a 3D B‐spline curve.

4 Open the B‐spline and 3D dialog by selecting Element > 3D and B‐spline and set the following:

Curve Polygon: Invisible

Curve Display: Visible

This dialog displays the default settings for B‐spline curves, Surfaces and Solids.

5 Close the 3D and B‐splines dialog.

6 Make the Surface Modeling tasks active in the Task Navigation dialog.

7 Select the Place B‐spline Curve tool (W + 1 + 1), with the following tool settings:

Method: Control Points

Input By: Points (AccuDraw)

Closure: Closed

Order: 4


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8 Following the status bar prompt, in the Isometric view, snap to the endpoint of the arc and accept with a data point.

9 Snap to the endpoint of the next arc and accept with a data point.

10 Snap to the midpoint of the second arc and accept with a data point.

After 3 points, the proposed curve displays as you move the pointer. You are drawing a fourth order curve, so a minimum of 4 points is required to


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define the curve. The control polygon, which appears as a dashed line, is also shown.

11 Snap to the end of the second arc, accept with a data point, snap to the end of the first arc, and then accept with a data point.


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12 Snap to, and accept, the midpoint of the first arc.


14 Fit each view.

Once a B‐spline curve has been placed, you can adjust various settings. For example, if you have drawn a fourth order B‐spline you can change the order of the curve. When you do this, it cannot be changed to an order that is higher than the number of points used to place the curve. You can check for point information using the Element Information tool, or enable polygon display, to show where the points are located.


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Exercise: Displaying the polygon and other curve information

1 Continuing in B‐spline_curves.dgn, in the model 01_curves, make the Surface Modeling tasks active in the Task Navigation dialog.

2 Select the Edit Control Points Settings tool (W + 3 + 1)

Select, Control Points On, in Tool Settings.

3 Identify the B‐spline curve and accept with a data point.

B‐spline control points display

This shows you where the control points, or poles, are located. You can also change the number of poles using this tool.

4 Select Change No. of Control Points in Tool Settings and change to 12

points.


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As the order of the B‐spline curve increases, more points are considered for calculating each part of the curve. This results in a smoother curve. With the smoothing, there is more variation between the polygon and the curve.

6 Change Number of control points back to six points.

7 Select, Control Points Off, in Tool Settings.

A second Order B‐spline curve (a line) fits the shape of the polygon exactly, while higher order curves vary from the polygon. You can use the Change Curve Order tool to change the order of the curve and see this for yourself.

Exercise: Change the order of the curve

1 Continuing in B‐spline_curves.dgn, in the model 01_curves, select Change Curve Order Settings tool (W+3+2) in Surface Modeling Tasks.

Order: Type in 2

Preserve shape: Disabled



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B‐spline with curve order set to 2

The following is the B‐spline created with the Preserve Curve Shape enabled.

The curve has an order of 2, but it would have retained its original shape.

3 Experiment further by changing the order of the curve between 2 and 6.

For this curve, which was constructed with 6 control points, sixth order is the highest allowed.

What you have drawn is a closed B‐spline curve, which creates a surface. Another option is to construct an open B‐spline curve.

Exercise: Creating a open B‐spline curve

1 Continuing in B‐spline_curves.dgn, open the model 02_curves.

2 Select Element > B‐spline and 3D to open the B‐spline and 3D dialog.

Curve Polygon display is set to Visible. This was set in the previous exercise when you enabled Polygon Display. This persists in the DGN, for the current session. Selecting File > Save Settings saves these settings for future design sessions.

3 Set the following:

Curve Polygon: Invisible

Curve Display: Visible

4 Close the dialog.

5 Select the Place B‐spline Curve tool (D + 1 + 1) with the following tool settings:

Method: Define Control Points

Input By: Pick Line String

Closure: Open

Order: 3


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6 In the Top view, select the line string and accept with a data point.

You can preview the curve before accepting it with another data point. Do not accept the curve yet.

7 Change the Order to 4, press Tab, and drag the pointer into the view to see the new curve.

8 Experiment with Order values between 2 and 15.


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9 Change the Method to Through Points and drag the pointer into a view to see this curve.

10 Experiment with the Methods Least Squares by Tolerance, Least Squares by Number and Catmull‐Rom.


Through Points is helpful when you want to send the curve through a series of points, for example to draw the edge of a road.

Catmull‐Rom adds additional poles on the curve to allow it to more closely represent the control polygon (the line string). This is helpful when you want to edit individual poles.

If you have an existing element in the design file, you can convert that to a B‐spline curve.

Place Composite Curve

Like the B‐Spline Curve tool, Place Composite Curve is another tool that creates complex chains and shapes.

Tool settings options for this tool let you select the type of curve and specify the curve radius and angle parameters for each segment during construction. The Mode tool setting option lets you select any of 4 element segment types.

• Arc by Edge: Transitions from a line segment into a tangent arc.


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• Arc by Center: Same transition as arc by edge, this mode identifies the center of the new tangent arc.

• Bezier Curve: Mathematically generated, free‐form curve used in design situations where the position of every point which forms the absolute curve line is critical (an airfoil).

• Line Segment: Constructs line strings generated by continuous data points.

There are other tool settings available.

• Smooth Corners: When enabled,permits smooth vs. sharp pointed corners when constructing arcs and Bezier curves.

• Planar: When enabled,the active design file is now 3D and the composite curve is forced to lie upon 1 of the planes.

• Arc Radius and Arc Angle: When enabled, permits value entries for pre‐setting the arc radius and sweep angle. These options only apply when using the arc by edge or arc by center curve segment mode.

In the following exercise, you will construct a composite curve shape representing the topographic contour line.

Exercise: Placing a contour line

1 Continuing in B‐spline_curves.dgn, open the model 03_Composite.

2 Make the Solids Modeling Tasks the active tasks in the Task Navigation dialog.

3 Select Place Composite Curve (Q + 3 + 3) with the following tool settings:

Method: Arcs by Edge

Smooth Corners: Enabled

All other options: Disabled

The status bar prompts you to enter the first vertex.


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4 Enter a data point at any magenta point.

5 Snap to, and enter a data point on, an adjacent point (clockwise or counter‐clockwise).

6 Select a third point, adjacent to the last point.

The arc is now visible and its end moves dynamically with the pointer.

7 Enter the end points for the next 8 arc segments by entering data points at the remaining points.

8 Change the following tool settings:

Method: Bezier Curves

9 Enter the last point and modify the tangency by moving the dynamic tangency handle.

The complex chain of elements automatically became a complex shape.

Optional Exercise: Change the tool settings


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1 Try the previous exercise again, except disable Smooth Corners in the Place Composite Curve tool settings.

Note the difference in the dynamic movement.

2 Experiment with the other composite curve modes by themselves, and in combination with each other.

The Place Composite Curve tool lets you place line segments and then transform them into a curve. With the Smooth Corners option selected, the curve is placed tangent to the line segment or place reversed tangent curves.

In the following exercise, you will create the line by connecting the straight line segments with reversed curves.

Exercise: Adding a road centerline

1 Continuing in B‐spline_curves.dgn, open the model 04_Composite.

2 Set the active attributes as follows:

Level: Center Line

Color: 0

Style: 4

Weight: 1

3 Select Place Composite Curve (Q + 3 + 3) with the following tool settings:

Method curve: Line Segments

Smooth Corners: Enabled

Planar: Disabled


4 Following the status bar prompt, working from left to right, enter the first vertex of the composite curve with a data point.


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5 Snap to the point to the right and enter a data point.

The curve (as a line segment) is now visible and the end moves dynamically with the pointer.

6 In the tool settings, change the Mode to Arc by Edge.

7 Snap to the point to the right and enter a data point.

The curve section begins tangent to the line segment.

8 Continue placing points, by snapping and accepting, points to the right.

The position of some locations forces a segment curve to form with an opposite sweep to the first. This is a reversed tangent curves. A reverse, or


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ogee, curve is created from two consecutive tangent arcs curve in opposite directions.


Place Composite Curve’s tangent curve feature can save time, especially in construction geometry applications.

Conic and Spiral Curve tools

There are several other curve tools available in MicroStation, 2 helpful ones are Conic sections or Spirals.

Place Conic

A planar section of a cone produce several types of curves; circle, ellipse, parabola, or hyperbola. When a plane intersects a cone on any angle from the


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base, the section is an ellipse. If sectional plane is parallel to base then a circle, if

parallel to sides of cone then a parabola and if the section is orthogonal to base then a hyperbola is created.

Rho is used to determine the shape of Ellipses, Hyperbolas and Parabolas

Place Spiral

Three types of basic spirals are Clothoid, Archimedes, and Logarithmic.


Linear Elements

Clothoid Spiral

The clothoid, or double, spiral is a curve whose curvature grows with the distance from the origin. The radius of curvature is opposite proportional to its arc, measured from the origin.

Clothoid Spiral with: Initial Degree: ‐1000, Final Degree: 1000, Length: 50

Archimedes Spiral

The Archimedes Spiral has constant pitch or distance between turns (1 turn is 1 convolution of the spiral).

Archimedes Spiral with: Initial Radius: 1, Final Radius: 16.1, Angle: 1800


Linear Elements

Logarithmic Spiral

The Logarithmic spiral has variable pitch convolutions. The distance between each turn of the spiral increases at a logarithmic rate, for example, 1, 10, 100, 1000, etc.

Logarithmic spiral with: Initial Radius: 1, Final Radius: 16.1, Angle: 1800

Place Helix tool

You can think of a helix as a spring. It is a 3D spiral that can be used for creating the basic shape of a screw, a spiral staircase, or coiled piping. Using the Place Helix tool is simple, and subtle variations let you create a wide variety of helices. The Place Helix tool is located in the Create Curves task. Tool settings are as follows.

• Thread: Specifies if the helix spirals to the right or left

• Axis: Determines the axis of the helix (you can define the axis interactively, or you can set it to either a design file axis or a view axis)

• Orthogonal: If on sets the axis of the helix perpendicular to the base and top

• Top Radius: Defines the radius at top of helix

• Bottom Radius: Defines the radius at bottom of helix

• Height: Defines the total height of helix

• Pitch: Defines the height of 1 revolution of the helix

• Tolerance: Sets the tolerance

Exercise: Creating a Helix


Linear Elements

1 Continuing in B‐spline_curves.dgn, open the model Helix.

2 Select Place Helix (S + 1 + 7) with the following tool settings:

Thread: Right

Axis: Points

Orthogonal: Enabled

3 Following the status bar prompt, snap to the bottom of the centerline and accept with a data point. You are prompted to define the radius.

4 Press <F> to rotate to the Front plane.

5 Move in the positive x‐ direction and, with the pointer indexed to the x‐axis, type 2 and accept with a data point.

You have defined the center point and Base Radius of the helix, and are now prompted to define the pitch height and axis.


Linear Elements

6 Move in the positive y‐ direction and with the pointer indexed to the y‐axis, type 3 and accept with a data point.

You now have defined the pitch of the helix and are prompted to define the height.

7 Snap to the top of the centerline and enter a data point to accept.

This sets the height of the helix, and you are now prompted to define the radius.

8 Move in the positive x‐ direction, type 2 and accept with a data point.


Challenge Exercise

Using the Place Helix tool is simple when you use AccuDraw. As with other tools, following the status bar prompts is the best way to proceed.

Challenge Exercise

Marine Design ‐ Hard Chine Hulls

The Planing Hull (hard chine) is a hull of any size, with either a single chine or an inner and outer chine. Inputs include values such as overall length and beam, as well as shape parameters.


Challenge Exercise

A is a S‐bottom hull, B is a Hard Chine hull. The term hard chine indicates an angle with little rounding.

A complete list of inputs could include:

• Bow ‐ Front of the boat

• Length Overall ‐ Overall Length of boat

• Beam Overall ‐ Width of boat

• Deck Height Forward ‐ Height from bottom to top at the front of the boat

• Deck Height Aft ‐ Height from bottom to top at the back of the boat

• Chine Height Forward. ‐ Height of the chine from bottom to the chine at the front.

• Chine Width (0=single chine, >0 gives inner and outer chine) ‐ Maximum chine width.

• Transom ‐ A surface that forms the flat stern on a hull. Dinghies tend to have almost vertical transoms, whereas yachts' transoms may be raked forward or aft.

• Deadrise angle ‐This is the angle from horizontal from which the hull rises up, measured at the transom, in deep or modified deep V hull forms or the measurement of the angle between the bottom of a boat and its widest beam.


Challenge Exercise

A vessel with a 0º deadrise has a flat bottom, high numbers indicate deep V shaped hulls. Shown below in red.

• Stem rake angle ‐ Forward pointing angle of the stern hull or transom.

There is no right answer in the following exercise. It lets you explore acceptable parameters of ship design. The model given shows graphically what the basic values are and some sample curves.

Some basic rules:

• Ratio of Length to Beam: 3 ‐ 3.5

• Ratio of Forward Deck Height to Length: 1 to 7

• Deadrise Angle ‐ Below 17 degrees is considered flat bottom or ski boat, 17‐21 degrees is modified deep V, and above 21 degrees is a deep V hull design.

Exercise: Explore ship design

1 Open the model Challenge_01.

2 A pre‐drawn sketch using B‐SPline by Points and Catmull‐Rom curves is started, using the following values for:

Length Overall: 7.16m

Deck Height Forward: 1.3m

Deck Height Aft: 1m

Maximum Beam: 2.2m.


Challenge Exercise

Aft Beam: 2m

3 Draw your own, by drawing the lines representing:

Length Overall ‐ 10m

Deck Height Fore ‐ 1.45m

Deck Height Aft ‐ 1.25m

Maximum Beam ‐ 3.3m

Aft Beam ‐ 3m

4 Then draw the curves using B‐Spline by Points, Method: Catmull‐Rom.

Reference Information:

• http://www.carlsondesign.com/hulls.zip

• FreeShip Design Software ‐ Can be imported into MicroStation

• http://groups.yahoo.com/group/bolger/

• http://www.wally.com

• http://www.pershing‐yacht.com

• http://www.tedbrewer.com/yachtdesign.html

• http://www.worldwideflood.com/ark/terms/ship_terms.htm

Drawing a Catenary

The catenary is the shape of a hanging flexible chain or cable when supported at its ends and acted upon by a uniform gravitational force (its own weight) and in equilibrium. The curve has a U shape that is a hyperbolic cosine curve. Catenaries are used to design Overhead Power Lines. Minimum ground clearance for roads is 16ft or 4.9m. Maximum sag of the cable is found from the span between poles, as a ratio.

Exercise: Draw catenaries

1 Open model Challenge_02.

2 From the Surface Task choose Curves > Curve Utilties > Curve by Formula (W+4+4).

3 From the File menu of the Curve by Formula dialog select Open File and select curve.rsc.

4 Select the Caternary Curve.


Module Review

5 In the dialog change the span (x1) to 50.

6 The Catenary is place from a Top view perspective, so switch to the Top view.

7 In the Curve by Formula dialog select Place.

8 Move the Caternary into place.

Reference Information:

• http://www.iaei.org/subscriber/magazine/othercode_Series/july_august1998.pdf

• http://www.energex.com.au/upload/technical_documents/20070130_151356_3750727.pdf

Module Review


Questions

1 How do you place a B‐spline curve using Through Points option?

2 True or False: By increasing nodes on a B‐spline curve you also increas the time to compute the results.

3 What tool would you use to modify a curve such that you create a sharp turn in the curve shape?

4 How do you select the back face on a 3D model?


Answers

1 A B‐spline is defined by placing control points, or poles, with a minimum of 3 poles required.

2 False. Increasing curve nodes using the Edit Nodes tool allows you to have more control over the curve shape. Another methos is the increase the order of the curve but this method requires more computation time.

3 The Edit Kink tool. This tool allows a very localized modification of a curve so that the handelbars of the kink can be modified to create sharp direction change in the curve.

4 When selecting a face within a tool sequence select a visible face then move the cursor to a common edge and select this edge using a tentative snap which will select the coincident face.


Basic 3D Solids

Module Overview

This module presents tools for Curves, Solids and Surfaces. When working with Solids it helps to think like a sculptor who starts out with a mass and cuts away what is not needed. Of course, in digital 3D you can add just as easily.


• Knowledge of 3D tools in MicroStation

• Knowledge of 2D Drawing tools in MicroStation


Module Objectives


• Use new 3D modification and creation workflows

• Use existing and new 3D Primitives

• Apply new features of existing tools

Feb-09 117 Basic 3D Solids





Questions

1 Name the AccuDraw shortcut used to cycle through rotations.

2 What 3D primitive lets you create a box‐shaped object?

3 What is Feature Modeling?

Answers

1 E.

This shortcut will cycle through all orthogonal rotations.

2 Place Slab.

3 Feature Modeling tools let you create parametric feature‐based solids. That is, a parametric solid that is created from one or more features. Each part of a solids model created with these tools is a feature. Parameters used to create the features are stored in the design and may be edited.

3D Workflows

All 3D modeling tools now have a unified workflow that covers that way that you select items for creation and modification, and how you can modify them interactively.

For example, you can now select edges and faces of solids and surfaces for modification with Element Selection. Typically, selecting edges, faces, or vertices, for solids and surfaces is as follows:

• Generally — select single items with a data point, and use Ctrl + data button for additional items.

• Faces — select the solid/surface first, and then dynamics let you select face(s).

• Back Faces — snap to an edge or vertex of a back face.

• Edges/Vertices — direct selection, or through dynamic selection.

Basic 3D Solids 118 Feb-09Copyright © 2009 Bentley Systems, Incorporated

3D Workflows

Interactive handles to control 3D objects during creation

Interactive handles let you control aspects of 3D objects during creation. For example, you can reverse the direction of surface normals interactively, during construction of fillets, by clicking the direction handles.

Solids Modeling

Contains basic Drawing tools plus 3D‐specific tools for creating primitive solids, extrusions, revolutions, converting solids to surfaces and vice versa, and the Draw on Solid and Modify Solid Entity tools.

The first tool in the Solids Modeling task, Place SmartLine initially, is also a member of the Drawing task. When you press the left mouse button over the tool, you see a drop‐down menu from which a tool in the Drawing task can be selected. The Drawing task can be opened as a floating toolbox by selecting Open As ToolBox from the drop‐down menu.

When a tool is selected in the Drawing task, the tool automatically becomes the top icon of the child task in the Solids Modeling task.

Hint: Press F4 to see the current tasks at the pointer.

Feb-09 119 Basic 3D SolidsCopyright © 2009 Bentley Systems, Incorporated

3D Workflows

Surface Modeling tasks

These tasks contain the Drawing toolbox, plus tasks for construction, and modification of surfaces and mesh elements.


3D Workflows

Feature Based Solids Modeling tasks

MicroStation has advanced solids modeling construction and modification tools for parametric modeling using Feature trees. These are contained in the Feature Based Solids Modeling task.


3D Primitive Solids

Alternate Display options exist for the Task Navigation dialog. Right click on the name of a task in the dialog itself or select an icon from the icons displayed aside of the Task name.

List option is useful when learning a new task and Panel option exposes all tools.

3D Primitive Solids

Many 3D solids can be created from 1 or more of the Primitive Solids models located in the Solids Modeling Task. The primitive models available include the Slab, Pyramid, Sphere, Cylinder, Cone, Elliptical Cone, Ellipsoid, Torus, Wedge, and Polyhedron.

3D Surface Primitives have been moved to the Surface Task.

Each tool setting has the Method, Axis and required parameters to create the specific Primitive Solids:

• Method: Creation by Vertex, Edge, Face, Inscribe, Circumscribed, Center, Edge, or Diameter.

• Axis: Lets you choose how the axis for the element is defined. You can select from Points (AccuDraw), Screen X, Y, or Z, or Drawing X, Y, or Z. Screen is direction of the height is set to the screen's X, Y, or Z axis. Drawing is direction of the height is set to the drawing's, or model's, X, Y, or Z axis


3D Primitive Solids

Other settings are specific for each tool.

Hint: Although the primitives’ dimensions can be specified in the tool settings, for placing a single primitive it is generally quicker to type these distances into the AccuDraw window.

Slab Solid

Probably the most useful of all primitives, the Place Slab tool can be used to draw any cubic object. Using this tool, you can construct a box shaped solid or surface. Element specific tool settings are as follows.

• Axis: Points (AccuDraw), Screen X, Y, Z, Drawing X, Y, Z

• Orthogonal: When enabled, the sides are perpendicular to the base.

• Length: If on, specifies the length.

• Width: If on, specifies the width.

• Height: If on, specifies the height.

Slabs placed as Solid (left) and Surface (right)

Place Sphere

With this tool, you can construct a sphere with 2 data points. Element specific tool settings are as follows.

• Method: Center, Edge, Diameter



3D Primitive Solids

• Radius: When on, specifies the Radius.

Place Cylinder

A cylinder is defined by 3 data points, the center of its radius, then the radius, and finally the height. Element specific tool settings are as follows.


• Orthogonal: If on, the centerline of the cylinder is perpendicular to the base.

• Radius: If on, specifies the radius.


Hint: You can use the Modify Element tool to reposition the base or top of cylinders.

Place Cone

Similar to the Place Cylinder tool, the Place Cone tool requires a fourth data point to define the Top radius of the cone. A cone with its apex cut off by a plane parallel to its base is called a truncated cone or frustum.

Element specific tool settings are as follows.


• Orthogonal: If on, the centerline of the cone is perpendicular to the base.

• Top Radius: If on, specifies the top radius.

• Base Radius: If on, specifies the base radius.



3D Primitive Solids

Place Torus

A torus is a round doughnut‐shaped object that is defined by 4 data points; the start point, the center point, the sweep angle, and the secondary radius. The primary radius is the one the torus is swept around and is the distance between the start point and the center point. The secondary radius defines the inner radius, or the radius of the torus’ circular section.



• Primary Radius: If on, specifies the primary radius.

• Secondary Radius: If on, specifies the secondary radius.

• Angle: If on, specifies the sweep angle.

Place Wedge

A wedge is constructed by revolving a rectangular section about an axis. It is defined by 4 data points. The first data point defines a corner of the wedge, the second data point defines the center point of the wedge and the point to rotate about, the third data point defines the sweep angle and the fourth data point defines the height of the wedge.



3D Primitive Solids


• Triangular: Determines the shape of the wedge. If on, the outer face is flat (a chord of the swept surface). If off, the outer face is rounded.

• Radius: If on, specifies the radius.

• Angle: If on, specifies the angle.


Place Pyramid Solid

A multi‐sided pyramid with equal sides or a rectangular pyramid can be created with this new primitive solid.

• Method: Inscribed, Circumscribes, By Edge, and Rectangle


• Orthogonal: When enabled, the sides are perpendicular to the base.

• Edges: You can create from 3 to 63 edges.

The image on left shows Inscribed, Circumscribed, By Edge method and image on right shows Rectangle method

A multi‐sided pyramid with equal sides or a rectangular pyramid can be created with this new primitive solid.

• Method: Inscribed, Circumscribes, By Edge, and Rectangle

• Axis: Points (AccuDraw), Screen X, Y, Z, Drawing X, Y, Z.

• Orthogonal: When enabled, makes the height perpendicular to the base.

Exercise: Draw a Pyramid Solid


3D Primitive Solids

1 Open Basic_Solids.dgn and open the model named 01_3D Primitives.

2 Make the Solids Modeling task active in the Task Navigation dialog.

3 Select Pyramid Solid (E+2) with the following tool settings:

Method: Inscribed

Axis: Points (AccuDraw)

Edges: 5

Orthogonal: Enabled

4 Enter Center Point: Click anywhere in view and set AccuDraw rotation to (T).

Define base radius: Move cursor 40 units in positive X direction.

Define height: Move cursor 80 units in positive Z direction.

Define top radius: Move cursor 20 units in positive X direction.

When Orthogonal is disabled, you can create skewed Pyramid Solids, where the sides and height are not restricted to being perpendicular to base radius.

When all settings are enabled, you merely define the direction of each dimension. This is useful when you want to place a number of Pyramid Solids with the same dimension values. If they are all identical, the Copy tool can be used after placing the first slab.


3D Primitive Solids

Elliptical Cone Solid

This tool is used to place an elliptical cone solid, which is a transition solid between two ellipses. The resulting solid is a SmartSolid. Tool settings are:


• Orthogonal: If on, the element is a right elliptical cone.

• Base Primary Radius: If on, sets the primary axis radius for the base.

• Base Secondary Radius: If on, sets the secondary axis radius for the base.

• Height: If on, sets the height of the elliptical cone.

• Top Primary Radius: If on, sets the primary axis radius for the top.

• Top Secondary Radius: If on, sets the secondary axis radius for the top.

Exercise: Draw a Elliptical Cone Solid using AccuDraw

1 Continuing in Basic_Solids.dgn, in the 01_3D Primitives model, with the Solids Modeling task active in the Task Navigation dialog, select Elliptical Cone Solid (E+6) with the following tool setting:


Orthogonal: Enabled

2 Enter a data point anywhere in view and set AccuDraw rotation to (T). Enter the base ellipse center point.

3 Enter a primary radius (x‐axis = 20) and a secondary radius (y‐axis = 40) to create the elliptical base.

4 Enter (z‐axis = 80) to define the height of the Elliptical Cone Solid.

AccuDraw automatically switches to the correct AccuDraw Plane rotation in order to enter the height.

5 Enter the primary radius (x‐axis = 40), secondary radius (y‐axis = 20) and final data point to complete the solid primitive.


3D Primitive Solids

Ellipsoid Solid

This tool is used to place an ellipsoid, a solid defined by three radii. An ellipsoid is a type of quadric surface that is a higher dimensional analogue of an ellipse.

Exercise: Draw an Ellipsoid Primitive Solid using AccuDraw

1 Continuing in Basic_Solids.dgn, in the 01_3D Primitives model, with the Solids Modeling task active in the Task Navigation dialog, select Ellipsoid Primitive Solid (E+7) with the following tool setting:


Orthogonal: Enabled

2 Enter a data point anywhere in the view and set AccuDraw rotation to (T). Enter the base ellipse primary radius (x‐axis = 40).

3 Enter a secondary radius (y‐axis = 20) to create the elliptical base.

4 Enter a tertiary radius (z‐axis = 20).to complete the Ellipsoid primitive solid.

AccuDraw automatically switches to the correct AccuDraw Plane rotation in order to enter the tertiary radius.

5 Enter the primary radius (x‐axis = 40), secondary radius (y‐axis = 20) and final data point to complete the solid primitive.

Regular Polyhedron

A polyhedron (plural polyhedra or polyhedrons) is often defined as a geometric object with flat faces and straight edges of equal length.

Method:

• Vertex — Radius is measured from the center of the polyhedron to each vertex.


3D Primitive Solids

• Edge — Radius is measured from the center of the polyhedron to the midpoint of each edge.

• Face — Radius is measured from the center of the polyhedron to the center of each face.

Radius: If on, defines the Radius used to construct the polyhedron.

Face Number: Option menu that lets you select the number of faces for the polyhedron — 4, 6, 8, 12, or 20.

Exercise: Draw an Polyhedron Primitive Solid using AccuDraw

1 Continuing in Basic_Solids.dgn, in the 01_3D Primitives model, with the Solids Modeling task active in the Task Navigation dialog, select Polyhedron (E+10) Primitive Solid with the following tool setting:

Method: Vertex


Face Number: 20

2 Enter a data point anywhere in view, set the AccuDraw rotation to (T), and then define the radius and axis for the Polyhedron primitive.


Create Solids Toolbox


The Create Solids Tools include Solid by Extrusion, Solid by Revolution, Solid by Extrusion Along, Solid by Thicken Surface and Linear Solid.

If you need to create complex or curved solids, you can often create them from a profile element. You can extrude a profile in a straight line, along a specific 3D path with profile rotation control.

Solid By Extrusion

This tool is used to construct 3D solids or surfaces from 2D profiles. It lets you extrude, or project, a planar 2D element along an axis to create a 3D object. Thus, lines become planes, circles become cylinders and blocks become slabs. When complex shapes or SmartLines are used as the profiles, quite complex solids or surfaces are possible. Available element types for extrusion are:

• Line

• Line string

• Arc

• Ellipse

• Shape

• Text

• Multi‐line

• Complex chain



• Complex shape

• B‐spline curve

Surfaces formed between the original profile element and its extrusion are indicated by straight lines connecting the keypoints.

Tool settings are as follows.

• Type: Solid or Surface.

• Orthogonal: When on, the sides are perpendicular to the plane of the profile element.

• Distance: When on, defines the distance of the projected extrusion.

• Spin Angle: When on, defines the angle through which the 2D element rotates (counter‐clockwise) about the axis of projection (maximum 360°). To correctly specify the rotation, you must select the shape at the point about which the rotation is to occur.

Hint: When using Spin Angle it is best to select the center of the profile as the pivot point.

• X Scale and Y Scale: When on, specifies the scaling factor for the shape as it is being projected. Scaling is uniform about the point at which the shape is identified.

• Both Directions: When on, the extrusion is constructed in both directions from the profile.

• Use Active Attributes: When on, the surface or solid of revolution is created with the element using the active attributes. When off, the surface or solid of revolution is created with the element taking the attributes of the profile element.

• Keep Profile: When on, the original profile element is kept. When off, the profile is deleted.

Exercise: Extruding a profile

1 Open Basic_Solids.dgn.

2 Open the model 02_Extrude 1.

The model is part of an observation platform. Profiles for the support columns are ready to be extruded.

3 Select Solid by Extrusion (R+1), with the following tool settings:

Orthogonal: Enabled



Distance: Enabled and set to 3.0


4 Following the status bar prompt, in the Isometric view, identify profile number 1.

5 Move the pointer above the profile so the extrusion is upward, and accept with a data point.

You can extrude multiple profiles, in a single operation, by first selecting the profiles with the Element Selection tool.

Exercise: Extruding multiple profiles

1 Continuing Basic_solids.dgn, in the model Extrude 1, select Element Selection (1) from the Main toolbox with mode set to Block and method set to Add.

2 In the Isometric view, draw a block around the remaining 3 column profiles.

3 Select Solid by Extrusion (R+1) with the following tool settings:

Orthogonal: Enabled

Distance: 3.00

4 All other settings: Disabled

5 Enter a data point to accept the selection set.



6 Move the pointer above the profiles so that the extrusion is upwards, snap to accept this direction.

Extrusions may have a scale applied to them, or a spin angle, or both.

Exercise: Extruding with Spin Angle and Scaling

1 Continuing in Basic_Solids.dgn, open the model 03_Extrude 2.

2 Select Solid by Extrusion (R+1), with the following tool settings:

Orthogonal: Enabled

Distance: Enabled and set to 8

Spin Angle: Enabled and set to 45

All other settings: Disabled

3 In the Isometric view, snap to the center of the left profile.



4 Move the pointer upward and accept with a data point.


Spin Angle: Disabled

X Scale: Enabled and set to 0.75

Y Scale: Enabled and set to 0.75

6 Identify the center of the center profile.



7 Move the pointer upward to extrude in that direction and accept with a data point.

8 Enable Spin Angle and set it to 45.

9 Identify the center of the right profile and extrude it upward.

With Orthogonal enabled, all extrusions are perpendicular to the plane of the element being extruded. The position of the pointer merely defines whether the projection is up or down from the profile. If you disabled Orthogonal, you can define the extrusion to be in any direction.

Solid By Revolution

When you require a curved circular extrusion, you can use the Construct Revolution tool. As with the Extrude tool, this tool also is used to construct 3D solids or surfaces from 2D profiles. In effect, a profile is revolved about an axis to create a solid or surface. Available element types for curved circular extrusion are:

• Line



• Line string

• Arc

• Ellipse

• Shape

• Complex chain

• Complex shape


Tool settings for this tool are as follows.

• Type: Solid or Surface.

• Axis: Defines the direction of the axis about which the revolution is performed. Options are: Points (AccuDraw); Screen X, Y, or Z; Drawing X, Y, or Z.

• Angle: Defines the sweep angle of the revolution (about the axis).

• Use Active Attributes: When on, the surface or solid of revolution is created with the element using the active attributes. When off, the surface or solid of revolution is created with the element taking the attributes of the profile element.

• Keep Profile: When on, the original profile element is kept. When off, the profile is deleted.

In the next exercise, you will rotate a profile of a rocket nozzle 360 degrees around an axis to create a solid.

Exercise: Create a solid by revolving a profile

1 Continuing in Basic_Solids.dgn, open the model 04_Revolution 1.

2 Select Solid by Revolution (R+2) with the following tool settings:


Angle: 360

Other settings: Disabled

3 In the Isometric view, identify the profile.



4 Snap to the top of the dash‐dot line at and accept with a data point.

The proposed solid is displayed. Note that the pointer now controls the axis of the revolution. As you move it the radius changes and the solid changes in size. You can change the axis plane using AccuDraw shortcuts.

The pointer controls the location of the axis.



5 Snap to the bottom of the dash‐dot line at and accept with a data point.

The solid is completed.

6 In View 4, click the View Display Mode view control and change the display mode to Smooth.

You can turn off the level Default to remove the centerline.


Using the Construct Revolution tool, you can create complex curved 3D solids from a 2D shape or complex shape. Equally, you can revolve an open element, such as a line string or an arc to create a curved surface.

Solid By Thicken Surface

This tool is used to add thickness to an existing surface to create a solid. Upon identifying the surface, an arrow displays showing the distance and direction of the thickening that will be added. If Add To Both Sides is on, arrows display in both directions. If Thickness is not turned on, then thickening is added graphically, with the amount of thickening defined by the screen pointer. Tool settings are:

• Add To Both Sides: If on, the thickness value is added to both sides of the surface.

• Thickness: If on, sets the thickness value that is added to the surface.

• Face Only: If on, lets you select an individual face of a solid or surface.



• Full Dynamics: If on, displays a preview. On large surfaces, the display may take a long time. Turning the toggle off will reduce the generation time.

• Keep Original: If on, the original profile element is retained.

How to use Solid By Thicken Surface:

1. Select the Solid by Thicken Surface tool.

2. Turn on Thickness.

3. In the Thickness field, enter the value for the thickening.

4. If necessary, turn on Add To Both Sides.

5. Identify the surface.

6. The surface highlights. An arrow(s) displays, showing the distance and to which side(s) the thickness will be added.

7. If Add To Both Sides is off, move the pointer, using the arrows as a guide, to select the side for thickening.

8. Accept.

Linear Solid

This tool is used to create a wall like solid (with rectangular section) by defining its alignment direction.

Exercise: Linear Solid

1 Continuing in Basic_Solids.dgn, open the model 05_Linear Solid.


3 Select Linear Solid (R + 5) with the following tool settings:

Place by: Center

Width: .5



Height: 3

4 Enter a data point in any view and draw the floor plan as dimensioned in the following image.


Challenge Exercises

Exercise: Draw a door and hardware

1 Create a new model in AccuDraw_3D.dgn. Set working units set to “m” (MU) and “cm” (SU) and work only in the Isometric view.

2 Use the Place Slab tool to create the solid door, 2.5m tall, 5cm thick and 75cm wide (Front orientation).

3 Place 2.5cm diameter cylinders for the hinges (7.5cm long starting 15cm from the top and bottom) with the center of the hinge on the edge of the door.

4 Use the Place Sphere and Place Cylinder tools to create the doorknob (5cm diameter spheres on both sides with a 2.5cm diameter cylinder, 15cm long, connecting them). Place the doorknob assembly 5cm from the edge of the midpoint of the door.

Exercise: Draw a floor lamp

The lip around the shade is a torus with a primary radius

of 30cm and secondary radius of 2.5cm. It is placed from

an edge of the shade.

The Shade is a surface Cone with a Base radius of 5cm, height of 22.5cmand Top radius of 30cm.

The Pole is a Cylinder that is 195cm high and 5cm in diameter.

The Base is Cylinder with a radius of 22.5cm and height of 5cm.


Module Review

Module Review


Questions

1 How do you place a B‐spline curve using Through Points option?

2 True or False: By increasing nodes on a B‐spline curve you also increase the time to compute the results.

3 What tool would you use to modify a curve such that you create a sharp turn in the curve shape?

4 How do you select the back face on a 3D model?

5 True or False. The new Polyhedron Primitive solid has an unlimited number of faces option.

Answers


2 False. Increasing curve nodes using the Edit Nodes tool allows you to have more control over the curve shape. Another method is to increase the order of the curve, but this method requires more computation time.

3 The Edit Kink tool. This tool allows a very localized modification of a curve so that the handelbars of the kink can be modified to create sharp direction change in the curve.

4 When selecting a face within a tool sequence select a visible face then move the cursor to a common edge and select this edge using a tentative snap, which will select the coincident face.

5 The Polyhedron Primitive Solid is limited to 4, 6, 8, 12, and 20 faces.


Module Review


Advanced Solid Modeling

Module Overview

Complex solids can be created by using additional tools for solid creation and modification.

Starting with basic solids or surfaces, you can add finishing touches such as fillets and chamfers. You can use a planar closed shape or open element as a profile to create a cut out in either a surface or a solid. Use the Shell Solid tool to create a hollow solid with defined wall thickness. You can also execute Boolean operation on Solids.



• Knowledge of Solid Primitives

Module Objectives


• Use and apply the Solid Construction tools

• Use and apply the Solid Modification tools

• Modify a face, edge, or vertex, of a solid

• Remove one or more faces from a solid

• Taper the face of a solid

• Construct a solid from the union, intersection or difference of 2 or more solids

• Place a cut in a solid

Feb-09 145 Advanced Solid Modeling



• Fillet or chamfer the edge(s) of a solid

• Edit 3D primitives



Questions

1 How do you place a B‐spline?

2 True or False: When you change the order of a curve it can be changed to an order that is higher than the number of points used to place the curve.


Answers


2 False. It cannot be changed to an order that is higher than the number of points used to place the curve.


Working Area

Solids modeling requires greater accuracy than that required for surface modeling. The Solids setting in the Working Areas section of the DGN File Settings dialog’s Advanced Unit Settings dialog (Settings > Design File, Working Units category) lets you set a working area that determines the degree of accuracy for solids calculations.

The Parasolid solid modeling kernels used by MicroStation require coordinate data at a fixed precision. In order to guarantee enough precision is available, MicroStation defines the solids working area.

Advanced Solid Modeling 146 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Working Area

The size of the solids modeling area can be increased, but doing so will reduce the available precision. It defines an upper bound that limits the extents of any single solid so that it can be modeled to a fixed precision. This precision value is displayed in the Advanced Unit Settings dialog as Solids Accuracy.

The settings that you use depend on whether you require compatibility with V7 projects or not. For best results, in the Resolution section, set storage unit to Meter. In the Working Areas (each axis) Solids section, for V8 projects Input 1 (Kilometer) and for V7 projects Input 0.

For V8 projects, this will set the Solids Accuracy to 1E‐008, which also is the Parasolids default. If you then make any changes to the Resolution setting, changing the Solids value back to 1 Kilometer will restore the Solids Accuracy to 1E‐008.

Feb-09 147 Advanced Solid ModelingCopyright © 2009 Bentley Systems, Incorporated

Solids Modeling Task

Solids Modeling Task

The Solids Modeling task contains the tools for construction and modification.

Panel view of the Solids Modeling task

Create Solids, Modify Solids, and Solid Utility tools

Solid By Extrusion Along

The Solid By Extrusion Along tool is used to construct 3D solids from 2D profiles extruded along a curve called a path. It replaces the Extrude Along Path tool.

You can create solids by extruding profiles along a path element that the profile element is to follow as it is extruded. When using a profile, you can specify that the extrusion is attached to the path element, or that it uses the path element to define the direction of the extrusion from the current location of the profile.

This tool can be used to create items such as roofs, pipe work, ductwork, or handrails. You can create the extrusion with a profile or by specifying the outside and the inside radii, where a circular solid or a hollow pipe is being constructed.



When Circular is selected for extrusions, the ends are capped.

The profile rotation can be determined by the curve geometry or the profile may be locked in a specific direction. This tool also permits self intersecting geometry, but when this condition exists, time for creation is slower.

For those that have used prior versions you will notice the absence of the Path to Profile and Profile to Path Attachment options which are no longer available in the MicroStation V8i version. After selecting a profile, you have a small ball that is the Change Start Point. This point can be dragged to modify the start of the path, giving you the same functionality as previous versions for Path to Profile or Profile to Path.

Available element types for extrusion are:

• Ellipse

• Shape

• Text

• Multi‐line

• Complex chain

• Complex shape


Open elements are not valid, as they would produce a Surface. If you need an open element, use the Surface by Extrusion Along command, from the Surface task.

Tool settings are as follows:

Alignment: Determines the orientation of the profile element as it is extruded.



• Normal — As the profile is extruded, it maintains a fixed relationship with the normal plane of the path.

• Parallel — As the profile element is extruded, it remains aligned parallel to its original position.

Scale: When enabled, and value is entered you are prompted to enter the scale point, the point that the result is scaled about.

Spin: When on, defines the angle through which the 2D element rotates (counter‐clockwise) about the axis of projection (maximum 360°).

Hint: When using Spin Angle it is best to select the center of the profile as the pivot point.

Lock Profile Rotation: When you need to keep the end profile in the same position as the start profile enable the Lock Profile Rotation option. Here



you select the path, profile or face, and then you must select the start of the lock direction and the end point of the locked direction.

Profile on left created with Lock Profile Rotation disabled and on right with Lock Profile Rotation enabled

This direction is an up vector indicating the position in a Cartesian coordinate system.

The up vector, which determines the rotation direction start and end point for a Locked Profile Rotation

Circular: When this option is enabled a profile is not necessary to complete construction. You must also enter an inside and outside radius to complete construction.

Solid By Extrusion Along with Circular option. On Left path and on right results with inside and outside diameters.



Allow Self‐Intersection: If the curvature of the path is too small for the profile to be swept through the path due to a self intersection of the profile then you can Enable Allow Self‐Intersection.

Keep Path: When on, the original path element is kept. When off, the path is deleted.

Keep Profile: When on, the original profile element is kept. When off, the profile is deleted.

Exercise: Solid By Extrusion Along with Lock Profile Rotation

1 Open Advanced_Solids.dgn, in the 01_Extrusion model, with the Solids Modeling task active in the Task Navigation dialog,

2 Select Solid By Extrusion Along (R + 3) with the following tool settings:

Alignment: Normal

Enable: Lock Profile Rotation

All others default.

3 Select the helical path at the start point and then snap to the middle bottom of the profile where it intersects the helical path, then accept the profile.



4 Place the start point of the lock direction at the bottom of the path and

the end point of the locked direction (up vector) in the direction of the axis of the path.

5 Accept with a data point.

Exercise: Solid By Extrusion Along with Spin Angle

1 Continue in Advanced_Solids.dgn, open the model 02_Extrusion.

2 Make the Solids Modeling task active in the Task Navigation dialog. You will create one of the cutting blades pictured in the image below.

3 Select Solid By Extrusion Along (R + 3) with the following tool settings:

Alignment: Normal

Enable Spin: Set angle to 60 degrees.

4 Select the straight line for the path and the closed shape for the profile

5 Select path and profile.




You will now use this tool to create a pipe.

Exercise: Extrude pipe

1 Continuing in Advanced_Solids.dgn, open the model 03_Extrude Pipe.


3 Select Solid by Extrusion Along (R + 3) with the following tool settings:

Circular: Enabled

Inside Radius: Enabled and set to 140

Outside Radius: Enabled and set to 143

4 In the Isometric view, identify the dashed path element with a data point anywhere along its length.

5 Accept with a data point to view the construction.

Depending on system specifications, this may take a few seconds.

The proposed pipe is calculated and displayed.

6 Accept the construction with a second data point.

The circular pipe extruded along the path element.

When using a profile as the template for the extrusion, you can create the extrusion directly from the position of the profile element, offset from the path element, or create the extrusion by attaching the profile to the path element.

Exercise: Create an extrusion offset from the path element

1 Continuing in Advanced_Solids.dgn, open the model 04_Extrude Duct.

2 Select Solid by Extrusion Along (R + 3), with the following tool settings:



Alignment: Normal

All others: Disabled

3 Identify the lower dashed path element with a data point, anywhere along its length.

4 Identify the square green profile and accept with a data point to see the construction.

5 Accept with a data point, to view the extrusion.

The proposed extrusion is calculated and displayed.

6 Identify the upper dashed path element with a data point, anywhere along its length.

7 Identify the arc green profile at one of its end points and accept with a data point to see the construction.



8 Accept the construction with a data point.

9 Fit View to see the offset extrusion in each view.

Remember, where required, you can specify that the extrusion is attached to the path element. You do this by moving the, at the point on it that you want attached to the path element.

Exercise: Create an extrusion attached to the path element

1 Continuing in Advanced_Solids.dgn, open the model 05_Extrude Handrails.

2 Select Solid by Extrusion Along (R + 3) with the following tool setting:

Alignment: Normal

3 Identify the green path element with a data point, anywhere along its length.

4 In View 2, select the left red profile element.


6 Enter a data point to view the proposed extrusion.


8 Repeat this procedure to construct a handrail along the yellow path, using View 3 to snap to the right red profile.



9 Use the view controls tools, such as Rotate and Zoom In/Out, to inspect the construction.

After extruding the handrails

Observing the other views, you can verify that the extrusion follows the alignment of the path element exactly.

Extra Exercise: Extruding a road cross section

1 Continuing in Advanced_Solids.dgn, open the model EXTRA_Extrude Bridge.

2 Use the Bridge Cross section and center, cyan, path element to create the bridge.

3 Use the 3 Guard Rail cross sections and the cyan path elements to create the guard rails.



Shell Solid tool

You can use the Shell Solid tool to hollow out a solid, leaving it with walls of a defined thickness. Where necessary, you can specify that 1 or more faces are removed to create an opening. Tool settings for this tool are as follows.

• Shell Thickness: Sets the wall thickness for the remaining faces of the shelled solid.

• Shell Outward: If on, material is added to the outside of the existing solid. The existing solid defines the inside of the walls of the shelled solid.

Selecting/deselecting faces for removal

After selecting the solid for shelling, as you move the pointer over it, the face nearest the pointer highlights. Entering a data point selects the dashed highlighted face, which then remains highlighted. To select additional faces, hold down the Ctrl key and move the pointer over the solid to highlight the face. You then can use Ctrl data points to select additional faces for removal.

To select a face that is behind another face in the view, enter a data point, or Ctrl data point, on the face, which will highlight the nearest face. Then reset until the required face highlights.

Resetting also can be used to deselect the last face selected. Subsequent resets deselect faces in the reverse order. The last face selected is the first face deselected.

In the following exercises, you will create shelled solids both with and without openings.

Exercise: Create a shelled solid with no openings

1 Continuing in Advanced_Solids.dgn, open the model 06_Shell 1.

2 Select Shell Solid (T + 5) with the following tool settings:

Shell Thickness: 15

Shell Outward: Disabled

3 In any view, identify the green solid.

The solid highlights. As you move the pointer over the solid, the various faces highlight in a heavier weight dashed line.

4 Move the pointer away from the solid, so that no faces are highlighted, and enter a data point.



5 Click on View Display Mode and select:

Mode: Hidden Line

The solid is hollowed out. As there are no openings, rendering the view would display only the outside surface.

6 Select Edit > Undo.

Exercise: Create a shelled solid with the top and front face removed

1 Continuing in Advanced_Solids.dgn, in the model 06_Shell 1, select Shell Solid (T + 5) with the following tool settings:

Shell Thickness: 15


2 In the Isometric view, identify the green solid with a data point.

3 Move the pointer over the solid until the top face highlights, and then enter a data point.

The top face now is highlighted as a heavier weight solid line.

4 Press Ctrl and select the front face.




The solid is shelled and the top face removed.

6 Set View 4’s View Display Mode to Smooth and use the view controls tools, such as Rotate and Zoom In/Out, to inspect the construction.

You can use any view to highlight the faces. For example, if you move the pointer into the Top view, the top face is nearest the pointer and is selected immediately. Generally, a rotated view, such as the Isometric, is easier to use because you can see exactly which surface is highlighted. Additional surfaces can be added by using the Ctrl key and accepting with a data point.

If a solid has rounding and/or one or more holes through it, the Shell Solid tool recognizes these and shells around them accordingly.

Warning: If the rounding radius is smaller than the offset radius, it cannot be offset and will not shell.

Exercise: Shell a solid containing rounding and holes

1 Continuing in Advanced_Solids.dgn, open the model 07_Shell 2.

2 Select Shell Solid (T + 5) with the following tool settings:

Shell Thickness: 5


3 Identify the green solid with a data point.



4 Move the pointer over the solid until the top surface highlights, and then enter a data point.

The top surface of the solid highlighted.

5 Accept with a data point to complete the shelling.

The solid after shelling and removing the top surface

6 Set View 4’s View Display Mode to Smooth and use the view controls tools, such as Rotate and Zoom In/Out, to inspect the construction.

Using the Shell Solid tool can save you considerable modeling time, particularly when the design has uniform thickness walls, as in the previous example.

Working in the opposite direction, you can create solids from surface elements. Earlier, you used the Extrude tool to create a solid from a planar surface. If the existing surface is not planar, however, the extrude tool will not work. In these cases, you can use Solid by Thicken Surface.



Solid by Thicken Surface tool

You can use the Solid by Thicken Surface tool to add thickness to an existing planar or non‐planar surface, thus creating a solid. Upon identifying the surface, an arrow displays showing the distance and direction of the thickening to be added. If Add To Both Sides is on, arrows display in both directions.

If Thickness is not turned on, then thickening is added graphically, with the amount of thickening defined by the cursor. If Add To Both Sides is off in these cases then the screen pointer also defines the direction of the thickening. Tool settings are as follows.

• Add To Both Sides: If on, the thickness value is added to both sides of the surface.

• Thickness: If on, the value in the field determines the amount of thickening added.

• Face Only: If on, lets you select an individual face of a solid or surface.

• Full Dynamics: If on, displays a preview. On large surfaces, display may take a long time. Turning the toggle off will reduce the generation time.

• Keep Original: If on, the original surface is retained.

In the following exercise, you will extrude a line string and then thicken it to create a section of office partitioning.

Warning: Thickness may be too large to permit the solid surface to be offset, since the solid would overlap itself. This tool does not allow for self‐intersection.

Exercise: Draw a shape and add thickness

1 Continuing in Advanced_Solids.dgn, open the model 08_Office.

This model has 2 office cubicles, with a line string showing the centerline for the proposed partitioning.

2 Select Surface by Extrusion (Surface Task, T+ 1), with the following tool settings:

Orthogonal: Enabled


3 In any view, select the red line string and accept with a data point.

4 Move the pointer upward to direct the extrusion upward, and accept with a data point.

5 Select Thicken to Solid (Solids Task, R + 4) with the following tool settings:



Add To Both Sides: Enabled

Thickness: Enabled and set to 25

6 Select the extruded line and accept with a data point.

The shape highlights and arrows appear, showing the direction and size of the thickening. Because you are adding thickness to both sides of the surface, you don’t have to worry about the direction of the thickening.

7 Select a Face and Ctrl+Data to select the other faces, accept again, to complete the thickening.

Hidden Line view of model after thickening the extrusion


Boolean tools

Replace Face

The Replace Face tool lets you replace a face of a solid with a selected surface. The result is a solid that has the selected surface as one of its faces.

How to use Replace Face:

Select the Replace Face tool. Identify the solid. Select the face to be replaced. Identify the surface and the face of the surface to be used as a replacement face, if necessary, and accept.

Boolean tools

Three tools in the 3D Modify toolbox let you unite, intersect, or subtract solids. They let you create a complex solid from two or more existing solids.

Unite Solid tool

With the Unite Solids tool, you can unite, into a single solid, two or more overlapping solids or solids that have coincident faces. This is very useful for grouping several separate solids into a solid, from which the finished model can be produced.


Boolean tools

In the tool settings, Keep Originals lets you choose to retain in the model the First, Last, All, or None.

• All: All of the original solids are retained.

• First: The first solid identified is retained.

• Last: The last solid identified is retained.

• None: None of the original solids are retained.

When constructing a union of solids, you can use the Element Selection tool to select the solids first, or select the tool first, then the solids.

When you use the first method, the color of the resulting solid is that of the (selected) solid that was placed in the file first. When you use the second method, the color of the resulting solid is that of the first solid selected.

As with the other exercises, you will work in the Isometric view which displays two copies of a simple window frame, each created from eight slabs.

Exercise: Construct the union of solids using Element Selection

1 Continuing in Advanced_Solids.dgn, open the model 09_Unite Solid.


You will consolidate these individual solids into a single entity. First, you will select the solids using Element Selection.

3 Select the Element Selection tool (1) with the following tool settings:

Method: Block

Mode: New

4 In the Isometric, Top, or Front view, place the block around all elements that make up the window on the left.


Boolean tools

The selected solids highlight.

5 Select Unite Solid (T + 7) with Keep Originals set to None.

6 Enter a data point to accept the union.

The separate solids are united into a single solid. The resulting solid (left) is red because one of the red slabs was placed in the model before the other slabs.

When you select the solids individually, the color of the first solid selected is the color that is used for the combined solid.

Exercise: Construct the union of solids, selecting each solid separately

1 Continuing in Advanced_Solids.dgn, in the model 09_Unite Solid, with the Unite Solid tool still active, identify one of the green frame members in the window on the right with a data point.

The slab highlights.

2 Identify the remaining slabs that make up the window with data points so that all are highlighted.

3 Enter a data point to accept the construction.

The solids are united into a single green solid.

If you happen to miss one or more of the solids, you can repeat the process, adding the solids that were left out, remembering that the first solid chosen defines the color of the united solid.


Boolean tools

Intersect Solids tool

Using the Intersect Solids tool, you can create a solid of a common volume of two or more overlapping solids.

In the tool settings, the Keep Originals setting lets you choose to retain in the model the First, Last, All, or None of the original solids.

When constructing an intersection of solids, you can select the solids first, followed by the tool, or you can select the tool first, then the solids.

When you use the first method, the color of the resulting solid is that of the (selected) solid that was placed in the model first. When you use the second method, the color of the resulting solid is that of the first solid selected.

Where you have 2D elevations of a design, often you will be able to use them to create extrusions of each elevation. From there you can use the Intersect Solids tool to create the finished solid.

In the following exercise, you will construct a 3D chair from the intersection of extrusions created from its front and side views.

Exercise: Create a solid from the intersection of 2 existing solids


Boolean tools

1 Continuing in Advanced_Solids.dgn, open the model 10_Intersection.

You see 2 sectional views of the chair. First, you will extrude these sections.

2 Select Solid by Extrusion (R + 1) with the following tool settings:

Orthogonal: Enabled



3 In the Top view, identify the green shape and extrude it to the right.

4 Repeat the previous step for the violet shape, extruding it upward.

5 Select Intersect Solids (T + 8) with Keep Originals set to None.

6 Identify the green and violet solids with data points, in any view.


Boolean tools

7 Enter a data point to complete the construction.

The resulting solid is green because the green solid was the first chosen.

Smooth shaded view of the completed chair.

Subtract Solids tool

With the Subtract Solids tool, you can subtract from a solid the volume of one or more overlapping solids. Additionally, you can subtract a part of a solid back to an intersecting surface.

As with the other boolean tools, the tool setting Keep Originals lets you choose to retain in the model the First, Last, All, or None of the original solids.

Exercise: Construct the difference between solids

1 Continuing in Advanced_Solids.dgn, open the model 11_Difference 1.

A green cone with a blue cylinder overlapping it is displayed.

2 Select Subtract Solids (T + 9) with Keep Originals set to None.

3 With a data point, identify the green solid.

4 With a data point, identify the blue cylinder.

The blue cylinder highlights.


Boolean tools

5 Enter a data point to complete the construction.

Before (left) and after (right) subtracting the blue cylinder from the green solid.

If you want to subtract several solids, you can select them all prior to accepting.

6 Turn on the level Tap Cutouts in the Isometric view.

Additional red cylinders now display.

7 Select Subtract Solids (T + 9) with Keep Originals set to None.


9 Identify each of the red cylinders in turn, so that they are all highlighted.

10 Enter a data point to complete the subtraction.


Boolean tools

If multiple solids are to be subtracted, it is often quicker to use the Element Selection tool to select them all prior to selecting the Subtract Solids tool.

You can use the same tool to subtract part of a solid back to where a surface intersects it. This can be useful for creating solid ground surfaces.

In the following exercise, you will subtract part of a slab back to a B‐spline surface representing the existing ground for a construction project. For this kind of construction, the part of the solid that is retained is defined by the surface normals of the surface element.

You can check the direction of the surface normals and, if necessary, reverse them with the Change Normal Direction tool.

Exercise: Subtract a solid back to a surface

1 Continuing in Advanced_Solids.dgn, open the model 12_Difference 2.

The model contains a slab and a B‐spline surface.

2 Select Change Normal Direction (Surface Task, S + 6).

3 Identify the orange B‐spline surface. Enter a data point to change the

normal direction.Surface Normals pointing down


Boolean tools

4 In the Solids Task, select Subtract Solid (T + 9), with Keep Originals set to None.

5 Identify the green slab.

6 Identify the orange B‐spline surface.

7 Accept to complete the operation.

The part of the solid that is retained is below the surface, in the direction that the surface normals were pointing.

Using the 3D primitive solids, extrusions and the three boolean tools, you can create the basics for quite complex models. Other tools in the 3D Modify task let you add cuts, fillets and chamfers.

Cut Solids by Curves tool

With the Cut Solid tool, you can place a cut in a solid using a template or cutting profile. Cutting profiles may be open or closed elements, but open elements must extend to the edge of the solid. When you use an open element as a cutting profile, the identification point for the solid determines the portion of the solid that is retained. If Split Solid is enabled, however, no material is removed. In these cases, the solid is merely split at the cutting profile. Tool settings are as follows.

• Cut Direction sets the direction of the cut, relative to the cutting profile’s Surface Normal.

Both: Cuts both directions from the profile’s plane


Boolean tools

Forward: Cuts forward from the profile’s plane (in the direction of the Surface Normals).

Back: Cuts back from the profile’s plane (in the reverse direction of the Surface Normals

• Cut Mode sets the limits of the cut.

Through: Cuts through all faces of the solid.

Define Depth: Cuts into the solid a defined distance.

• Cut Depth(Cut Mode set to Define Depth only) Sets the depth of the cut.

Split Solid: If on, no material is removed from the solid; it is split into 2 or more segments.

Keep Profile: If enabled, the original cutting profile remains in the model

In the following exercise, you will use a template of the earthworks cross‐section to place a cut in the existing ground section that you created previously. You will see that you can change the settings for the cut prior to accepting.

Exercise: Place a cut using a cross‐section template

1 Continuing in Advanced_Solids.dgn, open the model 13_Cut Solid 1.

2 Select Cut Solid by Curves (T + Q), with the following tool settings:

Cut Direction: Forward

Cut Mode: Through

Split Solid and Keep Profile: Disabled

3 In any view, identify the green solid.

4 Identify the red cutting profile.

The direction arrow for the cut is pointing away from the solid. This is clearly visible in the Top, Front, and Isometric views.

5 Change the following tool setting:


Boolean tools

Cut Direction: Back

Note that the direction arrow now points toward the solid.

6 Accept to make the cut.

If you had enabled Split Solid, then the cut would have split the solid, but not removed the cut section. You could use this procedure when you want to measure the volume of the material being removed, using the Measure Volume tool. The cut volumes could be stored on a separate level for future checking.

When you have multiple cuts to apply to a solid, you can perform the operation in 1 step by selecting all the cut profiles prior to selecting the tool. For example, you could create a shell of a building and then draw blocks for the windows and doorways. These could be cut in a single operation. The direction of the cut is controlled by the surface normal of the cutting profile and the Cut Direction setting of the Cut Solid tool. In the following example, the cutting profiles all have their surface normals pointing away from the center of the building.

Exercise: Place multiple cuts in a solid


2 Select Element Selection (1) and use it to select all of the red cutting profiles.

Hint: Use element attributes and Element Selection to select more quickly.


Boolean tools


Cut Direction: Forward

Cut Mode: Through

Split Solid and Keep Profile: Disabled

4 Identify the green building shell with a data point.

5 Accept with a data point to complete the cuts.

6 The openings for the doorways and windows are cut through the solid.

Before (left) and after (right) cutting the window and doorway openings.

If you want to place cuts only part way through a solid, you can set Cut Mode to Define Depth and specify the Cut Depth. In the following exercise, for example, you will cut slots into a timber stairway stringer to accommodate the steps. The profiles for the steps have been located on the face of the stringer.

Exercise: Place a partial cut in a solid


2 Select Element Selection (1) and select all the red rectangular profile elements.

All the cutting profiles are highlighted.


Cut Direction: Back

Cut Mode: Define Depth

Cut Depth: 25

Split Solid: and Keep Profile: Disabled


Boolean tools

While you only require the cut to be in 1 direction, you can use Both in this situation because the profiles are on the surface of the solid. This saves you time checking the direction of the profiles’ surface normals in order to select the correct cut direction.

4 Identify the green solid.

5 Accept to complete the construction.

Hidden line view of the completed stringer

Fillets and Chamfers

You can use the Fillet Edges and Chamfer Edges tools to apply rounding or chamfers to 1 or more edges of a solid, extruded surface, or surface of revolution. From a basic solid, you can add fillets and/or chamfers to produce the finished design.

Fillet Edges tool

Tool settings for this tool let you define the radius of the fillet and whether to select tangential edges.

• Radius defines the radius of the fillet.


Boolean tools

• Select Tangent Edges: If on, edges that are tangentially continuous are selected and filleted in 1 operation.

Chamfer Edges tool

Tool settings for this tool let you define the trim distances for the chamfer, whether to select tangential edges, and the option to reverse the trim distances for the chamfer where they differ.

• Distance 1 and Distance 2: Sets the distances to trim back the faces.

• Lock Control: If enabled Distance 1 and Distance 2 are constrained to the same value. If disabled Distance 1 and Distance 2 may be different values

• Select Tangent Edges: If on, edges that are tangentially continuous are selected and chamfered in 1 operation.

• Flip Direction: When Distance 1 and Distance 2 are different, reverses the direction of the chamfer and the values that the faces are trimmed.

Selecting edges for filleting or chamfering

After identifying the solid, as you move the screen pointer over it, the edge nearest the pointer highlights. Entering a data point selects the highlighted edge, which then remains highlighted. To select additional edges, simply hold down the Ctrl key and move the pointer over the solid. You then can use Ctrl data points to select any additional edges for chamfering or filleting.

Deselecting edges for filleting/chamfering

Where you select an incorrect edge, a Reset deselects the edge. If you have selected a number of edges, consecutive resets will deselect the edges in the reverse order. The last edge selected is the first edge deselected.

How to fillet/chamfer 1 or more edges of a solid, extruded surface, or surface of revolution:

Select the Fillet Edges or Chamfer Edges tool.

Identify an edge to fillet/chamfer with a data point. The solid highlights with the selected edge highlighted in a heavier weight line.

Enter a data point away from any of the edges to accept the construction.

— or —

Using Ctrl data points, identify additional edges to be filleted/chamfered.


Boolean tools

Enter a data point away from any of the edges to accept the construction of fillets/chamfers at all the selected edges.

Correcting an incorrectly constructed chamfer

When you construct a chamfer with different values for Distance 1 and Distance 2, it may be in the wrong direction. Distance 1 and Distance 2 are applied to the wrong faces.

How to correct a chamfer that is constructed in the wrong direction:

1 Undo the chamfer(s).

2 Enable Flip Direction.

3 Reconstruct the chamfer(s).

Let’s see how the fillet and chamfer tools work. In the next exercise, you will finish a glass topped table, adding rounding and chamfers to its basic form.

Exercise: Fillet an edge of a solid

1 Continuing in Advanced_Solids.dgn, open the model 16_Fillet.

2 Select Fillet Edges (T + W) with the following tool settings:

Radius: 20

Select Tangent Edges: Disabled

3 Identify the inside edge of the table’s frame at location 1 with a data point.

The solid highlights with the selected edge additionally highlighted.

4 Move the pointer away from any edges and accept with a data point.

The fillet is constructed for the selected edge.

Left: the selected edge highlighted. Right: the completed fillet.

Multiple edges can be filleted (with the same radius) in the 1 operation.


Boolean tools

Exercise: Fillet the remaining edges of the frame

1 Continuing in Advanced_Solids.dgn, in the model 16_Fillet, with Fillet Edges still active, identify the inside edge of the frame at location 2.

The edge highlights.

2 While holding the Ctrl key, move the pointer over the solid and note that the edges highlight as the pointer passes over them.

3 Enter a Ctrl data point at locations 3, and 4.

These edges now highlight along with the first edge selected.

4 Releasing the Ctrl key, move the pointer away from any edges and enter a data point to complete the construction.

All 3 edges are filleted.


Radius: 45

6 Use Ctrl data points to select the outer edges of the frame near locations 1 through 4.

7 Move the pointer away from any edges and enter a data point to complete the construction.

When applying fillets to a solid, you should consider the order in which the fillets are applied. Because you filleted the corners of the table frame first, you will now be able to fillet the edges of the frame in 1 step, using the Select Tangent Edges setting.

Exercise: Fillet the vertical edges of the table frame


Boolean tools

1 Continuing in Advanced_Solids.dgn, in the model 16_Fillet, select Fillet Edges (T + W) with the following tool settings:

Radius: 7.5

Select Tangent Edges: Disabled

2 Identify the vertical edge of the table frame at location 5.

Note that only the straight section of the edge highlights.

3 Reset.


Select Tangent Edges: Enabled

5 Identify the edge at location 5.

Note that the entire edge highlights this time.

6 Accept, away from the solid, to complete the construction.


Boolean tools

7 Complete the table frame by filleting the remaining 7 vertical edges, along with their tangent edges.

When you select an edge for a fillet or chamfer and the wrong edge highlights, you can reset until the correct edge highlights. If you are selecting multiple edges using Ctrl data points, you can still reset, without the Ctrl key, to highlight the correct edge before proceeding. You may need to make use of this method during rounding of the corners of the table top.

Exercise: Round the corners of the table top

1 Continuing in Advanced_Solids.dgn, in the model 16_Fillet, select Fillet Edges (T + W) with the following tool setting:

Radius: 40

2 Enter a data point on the lower left vertical edge of the blue table top. If the incorrect edge highlights, enter resets until the short vertical edge is highlighted.

3 Use a Ctrl data point to select another of the vertical edges of the table top.

If the incorrect edge highlights, release the Ctrl key and reset until the correct edge highlights.


Boolean tools

4 Repeat the previous step to select the remaining corners of the table.

5 When all 4 corners are selected, accept with a data point entered away from the solid.

Chamfers are applied the same way as fillets. In this exercise, you will add chamfers to the upper and lower edges of the glass table top.

Exercise: Chamfer the upper and lower edges of the table top

1 Continuing in Advanced_Solids.dgn, in the model 16_Fillet, select Chamfer Edges (T + E) with the following tool settings:

Distance 1 and Distance 2: locked and set to 5

Select Tangent Edges: Enabled

2 Identify the top edge of the blue table top.

The entire edge highlights.

3 Use a Ctrl data point to identify the lower edge of the blue table top.

Both edges now are highlighted.


Boolean tools

4 Move the pointer away from the highlighted edges and accept with a data point.

Detail showing corner of table top before (left) and after (right) chamfering the edges.

Taper Solid tool

The Taper Solid tool is used to narrow or widen one or more faces on a solid. The amount of taper applied is controlled by the Draft Angle setting.

• Draft Angle: Sets the angle to be applied to the taper. The draft plane is parallel to the face that is to be tapered.

• Add Smooth Faces: If on, any tangentially continuous faces are included with the selected face. If off, only the selected portion of the tangentially continuous face is tapered.

Selecting the face(s) to taper

After identifying the solid, as you move the screen pointer over it, the face nearest the pointer highlights. Entering a data point selects the highlighted face, which then remains highlighted. To select additional faces, simply hold down the Ctrl key and move the pointer over the solid. You then can use Ctrl data points to select any additional faces for removal.

To select a face that is behind another face in the view, enter a data point, or Ctrl data point, on the face, which will highlight the nearest face. Then reset until the required face highlights.


Boolean tools

Deselecting faces to taper

If you select an incorrect face, a reset deselects the face. If you have selected a number of faces, consecutive resets will deselect the faces in the reverse order. The last face selected is the first face deselected.

Defining the taper origin

After selecting the face(s) to be tapered, the next data point defines the start point for the taper. This can be a point above or below the selected face.

Exercise: Taper a single face

1 Continuing in Advanced_Solids.dgn, open the model 17_Taper 1.

2 Select Taper Solid (T + 4), with the following tool settings:

Draft Angle: 5

Add Smooth Faces: Disabled

3 Identify the solid so that it highlights.

4 Move the pointer to location 1 and enter a data point to highlight the face.

Only the selected face highlights in a different color.

5 Snap to the vertex at location 2, and enter a data point to set the starting point of the taper. Choose Front, <F> or Side, <S> rotation.


Boolean tools

6 Snap to the vertex at location 3 to define the draft plane normal vector for the taper.

7 Accept to taper the selected face.

After tapering the face.

In the previous exercise, you tapered just the selected section of a face that is tangentially continuous around 3 sides of the solid. If required, you can taper all sections of such a face in 1 step.

Exercise: Taper multiple (tangentially continuous) faces

1 Continuing in Advanced_Solids.dgn, open the model 18_Taper 2.

2 Select Taper Solid (T + 4), with the following tool settings:

Draft Angle: 5


Boolean tools

Add Smooth Faces: Enabled

3 Identify the solid so that it is highlighted.

4 Move the pointer to location 1 and enter a data point to further highlight the face.

5 The selected face highlights, along with all tangentially continuous faces.

6 Snap to the vertex at location 2, and enter a data point to set the starting point of the taper.

7 Snap to the vertex at location 3, to define the draft plane normal vector for the taper.


Boolean tools

8 Accept to taper the selected faces.


Edit 3D Primitive tool

At times, you may place a number of 3D primitives, extrusions or revolutions as a starting point in creating a more complex solid. After you have placed any of these elements in a model, you can use the Edit 3D Primitive tool to modify them by editing their parameters. Dimensions available for editing depend on the 3D primitive element selected.

Note: If you require greater flexibility with parametric editing of solids, you should work with feature solids.

3D Primitive Editable parameters

Slab Length, Width, and Height

Sphere Radius

Cylinder/Cone Top Radius, Base Radius, and Height

Torus Primary Radius, Secondary Radius, and Angle

Wedge Radius, Angle, and Height

Extrusion Distance

Revolution Angle of revolution


Module Review

How to edit a 3D primitive:

1 Select the Edit 3D Primitive tool (T + R).

2 Identify the primitive.

3 Accept to open the Edit dialog.

4 Make changes to the parameters in the dialog as required.

5 Click OK to make changes.

You can see how this tool works for yourself. A number of example solids are present in model EXTRA_Edit Primitives, in Advanced_Solids.dgn.

Module Review


Questions

1 What does the Solids setting in the Working Areas section of the DGN File Settings dialog’s Advanced Unit Settings dialog do?

2 What happens if you increase the size of the solids modeling area?

3 When using Extrude Along Path, how can you specify that the extrusion is attached to the path element?

4 What do the Boolean tools do?


Module Review

Challenge Exercise: Draw a solid

1 Draw the following solid (all dimensions are shown in mm).

Start with a 40 x 40 x 10 slab.

Draw a block and create the 12 x 6 (through) cutout at the rear of the object.

Draw 2 19 x 18 blocks and create the 6 deep cutouts in the top face.

Add the 6 x 6 chamfer and the 6 radius fillet.


Module Review

Challenge Exercise: Draw an Impeller

1 Draw the following solid (all dimensions are shown in mm).

There are many approaches to creating a 3D solid model. The following are suggested techniques for creating the impeller:

• Solid by Extrusion or cylinder solid

• Solid by Extrusion Along

• Copy by Polar Array

• Modify Solid Entity


Module Review

Answers

1 It lets you set a working area that determines the degree of accuracy for solids calculations.

2 It will reduce the available precision.

3 By snapping to the profile, at the point on it that you want attached to the path element.

4 The let you unite, intersect, or subtract solids. They let you create a complex solid from 2 or more existing solids.


Solid Utilities

Module Overview

The Solids Utility toolbox contains tools that help with extracting parts of a solid and changing the properties of a solid among other useful tools.



• Knowledge of Basic and Advanced Solids Modeling

Module Objectives


• Relocate elements so that their faces are aligned

• Change the display of SmartSolids

• Extract a face, edge or untrimmed surface from a solid

• Intersect a solid or surface with a linear element

• Convert to SmartSolid/Surface

Feb-09 193 Solid Utilities





Questions


2 If you select an incorrect element, how do you deselect it?

Answers


2 A reset deselects. If you have selected a number of faces, consecutive resets will deselect the faces in the reverse order.

Solid Utilities 194 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Utility Tools

Utility Tools

These tools are used with existing solids in the model.

Solid Utilities opened as a toolbox

• Align Faces: Move an element and align a selected face of it to the selected face of a second element.

• Change SmartSolid Display: Change the display of SmartSolids/SmartSurfaces.

• Extract Face or Edges: Extract a face, or edge, from a solid or surface.

• Intersect Solid/Surface with Curve: Find the intersection point between a solid/surface and a linear element.

Align 3D tool

If a 3D model consists of several individual components, it is often convenient to create each component separately and then assemble them later. If the assembly requires manipulating elements so that various faces align with each other, use the Align 3D tool.

This tool is used to align the selected face of the first element to the selected face of a second element. It is very useful for aligning various parts of a model, where

Feb-09 195 Solid UtilitiesCopyright © 2009 Bentley Systems, Incorporated

Utility Tools

1 or more of the faces do not coincide with the model coordinate system. In aligning the faces, various tool settings let you choose how the alignment is performed. Tool settings are as follows.

• Method: Sets the way that the planes of the faces are selected.

• Face to Face — Aligns the face of one solid or surface with the face of a second solid or surface with two arrows. The blue arrow is used for position and the red arrow is used for rotation. The ball portion of both arrows can be moved to a new location by dragging with the Data button pressed.

• Plane to Plane — Aligns one element to a second element by describing a plane with an origin and x, y‐axis on each element. The direction of the Z axis is controlled by an arrow.

• Plane to Curve — Aligns a planar element or an element that contains a plane normal to a linear element or curve element. The location and rotation of the planar element can be adjusted along the linear or curve element by dragging or changing the direction of the arrows.

• Keep Original: If on, a copy of the first element is used and the original element is not manipulated.

Selecting faces

After you have identified the solid, moving the pointer over it highlights the face nearest the pointer. When the required face highlights, enter a data point to select it. To select a face that is behind another, simply enter a data point on it, which will highlight the nearest face, and then reset until the required face is highlighted.

The ball and arrows

The arrows on the element that is being moved can be adjusted by using the following:

Blue Arrow ‐ Click and drag on blue arrow to change direction.

Black Ball ‐ Click and drag to move the black ball portion of the arrow to a new location.

Red Arrow ‐ The rotation can be changed by selecting the edit handle at the end of the red arrow. When this is selected, an edit circle along the axis of the blue arrow will allow rotation.


Utility Tools

The arrows on both elements can be changed to the desired rotation of the element during the preview state.

The blue arrow at the new location by default will line up with the blue arrow of the element to be moved.

Changing the direction of this arrow does not change the location of anything. It should not be changed from the default direction.

General procedures to align in 3D

How to align in 3D using Face to Face:

1. Select the Align 3D tool with Method set to Face to Face.

2. Identify the element to align.

3. Move the pointer over the element to highlight (with yellow dashed lines) the required face and enter a data point to accept.

4. Identify the second element or Ctrl+Data to select more elements to align.

5. Move the pointer over the element to highlight the required face and enter a data point to accept.

6. Use Black ball on source face to align by snapping to edges or vertices. Adjust under desired result is achieved.

How to align in 3D by Plane to Plane:

1. Select the Align 3D tool with Method set to Plane to Plane.

2. Identify the element to align.

3. Snap to the desired origin point and enter a data point to accept the element. This will define the ‘from’ coordinate origin.

5. Define the ‘from’ coordinate first axis point. A red arrow displays, showing the direction of the first (x) axis.


Utility Tools

6. Define the ‘from’ coordinate second axis point. Green and blue arrows display, showing the direction of the second (y) and the third (z) axis’ directions, respectively.

7. Define the ‘to’ coordinate origin. This defines the origin point for the relocation. The first element’s origin point will be located at this point.

8. Define the ‘to’ coordinate first axis point. A red arrow displays, showing the direction of the first (x) axis.

9. Define the ‘to’ coordinate second axis point. Green and blue arrows appear, showing the direction of the second (y) and the third (z) axis’ directions, respectively. At the same time, the first element is relocated with its defined axes aligning with the defined axes of the second element.

10. Accept the relocation with a data point. Alternatively, click the and drag the blue arrow on source to reverse the direction of the re‐located element. This action completes the command.

How to align in 3D by Plane to Curve:

1. Select the Align 3D tool with Method set to Plane to Curve.

2. Select the element to be moved.

This can be any element that will describe a plane. The simplest is a line string with two segments. A curve is also valid as long as a plane can be derived.

3. Select the element to move to.

This can be any element that contains a line or a curve. It can be a B‐spline curve, the edge of a surface or solid that can be used for a sweep curve, and so on. In the preview there will be a direction arrow and a rotation ball on both elements. The direction of the arrow can be changed as needed. The location of the arrow can be changed by dragging with the Data button pressed. The rotation arrow can be used to change the rotation of the profile.


Utility Tools

4. Press the Data button to accept or Reset to reject.

In the next exercise, you will align a face of the red slab (marker 1) with the sloping face of the green solid (marker 2), using the Face to Face method to orientate the slab.

Exercise: Align 3D with two 2 solids using Face to Face


User: untitled


2 Open Solids_Utilities.dgn.

3 Open the model 01_Align 1.


Utility Tools

4 With the Solids Modeling task active in the Task Navigation dialog, click Align 3D and select Open as ToolBox.

5 Select Align 3D (A+2), with the following tool settings:

Method: Face to Face

Keep Original: Disabled

6 Identify the red slab with a data point.

The slab highlights.

7 Move the pointer over the solid to highlight the left face, identified by location marker 1.

8 When the face highlights, accept with a data point.

The face remains highlighted and has the ball and arrow on it.

9 Move the ball and red arrow, then click n the blue arrow to reverse direction as shown below.


Utility Tools


The solid highlights.

11 Move the pointer over the solid to highlight the sloping face, identified by location marker 2.

12 When the face highlights, accept with a data point.

The dynamic copy of the red slab re‐locates with its identified face abutting that of the green solid.

13 Select the red arrow handle and snap to the mid‐point of the lower edge of the sloping face.


Utility Tools

14 Select the black ball and snap to the mid‐point of the upper edge of the sloping face.

15 On the source solid (location 1) move the black ball to the mid‐point of the lower edge and watch the result on the re‐located solid.


Utility Tools

16 Returning to the re‐located solid, you can now move the lack ball down to the mid‐point of the face using AccuDraw.


The slab is located on the sloping face of the green solid.

18 Check the other views, particularly the right view, to verify that the red slab is correctly aligned with the face of the green solid.

After aligning the red slab

The previous exercise can be shortened with better use of AccuDraw and snapping.

Try the Plane to Curve option with the line behind the green solid.


Utility Tools

Next, you will align the barrel tile to the roof, by placing 1 on each roof. As an extra exercise, you can also place the skylight on the roof.

The following method is Plane to Plane. Here you will define the origin and two points to create a source plane, and then another origin and two point to define the destination plane.

Exercise: Align skylights to roof with Plane to Plane

1 Continuing in Solids_Utilities.dgn open the model 02_Align 2.

2 Select Align 3D (A+2), with the following tool settings:

Method: Plane to Plane

Keep Original: Enabled

3 In View 3, following the status bar prompt, snap to the base of the barrel tile (the lowest point of the rectangle) and accept with a data point.

4 Snap to the right end point of the base to set the x‐axis direction of the plane.


Utility Tools

5 Snap to the left end of the base and accept with a data point.

6 In View 2, snap to the lower left point on the top face of the roof solid and accept the origin of the destination plane.

7 Snap to the right of top edge as shown and accept for x‐axis direction and accept.

8 Snap to the left of top edge as shown and accept for y‐axis direction and accept.


Utility Tools

9 Press the data button to accept the alignment.

Optional Exercise: Using ACS

1 Repeat the previous exercise, using ACS planes for the roof planes.

Change SmartSolid Display tool

By default, when you place SmartSolids in a model, they display in Wireframe display mode. Their display is controlled by the Display Mode setting in the B‐spline and 3D dialog.

When you need to change the value for an existing element, however, you can use the Change SmartSolid Display tool.

Surface/Solid Iso Lines are used to represent curved surfaces and curved faces on solids. The Surface/Solid Iso Lines setting applies to curved surfaces and lets you define the number of rule lines for curvature.

Another option is to set the Display mode for SmartSolids to be either Wireframe (the default) or Surfaces. Surfaces mode should be used only when the design is to be rendered in previous versions of MicroStation. Finally, you can choose to suppress the display of B‐spline Faces and/or Complex Blending Faces.

Tool settings are as follows.

• Surface/Solid Iso Lines: Sets the number of iso lines that represent a full 360° of curvature of curved surfaces for SmartSolids and SmartSurfaces.

U Rules — Sets the number of lines in the U direction (Rows).

V Rules — Sets the number of lines in the V direction (Columns).

• SmartSurface/Solid: Lets you set the display mode for SmartSolids and SmartSurfaces:


Utility Tools

• Surfaces — required only if the design is to be rendered with a previous version of MicroStation.

• Wireframe — the default display mode, which should be used unless the design is to be rendered with a previous version of MicroStation.

• Suppress Rule Lines: Lets you suppress, or turn off, the display of rule lines for particular faces on SmartSolids and SmartSurfaces.

• B‐spline Faces — If on, display of rule lines on B‐spline faces can be suppressed.

• Complex Blending Faces — If on, display of complex blending faces can be suppressed.

When working in wireframe screen display mode, curved surfaces sometimes are not clearly displayed in 1 or more views. You can remedy this by changing the number of surface rule lines that define these curved surfaces.

Exercise: Change the number of surface rule lines used to display a curved solid

1 Continuing in Solids_Utilities.dgn, open the model 03_Display.

This model contains a solid that was created by adding thickening to a B‐spline surface. While each view displays the solid, it is not clear just where the surfaces are located. Currently, the number of U and V Rules are set to 2. Increasing this number will help you visualize the surface.

2 From the Solids Modeling task, select Change SmartSolid Display (A+3) with the following tool settings:

U Rules: 4

V Rules: 4

Display Mode: Wireframe

3 Identify the green solid in any view.

The solid highlights.



Utility Tools

The display of the green solid updates with extra rule lines displaying the shape of the solid’s surfaces.

Solid with U and V Rules set to 2 (left) and to 4 (right)

Extract Face or Edge Geometry tool

You can use this tool to extract a face or an edge from a solid. Many solids are created by adding cuts, fillets and chamfers to an underlying primitive solid, such as a slab. Using the Extract Face or Edge Geometry tool, you can create a separate element that matches a face or an edge of the solid. This may be used to create a template or profile, which you can use to create a further solid.

Selecting faces/edges for extraction

After identifying the solid, as you move the screen pointer over the solid, the face or edge nearest the pointer highlights. Entering a data point selects the highlighted face or edge, which then remains highlighted.

You can use data points to select multiple edges. To do this, after selecting the first edge, you move the pointer to highlight the next edge and then enter a data point to select it.

For faces, you can use Ctrl data points to select multiple faces. To do this, after selecting the first face, you hold down the Ctrl key and move the pointer to highlight the next face and then enter a data point to select it.

Where you want to select a face that is located behind another face in the view, select the face that is in front and then press Resets until the required face highlights.

Deselecting faces/edges for extraction

If you select an incorrect face or edge, reset to deselect it. Where you have selected a number of faces or edges, consecutive Resets deselect them in the reverse order. That is, the last face or edge selected is the first deselected


Utility Tools

Tool settings for this tool let you define the symbology (level, color, weight and style) of the extracted face or edge.

• Extract: Sets the type of element to be extracted

Faces — extracts selected faces from solid.

Edges — extracts selected edges from solid.

Untrimmed Surfaces — extracts an untrimmed surface from solid. That is, a simple surface, less any cuts, chamfers, fillets.

• Level, Color, Weight and Style: Define these attributes for the extracted element.

Exercise: Create a spacer by extracting a face of a flange

1 Continuing in Solids_Utilities.dgn, open the model 04_Extract.

This is a model of a short length of pipe with a flange. You will create a spacer for the pipe flange. You will use the extracted face from the flange as the template to extrude the spacer.

2 Select Extract Face or Edges (A+4) with the following tool settings:

Extract: Faces

Level: Enabled and set to Default

Color: Enabled and set to red (color 3)

Weight and Style: Disabled

3 Identify the pipe and flange.

The solid highlights. As you move the pointer over it, the face nearest the pointer highlights.

4 In View 3, move the pointer to highlight the bottom face of the flange and enter a data point.


Utility Tools

5 Move the pointer away from any faces and enter a data point to complete the extraction of the face.

6 Make Default the active level.

7 In the Isometric view, turn off the level Geometry.

To complete the spacer, you can extrude this extracted element.

8 Select Solid by Extrusion (R + 1) with the following tool settings:

Orthogonal: Enabled

Distance: Enabled and set it to 15

9 In the Isometric view, identify the red spacer element you just extracted.

10 Move the pointer downward to define the direction of the extrusion and enter a data point to complete.

Pipe, flange and extruded spacer in Smooth display style


Utility Tools

Compute Intersections tool

With this tool, you can find the intersection point between a solid or a surface and a linear element (curve). Optionally, you can have points, normals, or both points and normals placed at the intersection points.

Exercise: Intersect a solid with a linear element

1 Continuing in Solids_Utilities.dgn, open the model 05_Intersect.

2 Select Compute Intersections (S+5) with the following tool settings:

Normals at Intersections: Enabled

3 Identify the green surface with a data point.

The surface highlights.

4 Identify the white dashed line.

The line highlights.


6 Points and normals appear at each intersection point of the line with the solid.

View showing the points and surface normals at the intersection points


Convert To Solid

This tool can be handy when you have created a slab or extruded a complex shape as a surface, and you want them to be solids. Use the tool to convert the surface elements to solids. If the surface model is a primitive shape such as a slab,


Utility Tools

cylinder, torus, etc., use the Primitive Solid option and for all other surface models use the SmartSolids option.

Exercise: Converting a surface to a solid

1 Continuing in Solids_Utilities.dgn, open the model 06_Convert.

2 Click the View Display Mode tool and change the display mode to Smooth.

As you can see, the geometry has no front or back surface.

3 Select Convert To Solid (A + 1) with the following tool setting:

Convert To: Solid

4 Identify the extruded surface.

The surface highlights.


Looking at the rendered view, you can see that it now has at least a front face. If you check the element with the Element Information tool, you will find that it is a solid.


Note that the front and back faces have added to create a Smart Solid

6 Check with Element Information.

Module Review


Questions

1 True or False: The Solids Utility tools are used to place solids in a model.

2 When using the Align Faces tool, which method lets you control the location and orientation of the relocated element?

3 By default, when you place SmartSolids in a model, they display in what display mode?

4 Where can you change the SmartSolid display mode?

5 What does the U direction represent?

6 What does the V direction represent?

Answers

1 These tools are used to work with existing solids in the model.

2 The By 3 Points method.

3 By default, when you place SmartSolids in a model, they display in Wireframe display mode.

4 The Display Mode setting in the B‐spline and 3D dialog.

5 Rows.

6 Columns.


Module Review


Conceptual Modeling

Module Overview

Push‐Pull Modeling or Conceptual Modeling technology lets you quickly create and modify solids interactively, by adding or removing faces and vertices and pushing and pulling faces and vertices.



• Knowledge of Basic Solid Modeling

Module Objectives


• Use the Draw on Solid tool

• Use the Modify Solid Entity tool

• Use the Delete Solid Entity tool

Feb-09 215 Conceptual Modeling





Questions

1 How can you to move focus to the AccuDraw window?


Answers



Conceptual Modeling 216 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Conceptual Modeling Tools


Draw on Solid

The Draw on Solid tool is in the 3D Modify toolbox. It lets you draw lines, shapes, and circles, directly onto the face of an existing solid, or you can imprint a curve onto the face. These additions become faces that can be modified with the Modify Solid Entity tool, which lets you push and pull on faces and vertices.

The tool recognizes the nearest face under the pointer and matches the AccuDraw drawing plane to the selected face.

Note: If a drawn line does not intersect with an existing edge, it is extended or trimmed back to the edge.

Draw on Solid is used to create an edge on a solid by drawing the following onto the face of a solid:

• Line

• Line string

• Block

• Circle

• Shape

Feb-09 217 Conceptual ModelingCopyright © 2009 Bentley Systems, Incorporated


• or imprinting a Curve

Using Draw on Solid on a face of a slab

The solid, including the newly created edges, vertices and faces can be modified with the Modify Solid Entity tool, or deleted with the Delete Entity tool.

Modifying the newly created edge

For the Imprint Curves option, you can select a face located behind another by entering 1 or more resets, or using a different view.

Imprinting a curve onto a face of a solid.

The Offset option lets you draw lines offset from edges of the face of a solid. These edges can include edges previously drawn on the face of the solid.

• Loop — Selects all edges surrounding the identification point on the face of the solid.

• Edges — Lets you select one or more edges on a face of a solid. Use <Ctrl> + Data points to select additional edges.

Exercise: Quick Test of Draw On and Modify Solid



1 In a new file, try re‐creating the above solids.

2 Use Place Slab, then Draw On Solid.

3 Then use Modify Solid to adjust the solid.

Modify Solid Entity

The Modify Solid Entity tool is in the Solids Modeling task. It is used to manipulate a face, edge, or a vertex, of a solid by pushing or pulling it interactively.

Icons in the tool settings let you select All, a Face, an Edge, or a Vertex when you are selecting the item to modify. These options determine what you modify, and how the entity is selected.

Tool Settings are as follows.

• All: Lets you select a visible face, or any edge or vertex on a solid in the view.

• Face: Lets you select a face on any identified solid in the view. By default the nearest face is selected, with resets letting you select hidden faces on the same solid.

• Edge: Lets you select any edge on any solid in the view.

• Vertex: Lets you select any vertex on any solid in the view.

• Distance: If on, sets the distance that the face, edge, or vertex, is to be modified.

• Extrude Faces: If on, the selected face is extruded. If off, the selected face is moved and adjusted along with the adjacent sides.


Conceptual Modeling Basics

• Full Dynamics: If on, dynamic display shows the modified element as you move the pointer. If off, an arrow graphic indicates the direction and extent of the modification.

Delete Solid Entity

This tool is in the 3D Modify toolbox. It is used to delete a solid entity from a solid other than a feature solid.

When selecting faces, the nearest face always is selected. You can rotate the view, or use another one, to select a hidden face. If need to delete multiple faces, you can select the additional faces with a Ctrl data point.


Conceptual modeling tools let you interactively push‐pull solids to modify their faces, edges, or vertices. This lets you quickly create and modify solids interactively.

Drawing lines on a Solid face

Figure 1. line drawn on face

In Figure 1, a line was drawn from the midpoint of the left edge of the Solid, to the midpoint of the right edge, using the Draw on Solid tool with the Draw Line option enabled.



In Figure 2. the line, which is now an edge, has been pulled in the Z axis using the Modify Solid Entity tool.

Figure 2. Edge pulled in Z axis.

The following images show the process of creating the final design concept using the previous tools.

Figure 3. Draw on Solid Figure 4. Modify Entity Extrude Face

Figure 5. Draw on Solid Figure 6. Modify Entity other side



Projecting lines on a Solid face

Basic MicroStation elements such as lines, shapes and B‐spline curves can be projected on to Solid faces. These elements become edges after projection. These edges can be modified by extruding a face and moving an edge or vertex.

Figures 7‐9. Curves projected onto Sold face then modified into conceptual design


Create a Conceptual Design


Exercise: Create the design shown in the image

1 Open the model Design Concept in Conceptual Modeling.dgn.

2 Turn on the Level designconcept_steps.

3 Select the Solids Modeling task.

4 Select Draw on Solid (T+1), read the prompt, and in the tool settings select:

Imprint Curves: Enabled

5 Imprint both the Octagonal shapes onto the base solid.

Remember to select the Solid face onto which the curves are to be imprinted.

6 Using Modify Solid Entity (T+2), read the prompt and select the face of outer imprinted shape and extrude that face 0.25 meters.

This will create the second step in the design.



7 Using Modify Solid Entity (T+2), read the prompt and select the inner shape and extrude up by 0.5 meters.

This will create the third step of the base.

Front view of base

8 Turn on the Level designconcept_columns.

Column curves display.

9 Select Draw on Solid (T+1) and the the Imprint Curves tool setting and imprint each of the columns onto the face of the base solid model.



10 Select Modify Solid Entity (T+2), enable the Select Face option, and extrude face of each imprinted column a distance of 10 meters.

Hint: To save time, turn on the Level designconcept_roof to display the a second completed model of the roof for this design.



This model used Draw Line on Solid and the Modify Solid Entity Vertex option to create the roof shape.

11 Use the Construct Union Tool to unite both models into one Solid model.

Optional Exercise: Create the roof model

1 Create the octagonal shape.

2 Extrude the shape .5 meter.

3 Draw lines on the solid.

4 Use Move Vertex.


Module Review


Questions

1 What is Push‐pull modeling technology?

2 What do you use the Draw on Solid tool for?

3 What do you use the Modify Solid Entity tool for?

4 What methods can you use to select faces that are hidden?

Answers

1 Push‐pull modeling technology lets you quickly create and modify solids interactively, by adding or removing faces and vertices and pushing and pulling faces and vertices.

2 To draw lines, shapes, and circles, directly onto the face of an existing solid, or to imprint a curve onto the face.

3 To manipulate a face, edge, or a vertex, of a solid by pushing or pulling it interactively.

4 Highlight the nearest face and the reset until you select hidden face. Rotate the view or use another view.


Module Review


Solid Modeling Challenge Exercises

The following is a challenging exercise series, using a variety of tools and heavy emphasis on using AccuDraw in 3D.

When selecting faces, the nearest face always is selected. You can rotate or use another view to select a hidden face, or right click to get the back face. Where you require multiple faces to be deleted, you can select the additional faces by pressing the Ctrl key and then entering a data point.

You will draw a bridge pylon. The completed pylon is on the level Completed for reference.

Exercise: Getting started

1 Create a new 3D file using the seed file 3dmetricgeneral.dgn in …\Projects\Examples\General\Seed\.

2 Choose the Solids Modeling task.

3 Arrange the views as desired.

4 From the Solids Modeling task, select Place Slab (E+1).

5 With focus on AccuDraw (Esc + space bar) use the shortcut <P> to open the absolute point placement window.

6 Enter 0,0,0 and press Enter.

7 Pan so that this first point in the lower center of your view.

8 Use the shortcut <T> to rotate to the Top plane.

Feb-09 229 Solid Modeling Challenge Exercises


9 Following the status bar prompt, enter a length of 3000, width of 3000, and a height of 10000 to place the Slab.

Using AccuDraw, you could place the block in the right place the first time, but you will use a slightly longer method to hone 3D AccuDraw skills.

Exercise: Using Draw on Solid

1 Select the Draw on Solid tool (T+1), and in the tool settings select Draw Block.

2 Select the solid and draw a block on any vertical face of the solid.

Solid Modeling Challenge Exercises 230 Feb-09Copyright © 2009 Bentley Systems, Incorporated

3 Select Modify Solid Entity (T+2) with the All icon depressed in the tool settings to edit the edges just created.

4 Select the mid‐point of the edge to modify and snap to the mid‐point of the nearest vertical edge of the solid.

5 Use the AccuDraw shortcut <O> to place the origin at the snap point.

6 Index to the axis back to the center of the face and press <Enter>.

Feb-09 231 Solid Modeling Challenge ExercisesCopyright © 2009 Bentley Systems, Incorporated

7 Key‐in 300 and data to accept the new location of the edge.

Edge moved to mid‐point to mid‐point


8 Repeat for the other vertical edge.

Second edge moved mid‐point to mid‐point


9 Continue with Modify Solid Entity and snap to the mid‐point of the upper edge of the solid.

10 Press <O>, index back to the center face, and press <Enter>.


11 Key‐in 1000 and data to accept the new location of the edge.

12 Repeat this process for the other 3 faces.

Now you will modify the face by extruding it.

Exercise: Extrude a face

1 Continue with the Modify Solid Entity (T+2)., and with Face depressed in the tool settings.

2 Select the solid and then select the newly created face, by selecting the middle of the face.

3 Data once more inside the face to accept it for modification.


4 Using AccuDraw Top or Side rotation move the face out 1000.

One face extruded

5 Now repeat on the opposite face, using the same dimensions.


6 Repeat for the other two faces except make the distance from the top 1500 and the extrusion distance to 500.

Now you will cut holes into two of the newly extruded faces.

Exercise: Draw on circle on solid and modify

1 Select the Draw on Solid tool (T+1).

2 In the tool settings, select Draw Block.

3 Draw a Block on one of the extruded faces.


4 Read the prompt and start to draw from the upper left corner of the extruded face, by using <O> for Set Origin. Index down 500 units (y) and and to the right by 700 units (x).

5 Make the block 1000 units wide by 2000 units tall.

6 Select the Modify Solid Entity tool (R+2), set your tool setting to Face.


7 Read the prompt, and select the newly created block, data to accept the face.

8 Index toward the center of the solid, key‐in 500 and accept with a data point.

9 Repeat for the opposite extruded face.

Now you will taper all the faces from the bottom.


Exercise: Use Modify Solid to Taper a Face

1 Select the Modify Solid Entity tool (T+2). with the following tool settings:

All

Full Dynamics: Enabled

2 Select the extruded face at the bottom center edge.


3 Snap to the lower left corner and accept with a data point.

4 Taper the other three faces in the same way.


Exercise: Adding a Slab, modifying it and Union to previous solid

1 Select Place Slab (E+1), and snap to the base of the extruded face with the cut‐out. Accept the origin with a data point.

2 Snap to the other end of the extruded face to define the length.

3 Index away from the solid to define the width of 250.

4 Define a height of 2500. Enter a data point to complete the solid.

5 Set the snap divisor to 3 (AccuDraw shortcut <K>).

6 Select Draw on Solid tool and choose the Draw Line method.

7 Snap to the upper one‐third of the new slab and draw a horizontal line.


Hint: You do not need to draw the entire line. The tool will draw the line to edge of the face for you.

8 Draw another line snapping to the bottom one‐third of the new slab face.

Note: You snapped to the lower 1/3 of the remaining 2/3 of the front face of the new slab.

9 Select the Modify Solid Entity (T+2) tool and select the lower face and extrude it by 500 units.

10 Continuing with the Modify Solid Entity, select the middle face and extrude it out by 250 units.


11 Select the Unite Solids tool (T+7) and select the newly modified solid and the original solid.


Introduction to Feature Modeling

Module Overview

Solids created with the Feature Modeling tools are fully editable, either using the parameters used to create them, or graphically using handles after selecting with Element Selection. If you add a feature to a SmartSolid, it is converted to a feature solid, but only those features that were placed with the Feature Modeling tools contain the intelligence of feature solids and can be edited.

When you work with the Feature Modeling tools, each item that you create is known as a feature. Each feature is stored in a feature tree, along with the parameters used to create it.

MicroStation's Feature Modeling tools let you create parametric feature‐based solids. That is, a parametric solid that is created from one or more features. Parameters used to create the features are stored in the design and can be edited with the Modify Parametric Solid or Feature tool. Alternatively, you can edit a feature interactively by selecting it with the Element Selection tool and then dragging its handles.


• Knowledge of basic MicroStation 3D tools

Module Objectives


• Set seed files for Feature Modeling

• Create Feature Solids

• Modify Feature Solids

Feb-09 245 Introduction to Feature Modeling





Questions

1 How do you limit the display depth of a view?


3 What can the Place Slab tool can be used to draw?

Answers

1 You can limit the display depth of a view by turning on the front and back clipping planes, which restrict the view to a specific slice of the design cube.


3 The Place Slab tool can be used to draw any cubic object. Using this tool, you can draw cubic solids and surfaces.

Introduction to Feature Modeling 246 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Feature Modeling Task

Feature Modeling Task

Tools for creating and manipulating feature‐based solids are located in the Feature Modeling task.

Sub‐tasks, in order, are:

• Drawing

• Primitive Feature Solids

• Boolean Feature Solids

• Profile Feature Solids

• Modify Face Features

• Manipulate Feature

• Features

• Delete Feature

• Modify Feature

• 3D Utility

• Dimension Driven Design

• Surface Modeling

Feb-09 247 Introduction to Feature ModelingCopyright © 2009 Bentley Systems, Incorporated

Feature Modeling versus Solid Modeling

Another way to look at Feature Modeling is to recognize what you can do with the tools.

The names of the sub‐tasks are similar to the tasks for Solid Modeling, and so are the specific tools, but Feature Modeling has many more tools and options.

Feature Modeling versus Solid Modeling

When should you use Feature Models and when should you use Solid Models? Generally, you should always use Feature Models since you can drop them to regular solids later if needed. In addition, Feature Modeling tools are more robust and let you use Dimension Driven Design. A downside is that Feature based solid models tend to produce slightly larger file size than regular solids because of their added intelligence.

Creating Feature‐Based Solids

Seed Files and Feature Modeling

Using the correct seed file is critical when using the Feature Modeling tool set.


Creating Feature-Based Solids

Working Area and Feature Modeling

When working with feature‐based solids, the Solids setting in the Working Areas section of the DGN File Settings dialog’s Advanced Unit Settings dialog (Settings > Design File, Working Units category) determines the largest single feature‐based solid that can be created in a model.

For example, if you set the Solids working area to be 1 kilometer, then no single solid in a model can be larger than 1 kilometer. This is the recommended setting, and should cover most, if not all, solids that you are likely to have to model.

This system of local solids working areas provides a flexible environment.

• With SmartSolids, the Solids Working Areas setting specifies the area in the model in which solids can be constructed (centered on 0,0,0). All SmartSolids should be constructed within this working area.

• With feature‐based solids, the solids working area is a local area for each solid. You can construct as many solids as you like, anywhere in the models, as long as each solid does not exceed the Solids Working Areas dimension.

Creating Feature‐Based Solids

Working with the Feature Modeling tools lets you create solids with various features in a very simple workflow:

1. Create the underlying feature solid(s).

2. Add features to the solid.

Typically, feature‐based solids consist of an underlying base solid to which features are added. The underlying solid may be a solid formed from a union of other solids, a Primitive Feature Solid, a solid created by adding thickness to a surface, or from extruding a profile.



For this initial exercise, you will start with a simple design of a square cover plate, which will start as a Primitive Feature Solid, a slab. To this slab, you will add features in the form of blends and holes.

Tools for these operations are contained in the Primitive Feature Solids and Features toolboxes. They are located in the Feature Modeling toolbox, at top left and third from top on the left, respectively.

Exercise: Draw the slab


User: untitled


2 Open Feature_create.dgn from the class data set.

3 Open the model 01_Basic Features.

4 Make the Feature Modeling tasks active in the Task Navigation dialog.

5 Select the Slab Feature tool (T + 1) with the following tool setting:

Axis: Design Z

Length and Width: Enabled and set to 100

Height: Enabled and set to 10

6 Enter 3 data points to create a slab in the center of the view.

7 Fit View.

Exercise: Round the corners and top edge of the slab

1 Continuing in Feature_create.dgn, in the model 01_Basic Features, select Blend Feature (S + 1), with the following tool settings:

Blend: Edge Constant

Radius: 15

2 Identify one of the vertical edges of the slab with a data point.



Note that the value of the radius appears at the highlighted edge.

3 Use Ctrl data points to identify the remaining three vertical edges.

If you inadvertently select the incorrect edge, reset until the correct edge highlights.

4 Accept with a data point to view the blends (rounding).

5 Accept again to complete the rounding.

If you had reset instead of accepting, the solid would have returned to its original state, without the rounding.


Radius: 5

Add Smooth Edges: Enabled

7 Identify the top edge of the slab with a data point.

8 Accept to view the rounding, and again to complete the construction.

You can use the Hole Feature for circular holes. It has options for creating a Simple, Counterbore, or Countersink hole.

You can set their direction normal to the face or they can align with the x, y, or z axis of the view, design, or active ACS. Additionally, you can specify whether the counterbore/countersink end is on the first face, the last face, or both.



When placing holes in a solid, dynamics display to show you how the hole will be aligned. When the Direction is set to Face Normal, you will see that, as you move the pointer over the solid, the dynamic hole will align itself with the nearest surface in the view.

In this exercise you will be placing 4 countersink holes, 1 at the center of the rounding on each corner. You will temporarily rotate the view to a Top view.

Exercise: Add hole features to the solid

1 Continuing in Feature_create.dgn, in the model Basic Features, select Hole Feature (S + 3) with the following tool settings:

Hole Type: Countersink

Drill: Through

Direction: Face Normal

Diameter: 10

Csink End: First Face

Csink Diameter: 12

Csink Angle: 82

2 Identify the solid.

Move the pointer over the solid and note that the hole aligns itself normal to the nearest face in the view.

3 Using the Center snap mode, snap to the center of the corner arcs and place holes at each corner arc of the solid.



Modifying Feature-Based Solids

5 Set the Isometric view’s View Display Mode to Smooth.

Modifying Feature‐Based Solids

Solids that you create with the Feature Modeling tools are referred to as feature‐based, or parametric, solids. You have much more flexibility with these solids, so you can incorporate design changes. You can modify them using the parameters used to create them, or you can modify them interactively, similar to 2D elements.

Modifying features parametrically

Feature‐based solids retain the parameters used to create them. This applies both to the underlying feature solid, as well as features applied to it. The Modify Parametric Solid or Feature tool in the Modify Feature toolbox let you quickly edit the solids and/or features by modifying their parameters.

Modifying one or more blends of a group

If you have created several blend features in a single operation, you can modify them in a single operation. Alternatively, you can choose to change the radius for selected blends of the group.

Exercise: Modify the corner blends

1 Continuing in Feature_create.dgn, and model 02_Modify Features 1.

This model is a completed version of the one you worked on in the previous exercise.

2 Select Modify Parametric Solid or Feature (Z + 1).



3 Identify any corner blend and accept with a data point (2 data points).

The tool settings show the setting used in the construction of the blend, with its current value.

4 Change the Start Radius to 25 and click OK.

5 Identify the blend along the top edge of the solid at location 2.


It is easy to add blends to several edges in a single step and you can easily modify the radius of these blends later. There will be occasions, however, where you are required to change the radius of only selected blends that were grouped together during construction. To do this, you need to enable Show all edges after you have selected 1 of the blends. The blends are numbered, letting you choose the correct blend(s) to edit.



Exercise: Modify selected blends of a group

1 Continuing in Feature_create.dgn, open the model 03_Modify Features 2.

2 Select Modify Solid Or Feature (Z + 1).

3 Identify a corner blend and accept with a data point.

Each of the blends that highlights has a number associated with it.

4 In the tool settings, enable Show all edges.

5 In the list box, highlight blends numbered 1 and 2, using Ctrl data points.


Only the selected blends are altered.



Modifying holes

When you create a hole, you have various options to choose from and several dimensions that you can specify. Similarly, if you want to modify an existing hole features in a solid, you can edit any of the settings.

Next, you will change 2 of the countersunk holes to be counterbore, plus you will change the diameters for all of the holes.

Exercise: Modify the holes


2 Select Modify Solid Or Feature.

3 Identify the hole and accept with a data point.


Hole Type: Counterbore

Diameter: 6

Cbore. Diameter: 10

Cbore. Depth: 2

5 Click OK.



6 Use the same technique to experiment with modifying the remaining holes to various settings.

Modifying the underlying solid

In the sample solid, the underlying slab feature has had various blends and holes added to it as features. Next, you will modify the slab itself. To correctly identify any feature graphically, you must identify an edge of the feature. In this case, the only remaining visible edges of the slab are along its lower edge, as all the top edges and corners have been rounded.

Exercise: Modify the slab


2 Select Modify Parametric Solid Or Feature, with the following tool setting:

Edit Solids About ID Point: Disabled

This causes modifications to be taken about the center of the solid, rather than about the ID point.

3 Identify the slab and accept with a data point.

4 In the tool settings, change the Length to 60 and click OK.



The holes no longer appear in the solid. You have decreased the length of the slab such that it is now inside the holes.

While the holes are no longer located on the solid, they still are remembered.

5 With the Modify Parametric Solid or Feature tool still active, change both the Length and the Width to 125.

6 Click OK.

The holes reappear, in their original positions. When you create feature solids, the parameters used to create the solid are retained in the model. While the holes were not visible when you reduced the length of the slab, the information for placing them still was present in the model.


Manipulating Features


You should be familiar with the 2D tools for deleting, moving, copying, mirroring, and creating arrays of elements. MicroStation’s feature modeling tools have equivalents to these tools for manipulating features.

As you complete these exercises, don’t forget that you can change the orientation of the views. The example model has been saved with the Isometric view open. Typically, this is an easy view to work in because you can see the design more clearly.

Exercise: Delete a feature

1 Continuing in Feature_create.dgn, open the model 02_Modify Feature 1.

2 Select Delete Feature.(V).

3 Identify 1 of the countersunk holes and accept to delete it.

Exercise: Moving and/or copying a feature

1 Continuing in Feature_create.dgn, in the model 02_Modify Feature 1, select Move Feature (G + 1), with the following tool setting:

Make Copy Disabled

2 With AccuDraw active, identify the remaining countersunk hole.

The compass correctly rotates to the Top view, in line with the surface of the feature solid.

3 Index to the x‐axis and press Enter for SmartLock.

This restricts movement to the x‐axis only.



4 Snap to the mid‐point of the bottom edge to define the position.

5 Accept to complete the move.

6 Reset to exit the tool.

To copy a feature, you can enable Make Copy and follow the same procedure.

7 Select Move Feature, with the following tool setting:

Make Copy: Enabled

8 Identify the counter‐bored hole.

9 Using the Center snap, snap to the center of 1 of the empty curved corners.

10 Accept to complete the copy.


Modifying and Manipulating Interactively

Other tools in the Manipulate Feature toolbox work like their 2D counterparts.


When you make changes to features interactively, the parameters associated with the feature update automatically. You still can use the parametric settings to modify the feature afterwards, if required.

To modify interactively, use Element Selection to select a feature with a data point when you want to modify or move features, or use Ctrl data point when you want to scale a solid and all its features.

When you select a feature, handles appear on the feature at the identification point, at the center, and at the modification points. As well as being able to modify the feature using menu options, you can modify the feature interactively by clicking on a modifying handle, moving it to a new location and accepting.

Exercise: Modify the slab interactively


2 Select Element Selection (1).

3 Identify the solid at the mid‐point of a base with a data point.



In this case, the modifying handles are the vertices of the underlying slab feature. Resetting on any of the handles opens a menu with various options, including Modify, which lets you modify the feature by its parameters, just as you can with the Modify Parametric Solid or Feature tool.

4 Press <T> to rotate the compass to a top view orientation.

This ensures that the pointer remains at the same z value and you are adjusting only the length and width of the solid.

5 Move the handle back and accept with a data point.



6 Enter a data point away from the solid to clear the selection.

Two of the holes are no longer present in the modified solid.

Hint: Using the handle at the center of a feature lets you move it with a data point or copy it with a Ctrl data point.

You can also adjust the blend radius, interactively, the solid is regenerated with the new radius applied to the blend

You can quickly adjust a feature solid, interactively using selection handles. Similarly, you can scale a feature solid interactively. When you initially select a solid with a Ctrl data point, handles appear at the scaling points. You then can scale the solid, and all its features, by clicking on the handle, moving it to a new location and accepting or, use click and drag. Whether you selected a solid with a regular data point or a Ctrl data point, you can alternate between the Modify handles and the Scale handles by clicking on any part of the highlighted solid, not its features, away from any handles.

You can determine what each handle does by hovering the pointer over it to display a tool tip. When the modifying handles are active, those that will modify the solid/feature display the name of the feature plus its parametric values (such as “Slab Length: 100, Width: 100, Height: 10”, or “Hole Cbore/Csink Diameter: 12, Diameter 10”.) When the scaling handles are active, the tool tips display the number of the scale handle (such as “Scale Handle: 3”).


The Features Toolbox


Feature solid tools typically have many options.

Cut Feature tool

Used to place a cut in a feature‐based solid, using 1 of the following as a cutting profile:

• A profile element in the design, or a parametric profile created with one of the DD Design tools.

• Surfaces B‐spline surfaces.

• A cell or dimension‐driven cell in the attached cell library, or another instance of one that is in the active design.

In addition:

• Cutting profiles may be open or closed elements.

• When an open profile does not extend to the edge of the feature‐based solid it is extended tangentially to its end point, until it intercepts the edge of the solid.

• Cutting profiles need not be coincident with the feature‐based solid on which the cut is made.

• To delete cuts, use the Delete Feature tool.

• To edit cuts, use the Modify Parametric Solid or Feature tool, or edit within the Feature Manager. Editing an existing cut allows you to change the parameters used to construct it initially.

• You can edit cuts with the Element Selection tool.

• With a dimension‐driven profile, use the Modify Profile tool to modify the shape of the cut.

Exercise: Using the Cut Feature tool with Thickness

1 Continuing in Feature_create.dgn, open the model 06_Features 1.

2 Select Cut Feature (S + 5) with the following tool settings:

Cut Method: Inside Profile



Both Directions: Enabled

Through: Blind

Distance: 10

Back Through: Blind

Back Distance: 10

Thickness: ‐75


The negative value makes the thickness apply to the inside of the profile.


4 Identify the rectangular cutting profile.

5 Position the pointer so that the direction arrow for the cut is downward and accept with a data point, to view the construction.


The cut was created with a thickness (75mm) applied to the inside of the profile. This caused a 75mm wide cut to be created.

7 Undo and try different Cut Solid tool settings.

8 Edit the cuts with the Element Selection tool.



Sweep Edge Feature tool

In the previous exercise, you could have created the same cut with the Sweep Edge Feature tool, which lets you define a cutting profile and an edge, or a group of edges, to use as a reference path.

Exercise: Using the Sweep Edge Feature tool


This model contains a slab feature and a rectangular profile in place ready to use. The white dashed line is for reference only, showing where the cutting profile was in the previous exercise.

2 Select Sweep Edge Feature (S + 7) with the following tool settings:

Mode: Cut

Method: Selected Edge

Thickness: 0



4 Identify the rectangle.

5 Use Ctrl data points to identify the outer top edge of the solid so that they are all highlighted.

6 Accept to view the construction, and again to complete.



If edges are tangentially continuous, you can enable Add Smooth Edges to include all connected portions.

Exercise: Sweep Edge with smooth edges


2 Select Sweep Edge Feature (S + 7) with the following tool setting:

Add Smooth Edges: Enabled


4 Identify the red cutting profile.

5 Identify the top edge of the solid adjacent to the profile.

6 Accept to view the construction and again to complete.

Boss and Protrusion Feature tools

You can add a circular boss or use a profile to add a protrusion.

Exercise: Creating a circular boss


2 Select Boss Feature (S + 4) with the following tool settings:

Direction: Face Normal

Diameter: 50

Height: 100

Round Radius: 5




4 Move the pointer over the solid and see how the boss is shown normal to the nearest face over which the pointer is located.

5 Enter data points to place several bosses at different locations.


7 Click the View Display Mode view control and change the display mode to Smooth.

When adding protrusions, you first construct a profile for the protrusion. Various options are available to determine how the protrusion is added to the solid. In the following example, 6 copies of the solid/profile are present to let you compare various options.

Exercise: Adding a protrusion


2 Select Protrusion Feature (S + 6) with the following tool settings:

Through: Blind

Distance: 150

Back Through: Blind

Back Distance: 150

3 Identify the top left solid.

4 Identify its rectangular profile.



5 Move the pointer so that the arrow points towards the solid and enter a data point.

6 Use the remaining solids/profiles to try the other settings, particularly the options for the Through setting.

Rib Feature tool

Use this to construct a rib between 2 faces of a solid. Tool settings let you choose how the rib is constructed.

• Normal Axis: Sets the direction of the normal to the rib’s surface. Options are Points, or Edge/Face Normal. Points lets you define the rib’s normal by data points, while Edge/Face Normal defines the normal relative to the edge of face on which the rib is placed.

• Thickness: Sets the rib’s thickness (must be greater than zero).

• Draft Angle: Lets you set a taper, from the root of the rib.

• Top and Base Blend Radii: Lets you define blends at the base and/or the top of the rib.

After you have placed the rib, you have the option of using the Modify Parametric Solid or Feature tool to edit its values.

Exercise: Place a rib feature


2 Select Rib Feature (S + 8) with the following tool settings:

Normal Axis: Edge/Face Normal

Thickness: 10



All other settings: 0


4 Snap to the solid and accept to the mid‐point of the top and bottom edges at locations 1 and 2.

5 Move the pointer so that the direction arrow points towards the solid, and accept with a data point to view the rib.


After placing the rib, you can modify it. You will add rounding to its base and top.

Exercise: Modify the rib feature

1 Continuing in Feature_create.dgn, in the model 11_Features 6, select Modify Parametric Solid Or Feature (F + 1).

2 Set the following in the Edit Rib dialog set

Top Blend Radius and Base Blend Radius: 5

All other options: Default



3 Click OK to change the rib.

Thin Shell feature

With this tool, you can specify the following.

• Shell Thickness: Default thickness for walls of the solid. Positive values add material to the outside of the original solid, while negative values remove material from inside the original solid.

• Face Thickness: Lets you define values for 1 or more walls that differ from the Shell Thickness. Entering a Wall Thickness of zero removes the face entirely.

In the following exercise, you will shell out the solid and remove the front face. You will specify that the vertical walls are 5mm (Shell Thickness), while the Top and Bottom faces will be defined as 2mm and 10mm thick respectively (Face Thickness).

When you need to identify a face that is behind another in a view, such as the bottom face in this example, you simply place the pointer over the required surface and select with a data point, or Ctrl data point, and then reset to highlight the face behind.



Exercise: Thin Shelling a solid


2 Select Thin Shell Feature (S + 9) with the following tool settings:

Shell Thickness: 5

Face Thickness: 2


4 Select the top face at location 1 with a data point.

The face highlights and the face thickness (2.00) value displays.


Face Thickness: 10

6 Select the bottom face at location 2 with a Ctrl data point.

The face nearest you in the view highlights, with the Face Thickness value (10.00) displayed.


Face Thickness: 0

8 Select the front face at location 3 with a Ctrl data point.

9 Enter a data point to view the construction, then another to accept.


Modeling Methods


Smooth rendered view of the thin‐shelled solid, showing the difference in thicknesses between the wall thickness and the thickness of the Top and Bottom faces

Modeling Methods

In many cases, a particular operation can be accomplished in a number of ways. One thing you should consider when modeling is how different elements will react if you need to modify parts of the solid.

You will examine an example that uses protrusions and bosses. Both of these features could be constructed with other tools, such as Extrude Feature, and then a boolean Union Feature. The following exercise will show what can happen when you modify solids that have other features applied to them.

Exercise: Effect of modifying a solid


This simple solid consists of a slab feature to which various features have been added:

On the left are 2 red features, a round feature consisting of a cylinder joined to the slab with a boolean union, and then a blend applied at the


Modeling Methods

joining edge. The rectangular (red) feature is an extrusion that has been joined to the slab with a boolean union.

On the right are 2 green features, a boss feature and a protrusion feature. Reduce the height of the slab and see what happens.

2 Select Modify Parametric Solid Or Feature with the following tool setting:

Edit Solids About ID Point: Enabled

You want the slab to be modified relative to the bottom face.

3 Identify the slab at one of its lower edges and accept with a data point.

4 Change the Height to 5.

5 Click OK.

6 Use the Front View and Right View viewing tools to inspect the solid.

The 2 red features no longer are connected to the slab. Still they are part of the overall solid, but they have not retained contact with the surface of the slab. Because these features were created as separate items, a cylinder and an extrusion, they retain the values used to create them in the first place.

Both the green features have maintained contact with the slab feature. The boss is a feature that is applied to a face of a solid, so it moves with the face. The protrusion was created to extend to the face of the solid, so if the face moves, the protrusion is adjusted to maintain contact.



Module Review

Module Review


Questions

1 When working with feature‐based solids, what setting determines the largest single feature‐based solid that can be created in a model?

2 What can you do if you inadvertently select an edge or face that is undesired?

3 Name 2 ways to modify a feature‐based solid.

4 What operations can you perform using handle at the center of a feature when modifying?

5 What is the first thing you do when adding protrusions?

Answers

1 The Solids setting in the Working Areas section of the DGN File Settings dialog’s Advanced Unit Settings dialog (Settings > Design File, Working Units category) determines the largest single feature‐based solid that can be created in a model.

2 Reset until the desired one is selected.

3 You can modify them using the parameters used to create them, or you can modify them interactively, similar to 2D elements.

4 Move it with a data point or copy it with a Ctrl data point.

5 Construct a profile for the protrusion.


Advanced Feature Modeling

Module Overview

When you modify the size of a solid that contains holes, the position of the holes remains static. If you adjust the size so that the solid does not encompass the area in which the holes are located, they disappear. You could move the holes prior to adjusting the underlying solid, but it is much better if this type of procedure is automated.


• Basic knowledge of Feature Modeling

Module Objectives


• Use Dimension Driven Design

• Use advanced functions of Feature Modeling

Feb-09 277 Advanced Feature Modeling





Questions

1 When working with feature‐based solids, what setting determines the largest single feature‐based solid that can be created in a model?


Answers

1 When working with feature‐based solids, the Solids setting in the Working Areas section of the DGN File Settings dialog’s Advanced Unit Settings dialog (Settings > Design File, Working Units category) determines the largest single feature‐based solid that can be created in a model.

2 You can modify them using the parameters used to create them, or you can modify them interactively (with handles), similar to 2D elements.

Dimension Driven Design

Dimension Driven Design or DDD is the ability to use a predefined geometrically‐constrained profile to spawn many other designs. Dimension‐driven design (DDD) is the process by which elements are drawn with respect to previously determined dimensions, and/or relationships between dimensions.

You may have a rectangular element in which you want the width to always be half the length. You can create a dimension‐driven cell, with this constraint defined. When you place the cell, you need only define the length and the width is determined from the constraint formula. Similarly, when you use the DDD tools to modify the length, the width also is modified to maintain the relationship

Advanced Feature Modeling 278 Feb-09Copyright © 2009 Bentley Systems, Incorporated


The Purpose of Dimension‐Driven Design

Very often you find yourself recreating a drawing feature with only slightly different dimensions than the last time you created it. You may even reproduce it more than once at different dimensions, depending on other elements in the design. To save time in this situation, MicroStation provides a form of variational geometry called Dimension‐Driven Design.

Based on constraints defined in the profile structure, MicroStation can automatically update this kind of design to fit dimensional changes initiated by the designer. In this way, designers can create whole families of parts (2D or 3D) from 1 basic profile. This eliminates the duplication associated with traditional techniques.

One profile can create a family of parts by modifying the right dimensions

How does it work?

Traditionally, the elements you draw in MicroStation are dimensionally controlled by attributes of the element itself. Dimensions are associated to the element. However, you can associate elements to dimensions.

By changing a dimension value (text) the element is adjusted to maintain its relationship to the updated dimension value. Dimensions can even have relationships to other dimensions using equations or algorithms. You can store these dimensions and their associated elements as cells to be used over and over

Feb-09 279 Advanced Feature ModelingCopyright © 2009 Bentley Systems, Incorporated


again. Each time you use this cell or profile you can create a new design by simply changing the dimensional values within it.

It is important to understand the terms and concepts associated with the dimension‐driven design process.

Glossary of terms

• Constraint ‐ a piece of information that limits or controls a construction. This can be a Geometric (parallel, perpendicular, etc.), Locational (intersection, midpoint, etc.), Dimensional (2", 4.525"), or Algebraic (h=w*2) control.

• Construction ‐ an element (point, line, circle, ellipse, or B‐Spline curve) that lets constraints locate, delimit or arrange other elements. For example, a construction line can be the center line of a symmetric design. Constructions carry the class attribute by the same name and can be toggled using the Constructions view attribute.



• Under‐constrained ‐ a condition that describes a set of constructions that is not completely defined by constraints. An under‐constrained construction has many possible “solutions” and is usually unacceptably ambiguous.

• Well‐constrained ‐ a condition that describes a set of constructions that is completely defined by constraints or is constant and has no redundant constraints. This is the desired condition when creating profiles as it leaves no ambiguous movement within the set of constructions.

• Over‐constrained ‐ a non desirable condition that describes a set of constructions that has 1 or more redundant constraints. A redundant constraint may or may not be inconsistent with other constraints, but in either case, it adds no useful information.

• Degrees of freedom ‐ the number of movements left unconstrained in a profile and is usually referred to as DOF.

• Solve ‐ to analyze the existing constraints, recalculate any constraint changes, and rebuild the profile using the new values. As a result of re‐solving constraints, degrees of freedom are recalculated and displayed for reference.

The process is as follows:

1. Draw graphics to represent the profile using the dimensions that are most likely to be final.

2. Convert the graphics to a constrained profile using the Convert Element to Profile tool or Constrain Elements tool.

3. Add any necessary dimensions and equations to fully constrain the profile.

4. Re‐solve the profile to check for DOF.

5. If DOF is not equal to zero then add or modify the Geometric and/or Locational constraints.

6. If DOF equals zero then add to cell library as a dimension driven cell.

Dimension Driven Design task

The DD Design task contains tools for creating and modifying dimension‐driven profiles and cells plus dimensioning tools.



Each tool is the top tool in a sub task.

Profile

Parameter Constraints

Attach Element

Geometric Constraints

Evaluate Constraints

Modify Constraints

Your ability to create useful and predictable dimension‐driven profiles will largely be determined by your understanding of constraint geometry. Since constraints are so fundamental to success, you’ll focus on the types of constraints, adding constraints, and Degrees of Freedom (DOF).

Geometric constraints

A Geometric constraint establishes some relationship between drawing elements. This might be a specific angle, or perpendicularity between 2 lines, a tangent relationship between 2 circles, or it might fix an intersection between 2 lines. When a Geometric constraint is applied, MicroStation places a symbol



representing the constraint graphically. The size of these symbols is controlled by the active text style size.

The most useful tool is the first, Constrain Element. It is used to apply tangent, perpendicular, parallel, or fix angle constraints to profile geometry. The tool settings are:

• Method: Sets the method by which to constrain profile geometry.

Smart Constrain Elements — Constrains constructions tangent, perpendicular, or parallel, or by fixing the angle, depending upon the identified element(s) and the number of data points. This Method is recommended unless you need to override or force constraints.

Constrain Two Constructions to be Tangent — Constrains 2 constructions (2 circles, 2 ellipses, a circle or ellipse and a line) to be tangent at as many points as their geometry makes possible.

Constrain Two Lines to be Perpendicular — Constrains 2 lines (or the primary axes of 2 ellipses) to be at a right angle (90°) to one another.

Constrain Two Lines to be Parallel — Constrains 2 lines (or the primary axes of 2 ellipses) to the same rotation angle.

Fix Angle of Line or Ellipse — Constrains a line's orientation or an ellipse's rotation angle.

• Fix Angle Snap Tolerance: (Method set to Smart Constrain Elements only) Sets the tolerance for constraining a line or the primary axes of an ellipse (that is on an angle) to the closest view axis (x‐ or y‐).

Used in conjunction with the Smart Constrain Elements method, this setting forces individually selected elements to be constrained to the view x‐ or y‐axis if the current position of the element is within the tolerance value from a vertical or horizontal position.

For example, if Fix Angle Snap Tolerance is 10° and a single line drawn at 45° is identified, the line is fixed at 45°. If the line was placed at a 5° slope off the view x‐axis, the line is forced to be horizontal.

This setting also forces multiple elements to be constrained parallel, perpendicular, or tangent with one another along the view x‐ and y‐ axes if the current position of the elements are within the tolerance value from a vertical or horizontal position.



• Angle Lock: (Method set to Fix Angle of Line or Ellipse only) Constrains a line or the primary axes of an ellipse by the following options.

None — Geometry is constrained at the angle it was created.

Horizontal — Geometry is constrained to the view x‐axis.

Vertical — Geometry is constrained to the view y‐axis

SettingsToggles the display of the Convert to Constructions and Join Ends at Junctions check boxes.

• Convert to Constructions: Converts primary elements to construction elements.

• Join Ends at Junctions: Extends primary elements to intersection.

In the following exercise you will take a MicroStation block element that has associated dimensions placed, and convert it to a dimension driven profile. You can create profiles directly in cell library files.

Variable names may have up to 32 characters, with no embedded blanks. They are case sensitive and must begin with a letter, followed by letters, numbers, or underscores

Exercise: Basic Dimension Driven Design


User: untitled


2 Open Feature_advanced.dgn.

3 Open the model 01_DDD Constraint 1.

4 Make the Feature Based Solids Modeling tasks active in the Task Navigation dialog.

5 Select Constrain Elements (W + 2 + 1) with the following tool settings:

Method: Constrain Two Lines to be Perpendicular

Join Ends at Junctions: Enabled



6 Select the top edge of the block and then the left edge.

A perpendicular constraint appears.

7 Using the same tool settings, select the left edge and the bottom edge.

8 Select the right edge and the bottom edge.

Three perpendicular constraints for the block.

9 Select Tools > Parametrics > DD Design > Parameter Constraints > Convert Dimension to Constraint and select the top dimension.

10 In the parameter dialog, type the name Length.

11 Convert the vertical dimension and name it Height.

12 Select Modify Constraint (W + 3+ 2) and select one of the dimensions.


Constraints and Feature Modeling

13 Edit the value of the dimension in the tool settings.

Note: Additional DDD examples are in the DDD Extra models.


In many cases, features such as holes must retain a particular relationship to an edge, or a vertex, of a solid. You apply constraints to 4 countersunk holes to force them to stay concentric with the corner blend of an underlying slab feature. With the constraints in place, any changes you make to the size of the underlying slab, or to the radii of the corner blends, will result in a repositioning of the holes to maintain their constraint values.

Constrain Feature

Used to parametrically locate features within a solid, and to modify previously established constraints settings.

Features that can be constrained include holes, bosses, cuts, and protrusions. In the case of cuts, you can constrain the depth of the cut, as well as its location on the face of the solid. Profile features (cuts and protrusions), holes, bosses, and ribs can be constrained to edges, vertices, and faces of a solid.

Features can be located relative to vertices on the solid, another (previously placed) feature on the solid, or an edge, plane, or line.



When locating a feature relative to another feature, the direction of the x, y, and z axes of the coordinate system that appears is relative to the direction that the original solid was created.

Tool Setting Effect

Add New Constraints

Adds a constraint

Modify Existing Constraints

Edit existing constraint

Type of Constraint

Distance ‐ Lets you locate a feature, or a Dimension Driven profile at a specified distance from another feature. Distances may be set between:• parallel edges• edge and a vertex• vertex and edge• holes, bosses, ribs• other combinations of these entities and features.

Edges must be parallel, otherwise they cannot be selected. If the edges are not parallel, they must first be constrained with the Parallel constraint.

Angle Lets you specify an angle between linear elements of a profile feature and another feature.Angles are in degrees.

Concentric makes 2 point‐like entities concentric. This works on vertices of a profile as well as on holes and bosses.

Perpendicular makes 2 edges perpendicular.

Parallel makes 2 linear edges parallel.Plane Distance lets you constrain the plane of a profile or hole/boss to be parallel to and at a distance from a planar face on the solid.

Plane Angle constrains the plane normal to a profile, hole, boss to be at an angle from the other specified plane.

Feature‐Feature places this feature the specified X, Y, and Z distance from the specified feature location.

Distance Lets you define the distance of the constraint

Angle Lets you define the angle of the constraint

X Delta, YDelta, Z Delta

Feature‐Feature only. Lets you define the distance change in x‐, y‐ and z.



Exercise: Add concentric constraints

1 Continuing in Feature_advanced.dgn, open the model 02_Constraint 1.

2 From the Manipulate Feature toolbox, select Constrain Feature (G + 5).

3 Make sure Add New Constraints icon is enabled.

The Add New Constraints tool has a number of options that you set using icons.

4 In the tool settings, click the Concentric icon.

5 Identify the hole in the lower center.

6 Identify the arc of the corner rounding at location 2.

A concentric constraint graphic appears at the center of the arc, showing the point to which the center of the hole will be placed.

7 Accept to view the new position of the hole.

Equation Icon Distance and Angle settings only. Located adjacent to the Distance or Angle setting and is enabled prior to accepting the value. Opens a dialog that optionally lets you define each setting with variables. For more information, see Variable Driven Modeling and Constraints.

Treat DD profiles as Rigid

If on, dimension driven profiles are treated as rigid profiles, and their dimensions may not be modified to change the shape of the profile and the generated solid.If off, dimension driven profiles may be modified to change their shape, and that of the generated solid.

Tool Setting Effect



8 Accept to complete the operation.

9 Repeat the previous steps for the 3 remaining holes, constraining them to be concentric with the rounding on the 3 remaining corners of the solid.

When holes are constrained, whenever you make a change to the solid that causes the center of the corner rounding to move, the hole will move also.

Exercise: Modifying a solid with constrained features

1 Continuing in Feature_advanced.dgn, open the model 03_Constraint 2.

This is a completed version of the model from the previous exercise.

2 Select Modify Parametric Solid Or Feature (Z + 1).

3 Identify the rounding on the corners at location one and accept with a data point.

The Edit Edge Blend dialog appears, with the current settings for the selected blend feature.



4 Change the Start Radius value to 25 and click OK.

All of the holes have shifted slightly to maintain the concentric constraint with the edge rounding.

5 Identify the solid at location 2 and accept with a data point.

The Edit Slab dialog appears, with the current values for the slab.

6 Change the Length value to 75 and click OK.

The holes shift to maintain their constrained position.

After modifying the solid, the holes still maintain their concentric position relative to the rounding on the corners, due to the concentric constraint.


The Feature Manager

The Feature Manager

This tool lets you inspect the structure of any feature solids using a feature tree. It also lets you perform various manipulations of the features. In the Feature Manager dialog, all features of a solid are displayed as branches on a tree view, in the order in which they were added to the solid. You can:

• Identify features

• Analyze features

• Modify features

• Suppress features

• Temporarily suppress the display of features

• Re‐order features in the feature tree

The dialog can be opened from the Feature Modeling Primary toolbox and can be docked to the left or right of the screen. The dialog can also be opened from the menu bar Element > Feature Modeling > Feature Manager.

Working with Feature Manager

You can display a feature tree of a selected solid and identify, analyze, modify, suppress, or re‐order features in the feature tree. You can discover how a solid was created and you can display the solid at any stage in its construction.

Use Feature Manager when an underlying feature has none of its edges showing and you cannot identify it graphically. This can happen, for example, if a slab has all its edges rounded with blends. In these instances, use Feature Manager to identify the underlying slab feature for manipulation or modification. When you select a solid or one of its features in Feature Manager, the selected item is highlighted in the model view(s).

Exercise: Open Feature Manager

1 Continuing in Feature_advanced.dgn, open the model 04_Feature Manager 1.

2 Select menu item Element > Feature Modeling > Feature Manager.

You can dock both the toolbox and the Feature Manager dialog.

3 Identify the solid to view its feature tree.


The Feature Manager

4 Left click on various items in the feature tree and note that the selected feature highlights in the view.

Viewing a solid at various construction stages

Often, feature solids consist of 1 or more underlying solids to which various features have been added. Using Feature Manager, you can roll back the display of the solid to its state at a particular feature, using the Display Geometry at Feature command. This is a temporary display only, and a data point returns the display to the current state of the feature solid.

Exercise: View the solid at various stages of its construction

1 Continuing in Feature_advanced.dgn, in the model 04_Feature Manager 1, right click on the entry Union Solids (6) in the Feature Manager dialog.

2 In the menu that opens, select Display > Geometry At Feature.

3 Enter a data point to cancel the display.

4 Repeat for other features in the feature tree.

Controlling the display of features

Sometimes you may want to look at a simplified version of a design without some of the finishing touches (features) displayed. This may be to help in making adjustments to the underlying solids. Feature Manager lets you toggle the display of selected features. You can select to suppress display of features as follows.

• By Instance: Suppresses only the selected feature.

• By Type: Suppresses all of selected type within specified dimension range.


The Feature Manager

• All Above Feature: All features above the selected feature in the feature tree.

When features are suppressed, they appear grayed out in the feature tree.

Exercise: Suppressing features

1 Continuing in Feature_advanced.dgn, in the model 04_Feature Manager 1, select the left countersunk hole in the view (Hole (8)).

The feature highlights in the Feature Manager dialog.

2 Right click on the highlighted feature in the Feature Manager dialog and select Suppress Feature > By Instance.

The hole disappears from the solid in the view and its entry in the feature tree is greyed out.

3 Right click on the grayed out feature in the feature tree and again select Suppress Feature > By Instance to cancel the suppression.

4 Right click on any of the hole features in the feature tree and select Suppress Feature > By Type.

5 In the Feature Type Suppression dialog, set the following:

Suppress Feature Type: Enabled

Compare Using: Greater Than

Hole Diameter: 0

6 Click OK.

The countersunk holes disappear from view, as do the hinge pin holes. You instructed the system to suppress display of all holes with a diameter greater than zero. In other words, every hole.


The Feature Manager

Once you have seen whatever was required, you can simply disable the suppression of the features, so that they again display in the solid.

7 In the feature tree, right click on any of the grayed out hole features and select Suppress Feature > By Type.

8 Disable Suppress Feature Type in the dialog and click OK.

You can suppress all features above a selected feature. This can be useful in working with underlying solids.

Exercise: Suppressing features above a selected feature

1 Continuing in Feature_advanced.dgn, in the model 04_Feature Manager 1, in the feature tree, right click on Union Solids (6), and select Suppress Feature > All Above Feature.

All features above the selected one are grayed out and they have disappeared from the solid in the view.

2 To remove the suppression, right click on the topmost feature in the feature tree, Edge Blend (14), and select Suppress Feature > All Above Feature.

Rearranging feature order

As you add features to a solid, they appear at the top of the feature tree. Typically, features only know about those features that are below them in the tree. If this causes a problem with an operation you can rearrange features in the feature tree.


The Feature Manager

Exercise: Inspect the feature trees for both solids

1 Continuing in Feature_advanced.dgn, open the model 05_Feature Manager 2.

In this example, both solids look identical. They were created from a union of 2 slabs, with a through hole and several blends. When the features are inspected, however, you will see that there are differences.

2 Select the Feature Manager menu item (Element > Feature Modeling > Feature Manager).

3 Identify the countersunk hole in the yellow solid (on the left).

The hole feature, Hole (3), is located above Slab (2), but lower than the Union of the slabs, Union Solids (4). In other words, it only knows about Slab (2), the slab in which it was placed originally.

4 Identify the countersunk hole in the green solid (on the right).

This time that the hole feature, Hole (4), is located above the Union of the slabs, Union Solids (3). In other words, in this solid it knows about both slabs below it in the feature tree.

In these solids, the difference is because in the yellow solid the hole was placed in 1 of the underlying slabs prior to the creation of the union. In the green solid, the hole was placed after the 2 slabs had been merged into 1. Wherever you move the hole in the left solid, it will only ever pass through the top part of the solid (the first slab), while moving the hole in the green solid will always result in the hole passing through both of the original slabs.

Exercise: Move the hole in both solids

1 Continuing in Feature_advanced.dgn, in the model 05_Feature Manager 2, select the Move Feature tool with the following tool setting:

Make Copy: Disabled


The Feature Manager

2 In the yellow solid, identify the hole.

3 Using AccuDraw, move the hole ‐100mm along the x‐axis (to the left).

Even though the hole is a through hole, it still only penetrates the height of the top slab of the union.

4 Repeat for the hole in the green solid.

This hole penetrates through both slabs of the union.

The hole in the solid on the left penetrates only the first slab, while that in the solid on the right penetrates both slabs of the union

Assuming that you really want the hole to pass through the entire solid, you can fix the problem by deleting the hole and recreating it, or you can simply move it up higher in the feature tree. In this case, you want to move the hole feature to a position above the Union Solids (4) feature.

Exercise: Move the feature in the feature tree

1 Continuing in Feature_advanced.dgn, in the model 05_Feature Manager 2, select the Feature Manager tool.

2 Identify the short hole in the yellow solid.


Variable Driven Modeling

3 In the Feature Manager dialog, right click on the highlighted feature and select Re‐order Tree > Mark For Move.

The feature to be moved highlights.

4 Right click on the Union Solids (4) feature and select Re‐order Tree > Insert Marked Above.

The Hole (3) feature now is above the Union Solids (4) feature in the feature tree. In the view, the hole passes through the entire solid.


MicroStation's Variable Driven Modeling (VDM) tools let you assign variables or equations to the parameters of solids and features contained in your models. Variables may contain simple values, or equations that define a value. Equations also may include previously defined variables.

Many of the settings for features have an equation icon, signifying that you can assign a variable, or an equation, to the particular setting.

Equation icon



Working in conjunction with the variable driven modeling tools, the Constrain Feature tool lets you constrain a feature of a solid with variables.

While each dimension for a feature can be edited individually, other options let you use variables to define dimensions, such that editing a single variable can propagate changes to all solids in the model that use that variable.

By default, each feature is given local variables to define its various parameters. As well, you can create your own global variables, which you may assign to the parameters of a feature.

Taking this further, you can use equations to link dimensions, or variables. For example, you may want the width of a slab to be 1 meter plus one‐fifth of its length, and the Height to be one‐third of the Width. By assigning the appropriate equations to the Width and Height dimensions, only the Length parameter would be available for manual editing, with the remaining 2 dimensions automatically updated as per the equations.

Variables can be divided into 2 categories:

• Global — created manually and available to all solids in the model.

• Local — created by MicroStation automatically, for all feature parameters of a solid, and available for that solid (only).

Variables can be defined as individual values, or they can be defined by equations, which in turn may contain previously defined variables. Equations can include trigonometric and algebraic expressions, giving you a full range of options.

The general process is as follows.

1. Create the variable in the Global Variables dialog.

2. Assign it through the equation icon of a tool.

3. Edit value in Global Variables dialog.

Exercise: Using Global Variables

1 Continuing in Feature_advanced.dgn, open the model 06_Global Variables.

2 Select Element > Feature Modeling > Variables.

There are variables defined in this model for the slab and the thin shell.



3 Click New in the Global Variables dialog and name the new variable: hole_dia.

4 Set the default value of hole_dia to 1 and save it.

5 In the Feature Manager, right click on the Hole feature and select Modify.

6 In the Edit Hole dialog click on the Equations icon next to Diameter and select hole_dia as the variable.

7 Click OK.

8 In the Global Variables dialog change the value of hole_dia from 1 to 2 and click Apply.


Profile-Driven Feature Solids

Feature modeling examples

The Plant Examples data set includes several files with Feature modeling. These are found in \Document and settings\All Users\Application Data\Bentley\Workspace\Projects\Examples\Plant\Cell\

• StructShapes.cel

• Ladder.cel

• Equipmentprofiles.cel

• HardwareParts.cel

Profile‐Driven Feature Solids

Feature modeling tools let you create feature solids from profile elements in a variety of ways. Methods include:

• Extruding or revolving a closed profile element

• Extruding a closed profile along a path element

• Using the Skin Solid Feature tool to create a solid from 2 or more profile elements

When you create a feature‐based solid from a profile element, you have the option of later modifying or replacing the profile element to change the shape of the solid. You can do this using the Modify Profile tool, or you can work with the profile interactively after selecting the solid with Element Selection. If the profile is a fully‐dimensioned dimension driven design (DDD) profile, you have the ability to edit its dimensions. Additionally, you have the editing functions available using the Modify Parametric Solid Or Feature tool. This can be used to edit the value of the extruded distance for extruded solids, or for changing and specifying a thickness for hollow extrusions.



Creating profile‐driven feature solids

Tools for creating profile‐driven feature solids are located in the Profile Feature Solids toolbox. Feature‐based solids can be edited after placement. This is true even if they have been merged with other feature solids.

Extruded and Revolved features

Like other feature solids, the solids created with the Extrude Feature and Revolve Feature tools are editable.

Exercise: Create an extruded feature

1 Continuing in Feature_advanced.dgn, open the model 07_Profiles 1.

2 Select Extrude Feature (A + 1) with the following tool settings:

Distance: 200

All other settings: Disabled and other values 0

3 Identify the profile on the left, in the view.

4 Move the pointer to the right to define the direction, and accept with a data point.

Exercise: Create a revolved feature

1 Continuing in Feature_advanced.dgn, in the model 07_Profiles 1, select Revolve Feature with the following tool settings:

Revolve Axis: Vertical



Angle: Enabled and set to 180

Radius: Enabled and set to 50

All other settings: Disabled and other values 0

2 Identify the profile on the right, at location 1.

3 Move the pointer to the left and accept with a data point.

4 Move the pointer upward to define the direction of rotation and accept with a data point.

When the solid that you want to create should be hollow, specify a wall thickness for the extrusion. When defining the Thickness setting, a positive figure adds thickness outside the profile shape, while a negative figure adds thickness inside the profile shape.

Exercise: Create hollow extrusions/revolutions


2 Create an extrusion and a revolved solid as before, but with the Thickness setting at 3mm.

The solids are hollow, with walls at the specified thickness this time.




Use the view rotation tools in the toolbox to select standard views, and the Rotate View view control to interactively rotate the view to inspect the solids.

Tube Feature

The Tube Feature tool lets you extrude a profile along a path element. The profile can be an existing element or cell.

Exercise: Creating tube features


2 Select Tube Feature (A + 3), with the following tool setting:

Thickness: 0

3 Identify the yellow ellipse path element on the right.

4 Identify the orange profile element attached to the path element.


6 Set Thickness to 5.

7 Identify the red path element on the left.

8 Identify the green profile element.




Skin Solid Feature

Used to construct a solid, or surface, using 2 or more section profiles to define the shape. Once the solid has been created, you can use the Move Feature tool to move any of the section profiles to reshape the solid. You can modify the shape of 1 or more profiles again to change the shape of the solid.

Where more than 2 profiles are used in the construction, use Ctrl data points to select the profiles, or you can use Element Selection or Power Selector to select the profiles.

Exercise: Create a Skin Solid Feature


2 Select Skin Solid Feature (A + 4), with the following tool setting:

Thickness: 10

3 Select Element Selection (1), with the following tool settings:

Method: Line

Mode: Add

4 Draw a line through the 5 profiles, so that they all highlight.

5 Select Skin Solid Feature.




Helix Feature

Using this tool, you can create a helical‐shaped feature solid, by sweeping a selected profile element or cell along a helical curve. Tool settings let you define the height, radius, and pitch. You can define a right or left thread and whether or not the pitch is variable. The amount of variation in the pitch is determined by the radius of the helix.

Exercise: Create a helix feature


This model shows a Front view of a ramp profile.

2 Select Helix Feature (A + 5), with the following tool settings:

Thread: Right

Pitch: Constant

Height: 4

Top and Bottom Radius: 5

Helical Pitch: 4

3 Identify the profile at its left edge.

4 Move the pointer to the left and, with it indexed to AccuDraw’s x‐axis, enter a data point to define the direction of the bottom radius.

5 Move the pointer upward and enter a data point to define the height.

6 Enter a data point to accept the top radius.



7 Accept again to complete the construction.

8 Rotate the view to see the result.

Thicken Feature

This tool adds thickness to a surface to create a solid. The Thickness setting lets you define the amount of the thickening. The Apply To setting lets you define which side of the surface that the thickening is placed.

• Side One: The side from which the surface normals point outward. You can use the Change Normal Direction tool in the Modify Surfaces toolbox to check or change surface normals direction.

• Side Two: The reverse side to side 1.

• Both Sides: Thickening is applied to both sides of the surface.

When you apply thickening to a surface, it becomes a feature solid.

Exercise: Add thickness to a surface


2 Select the Thicken Feature tool with the following tool settings.

Apply To: Both Sides

Thickness: 5

3 Identify the surface.



4 Accept to add the thickening.

Modifying profile‐driven feature solids

Next, you will use the Modify Profile tool to change the shape of a profile used to generate a solid. You will see that this updates the solid to conform to the new shape of the profile. When modifying profiles, you can use the Modify Profile tool or you can make the modification interactively.

Exercise: Modify the profile of the extruded feature solid

1 Continuing in Feature_advanced.dgn, open the model 13_Profiles Modify 1.

2 Select Modify Profile (Z + 2) with the following tool settings,

Extract Profile

Interactive Positioning: Disabled

3 Identify the extruded feature and accept with a data point.

The profile displays, and the solid is temporarily converted to a construction class element. If Constructions are on, the solid appears as dashed lines.

4 Open the View Attributes dialog and toggle Constructions to disable display of construction elements.



5 Select Modify Element (7 + 1) to thicken the vertical leg of the profile 50mm to the left, and the right side of the horizontal leg downward by 50mm.

6 Open the View Attributes dialog and toggle Constructions to display the extruded solid.

7 Select Modify Profile, which now defaults to Replace Profile in the tool settings.

8 Identify the feature (shown dashed).

9 Identify the modified profile (shown solid).

10 Accept to complete the modification.



The solid is regenerated to reflect the shape of the modified profile.

When you want to modify the distance of an extrusion, you can use the Modify Parametric Solid Or Feature tool.

Exercise: Modify the extrusion distance of a feature solid

1 Continuing in Feature_advanced.dgn, in the model 13_Profiles Modify 1, select the Modify Parametric Solid Or Feature tool.

2 Identify the solid and accept with a data point to open the Edit Extrusion dialog.

3 Change the Distance to 300 and click OK.

Similarly, if you wanted to change the extrusion from solid to hollow, you could use the Modify Parametric Solid Or Feature tool to add a thickness value to the walls of the extrusion.

You can change the shape of the profile and other settings, such as the distance of the extrusion with this method.

Exercise: Interactively modify the solid


2 Use Element Selection (1) to select the extruded solid.

Handles appear at the ID point and at each vertex of the profile shape. They are also at the beginning and end points defining the distance of the extrusion. At the moving handle, a graphic indicates the x, y, and z directions of the extrusion.

3 With the Element Selection tool still active, use Ctrl data points to select the 2 handles at locations 1 and 2.



When selected, the handles change color from blue to yellow.

4 With AccuDraw active, click on either of the highlighted handles and use AccuDraw to move them 50mm to the left.

5 With the Element Selection tool still active and the solid still highlighted, use Ctrl data points to select the 2 handles at locations 3 and 4.

6 Click on either highlighted handle and use AccuDraw to move them 50mm downwards.

7 Still with the Element Selection tool active and the solid highlighted, click on the extrusion handle at location 5.

The AccuDraw compass is positioned back at the plane of the profile and only movement in the extrusion direction is allowed. This lets you use AccuDraw to define a new distance.

8 In AccuDraw’s x field, type 300 and accept with a data point.

9 Enter a data point away from the solid to complete the modifications.

If a solid has been created by extruding a profile along a path, not only can you modify the profile, you can use the same techniques to modify the path element.

Exercise: Modifying a path element


2 Open the View Attributes dialog and toggle display of Construction elements on.

These are the path element and the profile used to construct the solid.

3 Use Element Selection to select the path element at location 1.

4 Select the handle at location 2.

5 Move the handle to modify the path element and enter a data point.



6 The solid updates to reflect the new shape of the path element.

As you can see, feature‐based solids are easy to modify, either with specific tools or interactively.

You have modified an existing profile. Another option is to replace the existing profile with a new one.

Note: When viewing solids created from profiles, if you turn on construction elements in a view, the profiles are displayed as a dashed line.

Exercise: Replace the profile for an extrusion



This model contains a solid created from a profile that was extruded along a path element. Both these elements are represented by the dashed lines in the view. You will replace the existing profile with the red profile.

3 Select Modify Profile (Z + 2), with the following tool setting:

Replace Profile

4 Identify the existing profile at location 1.

5 Identify the new (red) profile at location 2.



6 Accept to make the replacement.

If a solid has been created from multiple profiles, such as with the Skin Solid Feature tool, you can modify or move any of the profiles to edit the feature solid.

Exercise: Modify individual profiles



The original profiles display as dashed lines.

3 Use Element Selection to select the center profile of the solid.

4 Select the move handle (Handle with arrows) for the profile.

This is at the center of the graphics indicating the x, y, and z axes of the profile.

5 Use AccuDraw to move this profile ‐50mm along the x‐axis (to the right in the view.)




Similarly, you can move or modify any of the profiles used to create the feature solid.

When a dimension driven (DD) cell is used as the profile you can edit the values assigned to the DD cell using the Modify Profile tool.

Exercise: Modifying a DD cell profile


2 Select Modify Profile (Z + 2), with the following tool setting:

Modify DD Profile Parameters

3 Identify the solid and accept with a data point.

The Modify Profile dialog appears, displaying the cell in a preview window and containing a list box with the parameters for the DD cell used as a profile.

4 Select Parameter T1 in the list box.

5 In the input field below the list box, change the value from 20 to 50, then enter a data point in the preview window to effect the change.

6 Repeat for the T2 parameter, changing its value to 50.


Modifying Face Features

7 Click OK, to close the dialog and update the solid.


Often you are required to make modifications to a design. The Modify Face Features toolbox contains tools for manipulating and modifying faces of a solid.

Taper Face Feature

This tool lets you add a taper, or draft, to 1 or more faces of a solid. Tapers are constructed relative to the position of the identification point of the solid. Tool settings let you specify the following.

• Draft Direction: Sets the direction of the taper on the face relative to the Screen, Design, or ACS X, Y, or Z direction.

• Draft Angle: Sets the angle of the taper, relative to the Draft Direction. Angles may be positive to taper inwards, or negative to taper outward, from the start point.

• Add Smooth Faces: If on, faces that are connected tangentially to the selected face also are tapered.

Exercise: Tapering face(s) of a solid

1 Continuing in Feature_advanced.dgn, open the model 19_Modify Faces 1.

2 Select the Taper Face Feature tool (F + 1), with the following tool settings:

Direction: Design Z

Draft Angle: 5

Add Smooth Faces: Disabled

3 Identify the (left) solid at location 1.

This determines the point from which the taper will be applied.

4 Identify the face to taper at location 2.

5 Accept to view the taper, and again to complete the construction.

When you enable Add Smooth Faces, all faces that are connected tangentially to the selected face will be included in the taper.

6 In the tool settings, enable Add Smooth Faces.



7 Identify the (right) solid at location 3.

8 Identify the face to taper at location 4.

9 Accept to view the taper, and again to complete the construction.

You can adjust the taper with the Modify Solid or Feature tool. You will increase the taper to 10 degrees.

Exercise: Modify the taper

1 Continuing in Feature_advanced.dgn, in the model 19_Modify Faces 1, select Modify Parametric Solid Or Feature (F + 1).

2 Identify the (left) solid at location 1, to highlight the tapered face.

3 Accept to open the Edit Taper dialog.

4 Change the Draft Angle setting to 10.

5 Click OK.

6 Repeat for the remaining solid.

Extend Face Feature

This tool gives you a range of options for extending a face of a solid. You will work with the simple solid shown.

Exercise: Extending a face of a solid


2 Select Extend Face Feature (F + 2), with the following tool settings:



3 Identify the solid at the left.

4 Identify the top face with a data point so that it is highlighted.

5 Accept to view the construction.

6 Accept again to complete the construction.



7 Repeat the exercise on the next solid, this time with Offset Face enabled.

You can select multiple faces when using this tool. Each selected face will be extended by the same amount.

Exercise: Extend multiple faces

1 Continuing in Feature_advanced.dgn, in the model 20_Modify Faces 2, select Extend Face Feature (F + 2) with the following tool settings:



2 Identify the solid second from right.

3 Use Ctrl data points to select the front face, and the face on the right side of the chamfer, so that all are highlighted.



4 Accept to view the construction and again to complete it.

5 Repeat the exercise on the far right solid, with Offset Face enabled.

Another option is to display the original face position. These are displayed as construction class elements and you can enable them by turning on Show Original Face Position when you extend the face. Or, you can use the Modify Parametric Solid Or Feature tool to turn them on. Constructions Elements must be turned on for the view as well.

Spin Face Feature

As its name suggests, this tool lets you spin a face on a solid. Settings for the tool let you select from the following.

• Revolve Axis: Options are X, Y, or Z axis for Screen, Design, or ACS, or you can set the axis to be Edge Tangent, the direction of the tangent of the selected edge at the point of identification of the solid.

• Angle: Sets the angle through which to spin the face.

• Radius: Sets the radius for the spinning operation.

• Show Original Face Position: If on, the original location of the face is displayed in the form of construction class elements.

When you want to spin the face about an Edge Tangent, the point with which you identify the solid is the edge used for the spin operation.



Exercise: Spin a face on a solid


2 Select the Spin Face Feature tool (F + 3) with the following tool settings:

Revolve Angle: Edge Tangent

Angle: 90

Radius: 0

3 Press <T> to switch to Top rotation.

4 Identify the green solid at location 1.

This will be the edge about which the face will be rotated.

5 Select the end face at location 2 and index to the left with AccuDraw.

6 Accept to view the construction and again to complete it.

7 In the tool settings, set Radius to 40.

8 Repeat the exercise for the red solid.

This time that a radius has been applied to the rotation, from the selected edge.



Remove Face Feature

This tool lets you remove an individual face from a solid. When the setting Add Connected Faces is enabled, then all connected faces are included when you select a face. This tool is useful for removing disjointed parts of a feature solid.

If you extrude multiple shapes in 1 operation, for example, they are a single feature. If you then tried to use the Delete Feature tool to remove 1 of the extrusions, all would be highlighted, as they are a single feature. Using the Remove Face Feature tool, however, lets you remove 1 of the extrusions. Similarly, if you cut through a solid, leaving 2 separate parts, then this tool will let you delete the unwanted portion of the solid.

Replace Surface Feature

This is a good tool for matching other faces of a single solid to the plane, or curve, of an existing face, or to that of a separate element.

Exercise: Replacing surfaces on a solid


2 Select Replace Surface Feature (F + 5), with the following tool setting:

Use Existing Face: Enabled


4 Select the top left face at location 1, as the replacement surface.

5 Use Ctrl+data points to identify the remaining top faces at locations 2 and 3.



6 Accept to view the result, and again to accept the changes.

All top surfaces now align with the one selected first.

7 Repeat the previous steps on the Red solid, this time selecting the rounded top surface at location 1 as the replacement surface.

The curvature of the rounded surface is continued through to the surfaces that have been replaced.

You also have the option of using a separate element to define where the surfaces should be located.

Exercise: Replace surface using a separate element

1 Continuing in Feature_advanced.dgn, in the model 22_Modify Faces 4, and with Replace Surface Feature (F + 4) still active, change the following tool setting:

Use Existing Face: Disabled

2 Identify the cyan solid.

3 Identify the red rectangular surface.

4 Use Ctrl data points to identify the 3 top faces of the solid.



5 Accept to view the result, and again to accept the changes.

Deform Face Key‐in

Using this tool you can interactively change the shape of faces on a solid by pushing and pulling them. You can define which edges/vertices you want to remain as is and you can place a curve element to that you want the face to match. Options available with this tool are:

• Type: Defines how the face is deformed:

• Center Point deforms the face from the center point of the selected face.

• Picked Point deforms the face from the identification point of the selected face.

• Space Curves let you define the deformation with selected curves.

• All Edges/Vertices Fixed: If on, all edges and vertices of the selected face are fixed while the rest of the surface is deformed.

• All Vertices Fixed (Applicable only when All Edges/Vertices Fixed is off): If on, all vertices of the selected face are fixed while the rest of the surface is deformed.

• Smooth Edges (Applicable only when All Edges/Vertices Fixed is off): If on, when you identify an edge to be fixed, all edges that are tangentially continuous also are selected.

Exercise: Deforming a face of a solid


2 You may need to load the 3ddeform.ma from



C:\Program Files\Bentley\MicroStation V8i\MicroStation\mdlsys\asneeded\smartsolid

3 In the Key‐in window, type in: Deform Face

4 Use the following tool settings:

Type: Center Point

All Edges/Vertices Fixed: Enabled

5 Identify the top left (green) solid.

6 Select the top face with a data point.

The pointer now controls a surface element.

7 Move the pointer upward and enter a data point.


9 Click the View Display Mode view control and change the display mode to Wireframe.

The face has deformed, but all edges have remained fixed.

10 Select Deform Face, with the following tool settings:

All Edges/Vertices Fixed: Disabled

All Vertices Fixed: Enable

11 Identify the top right (yellow) solid.

12 Select the top face of the solid.

All 4 vertices of the top face are now highlighted.





15 Click the View Display Mode view control and change the display mode to Smooth, then return to Wireframe.

This time only the vertices remained fixed when the surface deformed.

You can also select which edges or vertices you want to remain fixed.

Exercise: Selecting from a Picked Point

1 Continuing in Feature_advanced.dgn, in model 23_Modify Faces 5, key‐in Deform Face

2 Use the following tool settings:

Type: Picked Point

All other settings disabled.

3 Identify the lower left (red) solid.

4 Select the top face of the solid.

5 Select the right edge at location 1.



6 Use Ctrl data points to select the vertices at location 2 and 3.

When you move the pointer over each vertex, a handle appears to indicate that you can select it.



9 Click the View Display Mode view control, change the display mode to Smooth, and then return it to Wireframe.

Using Picked Point, the point that you use to identify the surface also becomes the point from which the deformation occurs.



Module Review

Module Review


Questions

1 What is Dimension‐driven design?

2 What is a Constraint?

3 What is a Construction?

4 True or False: You can create profiles directly in cell library files.

5 Name three methods to suppress display of features using Feature Manager.

6 For what purpose do you use the Variable Driven Modeling (VDM) tools?

7 What is a Local variable?

8 Name 2 methods of creating feature solids from profile elements.

Answers

1 It is the process by which elements are drawn with respect to previously determined dimensions, and/or relationships between dimensions.

2 An item of information that limits or controls a construction.

3 An element (point, line, circle, ellipse, or B‐Spline curve) that lets constraints locate, delimit, or arrange other elements.

4 True.

5 By Instance: Suppresses only the selected feature. By Type: Suppresses all of selected type within specified dimension range. All Above Feature: All features above the selected feature in the feature tree.

6 To assign variables or equations to the parameters of solids and features.

7 It is a variable that is created by MicroStation automatically, for all feature parameters of a solid, and available for that solid (only).

8 Extruding or revolving a closed profile element. Extruding a closed profile along a path element. Using the Skin Solid Feature tool to create a solid from 2 or more profile elements.


Module Review


Introduction to Surfaces

Module Overview

MicroStation’s surfaces tools let you create and modify both simple and complex surfaces. Surface modeling tools are in the Surface Modeling task,which includes the Create Surfaces, Modify Surfaces, Fillet Surfaces, 3D Query, Mesh and Curve toolboxes.

Surface objects are like balloons. They have an outer boundary, but are empty on the inside. While in Solid modeling, you thought as a sculptor, with Surfaces you must be thinking in profiles or edges. You must find the profile curves that define the edges of your surface. What do they look like? How can I build them? Solving this problem solves many of the 3D surfacing problems.

You can construct a rectangular B‐spline surface with 2 points and more complex B‐spline surfaces by entering a network of points, or by using existing elements in the model. These existing elements may form the edges of the surface, or you may sweep 1 element (curve) along 2 other elements (traces). You can create other surfaces from a network of elements, or by a number of sections. Additionally, you can create a helical surface by sweeping a profile along a helix, or create a surface that is offset from an existing surface.

Example of a helical surface, surface by section and free‐form surface

Feb-09 327 Introduction to Surfaces





• Knowledge of 3D View Control

• Knowledge of B‐Spline Curves

Module Objectives


• Recognize the value of NURBS Surfaces

• Modify a NURBS Surface



Questions


2 True or False: When you use key‐ins, or use the view rotation tools from the toolbox, the tool applies to the active view.

Answers


2 True.

Introduction to Surfaces 328 Feb-09Copyright © 2009 Bentley Systems, Incorporated

B-spline Surfaces

B‐spline Surfaces

Free‐form surfaces, or NURBS surfaces, are the most flexible of all surfaces. NURBS stands for Non‐Uniform Rational Basis Spline. They use a basis function to mathematically determine the curve or surface. The 3 advantages are as follows.

• B‐splines are locally controllable. You can edit a small portion of the surface without changing the rest of the surface. For example, if you were modeling a human face, you could change the size of the nose without affecting the shape of the cheeks.

• B‐splines have no resolution. You can zoom in very close to the surface and it still looks smooth, not faceted.

• B‐splines are efficient. B‐splines are calculated surfaces so you do not need to store as many points as you would if you used a Mesh surface.

These surfaces can be used to model the most complex of surfaces, such as the human body, the surface of an aircraft wing, a double‐curved roof, the hull of a ship, and many other things.

As with B‐spline curves, B‐spline surfaces have a control polygon, sometimes called a control net, which determines their shape. You can modify a B‐spline surface by changing the control points, or poles, which make up the control polygon of the surface. These poles are located in the U and V direction, which are 2 directions that define the number of points in each row (U) and column (V) of the control polygon. The order of the B‐spline surface in each direction sets the minimum number of points required to define each row or column of the control polygon.

Much of your work with surfaces will involve B‐spline surfaces. When you create a B‐spline surface, you can choose whether the control polygon is visible. Visible or not, you still can modify a B‐spline surface since when you identify it, the control polygon displays. Additionally, you can enable display of the control polygon when needed.

In the following exercise, the model contains a rectangular shape, but it is not a standard block. It is a B‐spline surface, placed with the Create Planar Surface tool. It has been set to display extra rule lines to help you visualize the surface as you modify it.

Exercise: Modify a B‐spline surface


User: untitled

Feb-09 329 Introduction to SurfacesCopyright © 2009 Bentley Systems, Incorporated

B-spline Surfaces


2 Open Surfaces.dgn from the class data set.

3 Open the model 01_Modify Surface.

4 Select Modify Element (7 + 1) from the Main toolbox.

5 In the Isometric view, snap to the surface at lower left corner and accept with a data point.

Lines and points display to represent the control net for the B‐spline surface. Note that the pointer controls the shape of this control net.

6 Move the pointer to the lower left and accept with a data point.

The edge of the surface has been stretched and is no longer linear.

Note the changes in the Top view, but you can see that this was a planar edit by looking at the Front and Right views.


B-spline Surfaces

7 Select the right front corner.

8 In the Front view move the pointer down and to the left (use AccuDraw shortcut <F> if necessary), and accept with a data point.

9 Inspect the modified surface in the Front view.

As you can see, B‐spline surfaces are flexible and you can stretch them in any direction. B‐spline surfaces can take on virtually any shape, and still you can modify them.

Another way to modify B‐spline Surfaces is with the Element Selection tool.

Exercise: Using Element Selection to modify a B‐spline Surface

1 Continuing in Surfaces.dgn, in the Modify Surface model, select Element Selection (1).

2 In the tool settings turn off Disable Handles.


B-spline Surfaces

3 Select the surface to the right and note the handles on the surface.

4 Press the Ctrl key and select the 2 handles shown.

The 2 handles change color.

5 Release the Ctrl key and select either handle.

You can now modify both symmetrically.

6 Press <T> for Top and modify the surface.


B-spline Surfaces

7 Modify the other parts of the surface.


Creation methods

As with B‐spline curves, there are 5 methods available for creating Free Form B‐spline surfaces in MicroStation:

• Define Poles

• Through Points

• Least‐Square By Tolerance

• Least‐Square By Number

• Catmull‐Rom

You can define a B‐spline surface by placing points or by applying the surface to an existing element in the model. This is determined by the Define By setting. Choose between Placement, where you place each control point or pole and Construction, which uses the vertices of a previously created construction element to define the poles. The construction element must have at least the same number of vertices as the Order, in each direction.

You can create an Open or Closed surface. A closed surface closes upon itself automatically, or you can enter an additional data point(s) to make the last data point entered the same as the first data point.

Least squares is a method of fitting data. The best fit in the least‐squares sense is a mathematical procedure for finding the best‐fitting curve to a given set of points


by minimizing (least) the sum of the squares of the offsets (the residuals) of the points from the curve. A residual is the difference between an observed value and the value given by the model. The method was first described by Carl Friedrich Gauss around 1794.

Module Review


Questions

1 What does the order of a B‐spline surface define?

2 What is a control polygon?

3 Name 2 methods you can use to define a B‐spline surface.

4 How can you modify a B‐spline surface?

Answers

1 The order of the B‐spline surface in each direction (U and V) sets the minimum number of points required to define each row or column of the control polygon.

2 Sometimes called a control net, the control polygon determines shape.

3 You can define a B‐spline surface by placing points or by applying the surface to an existing element in the model. This is determined by the Define By setting, which lets you choose between Placement and Construction.

4 You can modify a B‐spline surface by changing the control points, or poles, which make up the control polygon of the surface.


Surface Creation

Module Overview

Using the surface modeling tools in the Create Surfaces task, you can create surfaces that follow virtually any shape, no matter how complex. You will be able to create primitive surfaces, lofted and extruded surfaces, plus mesh and free‐form surfaces.



• Basic Understanding of Surfaces

Module Objectives


• Apply different surface modeling techniques

• Create a variety of 3D surfaces

Feb-09 335 Surface Creation


Surface Modeling

Surface Modeling

The Surface Modeling Tools can be found in the Surface Modeling task. The tools place surfaces using various methods.

Primitive Surfaces

Most of these tools are the same as Solid Primitives except they are created as surface models. There is a new Primitive Surface tool for creating a Pyramid, an Elliptical Cone and a Domed Surface.

A domed surface is created by placing a center point and a sphere radius.

Surface Creation 336 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Create Free Form Surfaces

After the sphere is create you can move the cursor up or down to remove the bottom or top portion of the sphere.

Create Free Form Surfaces

The Create Freeform Surfaces toolbox contains tools to place or construct a free‐form, helical surface, and to construct a surface by cross‐sections, edges, skin, or by sweeping along curves. The tools here are very powerful but rely on good graphics for sections, edges, paths, etc.

Construct Loft Surface

This tool was formerly the Construct Surface by Section tool and has been substantially modified for MicroStation V8i.

Feb-09 337 Surface CreationCopyright © 2009 Bentley Systems, Incorporated


The Loft Surface tool's Start and End Continuity settings let you control how the surface is constructed. When set to Tangent and an edge of a surface is selected, the tangency of the surface is considered. This creates a smoother transition from the original surface to the newly lofted surface.

Direction Arrows

When the loft curves are selected their start points are indicated by a direction arrow. If any curve has a reverse direction simply click on the arrow to change the curves direction. The following image demonstrates this process.

The image on left shows the start points for the loft curves. The middle image is the result of clicking on the arrow with reverse direction.

When the Force Start Point at Selection Point is enabled, you simply use the Ctrl + Data point and select the curve at your desired start point and this will force all points to have same direction.

In the image on the left, the arrows indicate all sections have the same direction.

When the Close Loft is enabled the loft curves are closed resulting in a closed surface model.



In the image on the left, the loft curves would not normally create a closed surface. On the right the results with Close Loft enabled.

Using the same section curves but Closed Loft disabled and Segmented Loft is enabled the resulting surface is made up of ruled surfaces between each set of two loft curves.

Loft Curves closed in this example, note how the surface is closed as a result of closing the loft curves.

To provide further control of a lofted surface, guide wires are now available. The wire or path curve can be an element or an edge of another surface.

Choose Edges, Faces or Surfaces for Section

Section elements that can be chosen as cross sections include the edges of solids or surfaces. Using the Loft Surface tool, you can create a surface between selected edges of 2 existing surfaces. Multiple edges are selected with Ctrl+data points. Other valid section elements are lines, line strings, arcs, ellipses, complex chains,



complex shapes, B‐spline curves, or the edges of a surface. The order in the u‐direction is 4. The order in the v‐direction is determined by the sections.

In these next exercises, you will first set the B‐Spline parameters and then use both lofting methods.

Exercise: Set the B‐spline parameters


User: untitled


2 Open Surfaces_create.dgn from the class data set.

3 Open the model 01_Construct Loft Surface.

4 Select Element > B‐spline and 3D.

Tool Setting Effect

Start Continuity Defines how the start of the generated surface merges with an existing surface. Only where start sections are part of an existing surface.• Position — The surface containing the start section is ignored.• Tangent — The start of the created surface is tangential to the surface containing the start section.

• Curvature — The start of the created surface matches the curvature of the surface containing the first section.

End Continuity Defines how the end of the generated surface merges with an existing surface. Only where end sections are part of an existing surface.• Position — The surface containing the end section is ignored.• Tangent — The end of the created surface is tangential to the surface containing the end section.

• Curvature — The end of the created surface matches the curvature of the surface containing the last section.

Force Start Point at Selection Point

• For a closed curve, the start point is at the snap point.• For an open curve, the start point is at the end nearest to the snap point.

Close Loft If on, a closed surface is constructed in which the first section curve is also used as the last section curve.

Segmented Loft If on, surfaces are created linearly between each section curve, with no

smoothing. between curves.

If off, smoothing is applied to the generated surface

Keep Profiles If on, the profile curves are retained after the surface is created.

Simplify Section Curves

If on, each input cross‐section is approximated by a smooth B‐spline curve within the specified Rebuild Tolerance value, and the surface is created from the approximation curves.

Tolerance (Rebuild Section Curves on only) Lets you change the value of the smoothing tolerance value. Smaller tolerance values cause the constructed surface to follow the construction elements more closely.



5 In the B‐spline Control Polygon section, set the following:

Surface Polygon: Invisible

Surface Display: Visible

6 In the Surface/Solid Iso lines section, set the following:

U Rules: 10

V Rules: 10

This sets the number of lines that represent the B‐spline surface in wireframe display mode.

7 Close the B‐spline and 3D dialog.

Using Loft Elements

When using loft elements, they must all go in the same direction to avoid twisting of the surface. As the elements are selected individually, an arrow displays the element’s direction and start point. If a loft element is in an opposing direction, you can reverse its direction by clicking on the arrow to Change it’s direction.

The prompts for this command include the Data‐drag for multiple profiles, this permits the selection of multiple loft curve elements only. Loft combinations that include solid and or surface edges and curve elements should use the (Ctrl + Data) selection method and select each profile member in sequential order.

Exercise: Construct a surface using Loft Surface

1 Continuing in Surfaces_create.dgn, in the model 01_Construct Loft Surface, make the Surface Modeling tasks active in the Task Navigation dialog.

2 Select Loft Surface (A + 1) and follow the prompts, with the following tool settings:

Start Continuity: Tangent

End Continuity: Tangent

Enable: Force Start Point at Selection Point



3 Select the surface edge on left side then subsequent curves and last surface edge on right side using the (Crtl + data) selection method.

Note the element direction arrow that appears at the start point of each edge and loft curve element. The arrows all begin at the top of the curves because the, Force Start Point at Selection Point, option was enabled. This also indicates that all curve directions are the same. If a curve happens to have an arrow going in the opposite direction, you can select the arrow and the direction will be reversed. Turn on level Backdrop and smooth shade with shadows to see the resulting curved display wall.

Loft by Section with Guide Wires

You can use several guide wires between two section curves to describe a surface. The two edge or section curves can be part of a surface or solid. The guide wires must be lines or curves.

Exercise: Construct a surface using Loft by Section and Guide Wires



1 Continuing in Surfaces_create.dgn, in the model 02_Loft by Section, make the Surface Modeling tasks active in the Task Navigation dialog.

2 Select Loft Surface (A + 1) and follow the prompts, with the following tool settings:

Start Continuity: Position

End Continuity: Position

Enable: Force Start Point at Selection Point

3 Select the blue‐dashed guide wire.

4 Draw a line through the red section segments.



5 Notice that the 4th section segment is in the wrong direction, click on the red arrow to make it start on the right end.

6 Data once more to see the potential surface.

7 Enter another data point to accept the surface.

8 Zoom Out and try again on the other geometry shown.


Loft Surface By Vertices


The Loft Surface By Vertices is used to construct a surface between the vertices of two profiles (or groups of profiles).

Profiles can be:

• Individual elements, or groups of elements, such as lines, line strings, arcs.

• Selected edges of one or more solids or surfaces.

After selecting the profiles, prior to accepting the displayed surface, you can manipulate the shape of the surface by:

• Clicking the direction arrows to reverse the direction of a profile.

• Dragging vertices (denoted by spherical graphics) to a new position on the profile. This manipulation is available only when the profiles have differing numbers of vertices.

Exercise: Construct a surface using Loft Surface By Vertices

1 Continue in Surfaces_create.dgn, open the model 03_Loft Surface By Vertices, make the Surface Modeling tasks active in the Task Navigation dialog.

2 Select Loft Surface by Vertices (A + 2) and follow the prompts, with the following tool settings:



3 Select the open line string and then select the arc.



4 Enter a data point to accept the surface.

Notice how it is drawing the arc to one vertex of the line string

5 Select Undo (Ctrl + Z).

6 Select Loft Surface by Vertices (A + 2).

7 Select the line string and arc again.

8 This time click on the black ball and move and snap to the other endpoint of the arc., to add an extra vertex.

9 Enter a data point to accept.

Optional Exercise: Construct a surface between Solids using Loft Surface By Vertices



1 Continue in Surfaces_create.dgn, open the model Loft Surface By Vertices Extra, make the Surface Modeling tasks active in the Task Navigation dialog.

2 Select Loft Surface by Vertices (A + 2) and follow the prompts, with the following tool settings:



3 Select the back, lower left edge of the hexagonal solid as shown.



4 Select the arc on the other solid as shown.

5 Click on the red arrow on the arc to change position of the vertex of the new surface.



6 Enter a data point to accept the new surface.

7 Rotate so that you can see the face with the edge selected, as shown:

8 Continue in the Loft Surface By Vertices command (A + 2).



9 Select the three edges shown on the hexagonal solid. Use Ctrl+data to select edge 2 and 3.

The next selection will be without the Ctrl key, telling MicroStation to select edges for the other end of the surface.

10 Select (without Ctrl) the top edge nearest to the hex solid.



11 Enter a data point on empty space to see the current surface definition.

12 Left click on the front red arrow.



13 Click and drag on the black ball to snap and copy to the other endpoint of the edge.

14 Enter a data point on empty space to see the surface.


Swept Surface along Curves


This tool extends the variety of complex 3D surfaces that you can create. With it, you can sweep 1 or 2 section profiles along 2 trace curves. Tool settings let you control how the surface is constructed.

• Swept Two Along One: Permits you to sweep two profiles along one path curve.

Swept One Along Two: Permits you to sweep one profile along two path curves.

• Scale To Second Trace: This option is enabled only if Sweep One Along Two is set to Sweep One Along Two.



• Enabled — the section profile curve is scaled as it sweeps along the 2 trace curves.

• Disabled — the second trace curve simply serves to control orientation.

• Scale Section Height: This option is enabled only if Sweep One Along Two is selected and Scale To Second Trace is enabled. If on, the section profile curve is also scaled in the height direction.

• Swept Two Along Two: Permits two profile curves to be swept along two path curves.

Exercise: Create a curved roof using Swept Surface Along Curves

1 Continuing in Surfaces_create.dgn, open the model 04_Sweep Surface Along Curves.

2 Select Sweep One Along Two (A + 3) and follow the prompts, with the following tool settings:

Method: Sweep One Along Two

Scale to Second Trace: Enabled

3 Turn on level Markers1 for all open views

4 Identify the curve at point 1, click on arrow to change first path curve start point.

5 Identify the curve point 2, click on arrow to change the start point of this path curve.

6 Select the profile curve at point 3 and accept twice to create surface.

7 Repeat this process for the other side of the roof.


Helical Surface

Note: You will have to rotate and zoom in to select remaining curves.

8 Turn off level Markers1 and turn on level, building to complete this exercise.

You can also try the extra models: Sweep Surface Extra 1, 2, and 3.

Helical Surface

The Helical Surface tool used to construct a helical‐shaped B‐spline surface by sweeping a section profile curve along a helix curve.

The Helical Surface tool has been modified such that you no longer need to use an existing helical path. The path is now created by entering the parameters of the helical geometry. The Base, Top radius, Pitch and Height.

You can use open or closed elements as the section profile curve.

In the following exercises, you will use both. In these exercises, you will find that the Front view is the easiest to use for identifying the various elements in constructing the helical surfaces.


Helical Surface

Exercise: Creating a Helical Surface

1 Continuing in Surfaces_create.dgn, open the model 05_Helical Surface. Make Geometry the active level.

2 Turn on Level, Markers1

3 Select Helical Surface (A +4).

4 Following the status bar prompt, select profile curve to create a helical surface, (point 1), press (T) to place AccuDraw in a top rotation and enter the base radius at (point 2) then enter the helical surface height at (point 3).

5 To view how this tool could be used, turn on Level garage.

6 Rotate the model to see how the pitch and height of the helical surface must be accurate for the path to end at the top of the garage surface.

The image on right is a clip volume and on left the display was set to Transparent with Shadows

Optional Exercise: Construct the bolt thread


Loft Rectangle to Circle

1 Continue in Surfaces_create.dgn, open the model Helical Surface Extra.

2 Select Helical Surface (A + 4) and follow the prompts, with the following tool settings:

Thread: Right

Base Radius: 4.0946

Top Radius: 4.0946

Pitch: 2.01

Height: 20.0138

3 In the Front view, identify the thread cross‐section.

4 Press (T) to rotate AccuDraw to the top rotation.

5 Set the base rotation radius center by moving the cursor along the ‐x‐axis and enter a data point.

6 Move cursor along the positive Z axis to set the helix pitch and height.

7 Enter a data point to accept the structure.

8 Render the view and inspect the bolt thread on the bolt.


When you need to create a transition from a rectangular section to a circle, you can use the Loft Block to Circle tool to create the required solid or surface. Settings for this tool let you define the following.



• Axis: Sets the direction of the surface relative to AccuDraw, the Screen coordinates, or the model’s (Drawing) coordinates.

• Orthogonal: If on, the axis is perpendicular to the sections.

• Top Radius: If on, sets the radius for the circular section.

• Base Length and Base Width: If on set the length and/or width of the rectangular section.

• Height: If on, sets the height of the surface.

Exercise: Creating a transition from rectangular to circular section

1 Continuing in Surface_create.dgn, open the model 06_Loft 1.

2 Select Loft Rectangle to Circle (A + 5) and follow the prompts, with the following tool settings:


Orthogonal: Enabled


3 Following the status bar prompt, snap to the vertex of the rectangular section at location 1 and accept.

4 With focus on AccuDraw, press <T> for Top rotation.

5 Snap to the opposite vertex, at location 2, and accept.

This defines the length of the rectangular section.

6 Snap to the vertex, at location 3, and accept to define the width.

7 Snap to the center of the circular section, at location 4, and accept.

8 Snap to the edge of the circular section, at location 5, and accept to define the radius of the circular section.

The surface is constructed.

9 In the Isometric view, turn off the level Location Markers.



10 Set the Isometric view’s Display Style to Smooth and use the Rotate View tool to check the construction.

Where the 2 existing elements are not symmetrical, you can disable Orthogonal to create an offset transition.

Exercise: Create an offset transition from rectangular to circular section

1 Continuing in Surface_create.dgn, open the model 07_Loft 2.

2 Select Loft Rectangle to Circle (A + 5) and follow the prompts, with the following tool settings:


Orthogonal: Disabled


3 Following the status bar prompt, snap to the vertex of the rectangular section at location 1 and accept.

4 Press <T> for Top AccuDraw rotation.

5 Snap to the opposite vertex, at location 2, and accept.

6 Snap to the vertex, at location 3, and accept to define the width.

7 Snap to the center of the circular section, at location 4, and accept.

8 Snap to the edge of the circular section, at location 5, and accept to define the radius of the circular section.


Surface by Network of Curves

The surface is constructed.

9 In the Isometric view, turn off the level Location Markers.

10 Set the Isometric view’s Display Style to Smooth and use the Rotate View tool to check the construction.

Rotated view showing the new surface

Surface by Network of Curves

Working with a network is similar to working with sections. The difference is that when you create a surface from elements arranged in a network, you must be sure that each element in the network’s u‐direction intersects each element in the network’s v‐direction.

With this tool, you first identify the sections in 1 direction (u or v) and then the sections in the other direction. Like with the previous tool, the order in which you select the network elements in each direction affects the final surface.

Each element in the network’s u‐direction must intersect each element in its v‐direction and vice‐versa.


Construct Surface by Edge Curves

Exercise: Creating a Surface by Network

1 Continuing in Surfaces_create.dgn, open the model 08_Surface by Network.

2 Make Geometry the active level.

3 Select Construct Surface by Network (A + 6).

4 Following the status bar prompt, select the 3 red section curves in order. (Do not start with the center curve). Select the first curve then use the Line‐drag for multiple curves/edges to select the remaining curves. To use this line‐drag tool hold the (ctrl+ key) and drag across the remaining curves., or you can drag a line through all of the curves.

5 Use the same process to select the green curves.

6 Enter a data point to show the proposed surface.

7 Enter a data point to create it.


With this tool you can construct a B‐spline surface that uses existing elements to define its edges. You can use lines, line strings, shapes, arcs, curves, B‐spline



curves, complex chains, and complex shapes as edges. Where the number of edges is 3 to 6 inclusive, they must meet at their endpoints.

The form of the resulting surface depends on the number of edges that are selected, as follows:

• Two edges: A ruled surface connecting either the closest or farthest ends is constructed between the edges. You can reverse closest and farthest with a Reset after selecting the edges and viewing the proposed surface.

• Three edges: You can choose between a Coons patch or an n‐sided patch in the tool settings.

• Four edges: Bi‐cubically blended Coons patch.

• Five or 6 edges: Five or 6 surfaces respectively, are joined to form 1 patch.

In the tool settings, you choose between 2 patches when 3 edges are selected.

• Method For 3 Edges: Sets the method that is used to create the surface from the 3 edges

Degenerate Coons Patch or N‐sided Patch

Using this tool, you can create a complex surface from simple edge elements.

Examples of surfaces and the edges used to create them (from 2 through 6). For 3 edges, both the Coon patch (left) and the n‐sided patch (right) are shown

With this tool you can use either of 2 methods.



First, after picking the tool you can draw a selection box around all of the edge curves or, second, you can pick the edge curves individually.

Exercise: Construct a surface from 2 edge elements

1 Continuing in Surfaces_create.dgn, open the model 09_Surface by Edge.

2 Select Construct Surface By Edge Curves (A + 7) and follow the prompts.

3 Identify the 2 red edge elements with data points.

4 With both elements highlighted, enter a data point to view the surface.

5 Accept the surface with another data point.

6 Identify the green edge and one of the red edges with data points.

Note: When you select red edge you may need to use right button to select original curve.

7 Accept the surface with another data point.

8 Change the View Display Mode to Smooth to see the result.

In some cases, surfaces created from 2 edge elements can be twisted. This is due to the method used to create the surface. Surfaces created from 2 edge elements are constructed by joining either the nearest or farthest points on each element. When a twist appears in the proposed element, a reset will reverse the way that the surface is constructed and untwist it.


Surface by Corner Points

Optional Exercise: Create a complex surface from linear elements

1 Open the model Surface by Edge Extra 1.

2 Create a surface from 4 edge elements.

The four red curves will create 1/4th of a convex surface. Select one curve then use the Ctrl key to identify each of the four red curves. Repeat this process or use the manipulate element tools to create the other surfaces. Later you will learn how to stitch these surfaces into one surface.

You can also try models: Surfaces By Edges Extra 2 and 3.

Surface by Corner Points

With this tool you can create a B‐spline surface using any 4 points on an element. A triangle can also be created by closing the fourth point on the start point.

Exercise: Create a twisted blade using Surface by Corner Points

1 Continuing in Surfaces_create.dgn, open the model 10_Surface by Corner Points.

2 Select Surface by Corner Points (A +8) and follow the prompts.


Module Review

If necessary, turn on the Markers1 level, to see the corner point sequence.

3 Place a data point in order at points (1), (2), (3) and (4), to create the surface.

4 Render the surface.

5 Undo the previously created surface and re‐create the surface using points (1), (2), (3), and (5) and compare with the previous surface.:

Rotated view showing the new surface.

Module Review


Questions

1 When using the Loft Surface tool, why is it important that all section elements go in the same direction?

2 If a profile curve is in an opposing direction, how you can reverse its direction?

3 Besides direction, what else is an important consideration when using the Loft Surface tool?

4 Name 3 types of elements you can use to define the edges of a B‐spline surface using Construct Surface by Edges.


Module Review

5 When using Construct Surface by Edges, how do you reverse the way that the surface is constructed?

6 What is an important consideration when using the Place Free‐form Surface tool?

7 When using Place Free‐form Surface, which method should you use if you want the surface to follow the curve of the defined points?

Answers

1 To prevent twisting. If one of the loft curves directions is reversed then the created surface will be twisted.

2 Select thew red arrow to modify the curve or edge direction.

3 When you select profile curves, the order in which they are selected is important. The surface will be constructed by transforming the profile curves in the order in which you select them.

4 Lines, line strings, shapes, arcs, curves, B‐spline curves, complex chains, and complex shapes.

5 Reset.

6 It is important to have geometry to snap to, or set an AccuDraw Origin from, in order to draw the surface. Creating construction geometry is advised.

7 The Through Points method.


Surface Modification and Blending

Module Overview

Tools for modifying existing surfaces are located in the Modify Surfaces task. Often the surface creation tools give you a starting surface, with the Modification tools you can trim, cut or blend surfaces together.


• Knowledge about Surfaces

Module Objectives


• Trim a surface

• Trim Surface by Curves

• Extend a surface

• Stitch and Split a Surface

• Change Surface Normals

• Blend Surfaces

Feb-09 367 Surface Modification and Blending





Questions

1 What does the order of a B‐spline surface define?


3 Name 2 methods you can use to define a B‐spline surface.

4 How can you modify a B‐spline surface?

Answers

1 The order of the B‐spline surface in each direction (U and V) sets the minimum number of points required to define each row or column of the control polygon.

2 Sometimes called a control net, the control polygon determines the shape.

3 You can define a B‐spline surface by placing points or by applying the surface to an existing element in the model. This is determined by the Define By setting, which lets you choose between Placement and Construction.

4 You can modify a B‐spline surface by changing the control points, or poles, which make up the control polygon of the surface.

Surface Modification and Blending 368 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Modify Surfaces Tools


Within the Modify Surfaces toolbox are tools that let you modify existing surfaces in a model.

Included are tools that let you trim, extend, stitch or split surfaces. You can modify B‐spline specific attributes or change the direction of surface normals.

Trim Surfaces tool

This tool lets you trim two elements to their common intersection or one element to its intersection with another element.

When selecting elements for trimming, the identified portion of the element is retained. Before accepting, you can enable Flip 1st, or Flip 2nd, for the first or second element respectively. These toggles reverse the portion that is retained and are useful if you inadvertently identify the wrong part of the element.

Feb-09 369 Surface Modification and BlendingCopyright © 2009 Bentley Systems, Incorporated


• Trim 1st Surface: If on, the first surface identified is trimmed to its intersection with the second element.

• Trim 2nd Surface: If on, the second surface identified is trimmed to its intersection with the first element.

• Flip 1st: Sets which portion of the 1st selected element is retained after trimming. Disabled — selected portion is retained. Enabled — selected portion is deleted.

• Flip 2nd: Sets which portion of the 2nd selected element is retained after trimming. Disabled — selected portion is retained. Enabled — selected portion is deleted

• Copy 1st: If on, a copy is made of the first selected element, and the original element is retained in the design

• Copy 2nd: If on, a copy is made of the second selected element, and the original element is retained in the design.

• Convert to B‐Spline Surface ‐ Converts the trimmed surface to a B‐Spline.

Exercise: Trim the 2 cylinders

1 Continuing in Surfaces_modify.dgn, in the model Trim Surface 1, delete the intersection curve created in the previous exercise.

2 Select Construct Trim (S + 1) with the following tool settings:

Trim 1st Surface: and Trim 2nd Surface: Enabled


3 Turn on the level Markers.

4 Identify the 2 cylinders at location marks 1 and 2.

These identification points also define the portions of the cylinders that should be retained.

5 Accept with a data point to view the trimmed elements.

Both elements now are trimmed back to the common intersection. When trimmed, they change from being 3D primitive cylinders to SmartSurfaces. Their display also changes to that of the default for SmartSurfaces, which is controlled by settings in the B‐spline and 3D dialog (Element > B‐spline and 3D).

6 Enable Flip 1st and Flip 2nd.

The trimmed sections are reversed, with the previously deleted portion being displayed.



7 Disable Flip 1st and Flip 2nd.

8 Enter a data point to complete the trim.

You don’t have to know exactly where to identify the elements prior to using this tool. You can adjust the settings to get the required effect after selecting the elements, but prior to accepting the construction.

Trim Surfaces by Curves

With the Trim Surfaces by Curves tool, you can:

• Punch a hole in a surface by projecting a cutting profile.

• Project a B‐spline curve onto a surface.

Tool settings let you choose how the cutting profile is projected, whether or not the surface is punched, and how it is punched. The inner edge of the newly punched out surface is called the boundary.

When using this tool, with Direction set to Orthogonal, the direction of the cutting profile’s projection is in the direction of its surface normals. Using the Change Normal Direction tool, you can check/set the direction for the cutting profile.

• Direction: Sets the direction of the projection of the cutting profile, as follows:



• Orthogonal — normal to the cutting profile.

• View — normal to the active view.

• Vector — direction is determined by 2 data points.

• Normal to Surface — normal to the plane of the surface being trimmed.

• Method: Sets the method used to trim the surface, as follows:

• Trim Surface — the region either inside or outside the projected curve is trimmed away. The identified portion of the surface is retained.

• Split Surface — the projected cutting profile divides the surface into 2 regions; 1 inside and the other outside the projected profile.

• Project Curve — projects a B‐spline curve on the surface. The surface is not altered.

• Impose Onto — the cutting profile is imposed onto the surface as a boundary (a hole is cut into the surface).

• Keep Profile: If on, the cutting profile curve is retained.

• Convert to B‐spline Surface: If on, the resulting element is a B‐spline Surface.

How to punch a hole in a surface:

1. Select the Trim Surfaces by Curves tool.

2. Identify the surface to punch, on a portion of the surface to be retained.

3. Select projection curves.

4. Accept to create the hole. Or, if Direction is set to Vector, enter the first point to define the vector direction.

5. Enter the second point to define vector direction and create hole.

Typically, you would use this tool to cut holes in pressure vessels or in surfaces that depict walls. In this example, you will cut a round hole in the upper surface of a pressure vessel. To prepare for the exercise, first check the direction of the surface normals for the cutting profile.



Exercise: Punch a hole in the surface and retain the punched region only

1 Continue in Surfaces_modify.dgn, open the model 02_Trim Surface 2

2 Select Trim Surfaces by Curves (S + 2) with the following tool settings:

Direction: Orthogonal

Method: Trim Surface

Convert to B‐spline Surface: Disabled

Keep Profile: Enabled

3 In the Top view, identify the green pressure vessel at location 1.

Note that you are using the Top view to ensure that you identify the pressure vessel within the boundary of the circle, the cutting profile.

4 Identify the circle cutting profile at location 2 (in any view).


Because you identified the pressure vessel within the region of the cutting profile, only that region remains.

6 Press Ctrl‐Z to Undo.

7 Continue with Trim Surface by Curves.

8 Select the pressure vessel anywhere else except location 1 then select the circle.

You could have identified the pressure vessel in any view, and achieved the same outcome. In View 1, however, it was most obvious visually that the ID point was within the bounds of the (orthogonal) projection of the circle.



Untrim Surface tool

Use this tool to reverse the sense of trim boundaries in a B‐spline surface or SmartSurface (convert cutouts to surfaces and vice‐versa) or remove 1 or more trim boundaries (cutouts) from a B‐spline surface or SmartSurface.

If a trim boundary is shared by 2 faces, along an edge, no change is made.

Three settings let you Reverse, Remove All, or Remove One. Reverse simply makes the punched hole a surface and the surface a hole.

How to remove trim boundary from a surface:

1. Select the Untrim Surface tool.

2. Set Trim Boundary to preferred option Remove One, Remove All or Reverse.

3. Identify the trim boundary (hole) to remove with a data point.

4. Accept with a data point to complete the removal.

3. Identify the surface with a data point.

4. Accept with a data point to complete.

In the following exercises, you will see how each of the settings works.

Exercise: Modifying a Trim Boundary of a Surface

1 Continuing in Surfaces_modify.dgn, open the model 03_Untrim Surface.

2 Select Untrim Surface (S + 3) with the following tool setting:

Trim Boundary: Reverse

3 Select the green surface with a data point.

4 Enter a second data point to accept.



This reverses the existing surface and the holes. You now have 2 surfaces where the holes used to be.

5 Undo the previous operation.

6 With the Untrim Surface tool still active, set Trim Boundary to Remove One.

7 With a data point, select the rounded trim boundary on the surface at location 1.

8 Accept with a second data point.

The selected boundary is removed.

9 Undo the last operation.

10 In the tool settings, set Trim Boundary to Remove All.

11 With a data point, select the surface.

12 Accept with a second data point.



All the trim boundaries are removed.

Stitch Surfaces

With the Stitch Surfaces tool, you can join 2 surfaces along their abutting edges creating a new surface. The surfaces must abut along an edge, or at least part of an edge.

This tool works with shapes, B‐spline surfaces, extruded surfaces, and surfaces of revolution. The Stitch Surfaces tool does not have any tool settings.

You can stitch surfaces together using selection of elements after selecting the command. You draw a box from left to right for Inside selection or right to left for Overlap selection.

In the following exercise you will stitch together 4 surfaces to create a single surface.

Exercise: Stitching surfaces together

1 Continuing in Surfaces_modify.dgn, open the model 04_Stitch Surface.

2 Select Stitch Surfaces (S + 4).



3 In any view, draw a selection box from right to left through all 4 surfaces.

The selected surfaces highlight.

The selected surfaces are stitched together forming a single surface. Observe that the display of the surface is different. It has become a single SmartSurface. The color of the resulting surface is red, as this was the first element placed in the design.

Using the Stitch Surface tool is a good way to create surfaces from existing elements. From simple surfaces you can create complex SmartSurfaces and then modify these using other SmartSolid and SmartSurface tools.

You can now do further editing on the whole surface.



Offset Surface

The Offset Surface command is used to construct a B‐spline surface by offsetting an extruded surface, surface of revolution or a B‐spline surface.

The Tool Settings have the following effect:

• Distance ‐ If on, sets the offset distance in the surface normal direction.

• Keep ‐ Original If on, the original element is retained.

• Face Only ‐ If on, lets you select an individual face of a surface to offset.

Change Normal Direction

Surface Normals are indicators that are generated every time you create a surface. They are invisible during the creation process and after the surface is created. The only time that you see them is when you use certain surface modification tools and the Change Normal Direction tool.

A normal to a surface is an imaginary line that is perpendicular to the surface at a given point.



It determines the side of the surface that is on the outside. You have the possibility of 2 such lines on any given point on the surface. These lines are 180° apart, on either side of the surface. The Change Normal Direction tool flips the normal 180°, thus changing the outside of the surface to the inside and vice‐versa.

Surface Normals indicate the direction of the surface for rendering and some surface modification tools. One of these tools, Trim Surfaces by Curves, uses an element as a cutting profile. The direction of the surface normals of this element determines in which direction the cutting profile is projected.

Exercise: Checking/changing direction of Surface Normals

1 Continuing in Surfaces_modify.dgn, open the model 05_Normals and Project.

2 Select Change Normal Direction (S + 6).

3 Identify the pressure vessel with a data point.

Surface normal arrows display. They are pointing outwards from the center of the pressure vessel.

4 Select the Arrow to change the surface normal direction and accept with data point.

5 Identify the circle with a data point.

Surface normal arrows display. They are pointing downward from the circle.

6 Select the Arrow to change the surface normal direction and accept with data point.

7 Identify the pressure vessel with a data point.



Surface normal arrows display. They are pointing outwards from the center of the pressure vessel because when you checked them previously and Reset, their direction was not changed.

8 Reset to leave them as they are.

9 Identify the circle with a data point.

Surface normal arrows display. They are pointing upward from the circle, whereas previously they pointed downward. They changed direction because you clicked on the arrow, entered a data point to accept the change.

10 Reset to leave them pointing in the displayed direction.

Typically, this tool is used in conjunction with other tools where the surface normals affect the operation of the tool.

Extend Surface

With the Extend Surface tool, you can extend an edge of a surface, similar to extending a line with the Extend tool. You can use this tool to extend different types of surfaces, such as a cone, extruded surface, surface of revolution, or B‐spline surface along 1 of its edges. Settings for this tool determine how the surface is extended.

• Extend Mode: Sets how the surface is extended:

• Tangential — extension is tangent continuous at the joint of extension.

• By Angle — extension is at an angle as specified in the Angle field.



• Distance: If on, sets the distance of the extension.

• Angle: (Extend Mode set to By Angle only) Sets the angle at which the extension is made. An angle of 0° creates a tangential extension.

• Make Copy: If on, a copy is made and the original surface is retained in the design file.

Exercise: Extend edges of a B‐spline surface

1 Continuing in Surfaces_modify.dgn, open the model 06_Extend Surface 1.

2 Select Extend Surface (S + 7) with the following tool setting:


3 In the Top or Right view, identify the surface with a data point at the edge near location 1.

The proposed extension displays.

4 Enter a data point to accept the extension.

5 In the Top or Right view, identify the surface with a data point at the front edge.

6 Enter a data point to accept the extension.

You can extend the 2 remaining edges.


Fillet Surfaces Tools

7 With the Extend Surface tool still active, use the Front view to identify the remaining edges.

Note: The exercises suggest views that help you identify the correct edge clearly. In fact, you could work in any view.

Merge Surface to Edge

The Merge Surface to Edge is used to merge the selected edge of a B‐spline surface to the edge of a second surface. Typically, you can use this tool to heal small gaps between two surfaces, without creating a third intermediate surface. You are not creating a new surface, you are extending an existing surface.

The Tool Settings have the following effect:

• Continuity Defines how the first surface is merged to the second surface.

• Position — The surface containing the second edge is ignored. Only the selected edge is considered.

• Tangent — Lets you merge the first surface so that it is tangential to the second surface.

• Curvature — Lets you merge the first surface such that it matches the curvature the second surface.

• Factor (Continuity set to Tangent or Curvature only) Lets you control the degree to which tangency/curvature setting affects the shape of the merged surface.


The SmartSolids Fillet Edges and Chamfer Edges tools let you round or chamfer edges on solids, along continuous surfaces. SmartSurface tools let you join separate surfaces with a fillet or blend.



Find the Fillet Surfaces tools at the end of the Modify Surfaces task.

Fillet Surfaces tool

Use the Fillet Surfaces tool to join 2 surfaces with a curved surface. The 2 surfaces that you are joining do not have to touch, but they must be within the range of the fillet radius.

Tool settings let you choose which elements are trimmed during construction of the fillet.

• Truncate: Defines which surface(s) are to be truncated (trimmed back):

• Both — both surfaces are trimmed.

• First — the first surface selected is trimmed.

• None — neither surface is trimmed

• Face Only: Allows the selection of one face at a time if multiple faces are present in either surface. For example, if a fillet is created between a slab and a surface and this check box is selected, the faces of the slab could be selected. This check box is available only if Truncate is set to None.

• Radius: Sets the radius of the fillet.

Exercise: Create a fillet between surfaces (both truncated)

1 Continuing in Surfaces_modify.dgn, open the model 07_Fillets

You will construct fillets between various parts of the lamp in the model.

2 Select Fillet Surfaces (S + 9) with the following tool settings:

Truncate: Both

Radius: 15

3 In View 3, select the top of the base at location 1 with a data point.

4 Select the pole at location 2.

5 Enter a data point to view the proposed fillet.

The proposed fillet displays.



6 Enter a data point to accept the construction of the fillet.

With the fillet constructed, the pole, fillet and top surface of the base now are all part of a single SmartSurface. Continue by placing a fillet on the outside edge of the base.

7 Select the vertical edge of the base at location 1 with a data point.

8 Select the edge of the top surface of the base, at location 1.

The pole, fillet and top surface of the base all highlight.


10 Accept the construction of the fillet with another data point.

11 In View 3, turn off the level Markers.

12 Set View 3’s View Display Mode to Smooth and inspect the results of the fillets.

If there is a choice as to the side on which the fillet is placed, the location is determined by the direction of the surface normals.



Exercise: Create another fillet

1 Continue in Surfaces_modify.dgn, in the model 07_Fillets, select Fillet Surfaces (S + 9) with the following tool settings:

Truncate: None

Radius: 30

2 In View 1, select the circular section at location 3 with a data point.



5 Accept with a data point to complete the construction.

The pointer location did not control the side of the circular section on which the fillet was placed. It was placed on the side of the circle from which the surface normals point. For the next fillet, you will change the direction of the surface normals to place the fillet on the lower side of the circular section.

Exercise: Determining the direction of a fillet

1 Continue in Surfaces_modify.dgn, in the model 07_Fillets, select Change Normal Direction (S + 6).

2 Select the circular section at location 5 with a data point.

Surface normals display. They are pointing upward. This would produce a fillet on the upper face of the circle as it did for the circular section below.

3 Enter a data point to reverse the direction of the surface normals.

With the surface normals pointing in the correct direction, you can continue with the construction of the fillet.

4 Select Fillet Surfaces (S + 9) with the following tool settings:



Truncate: None

Radius: 30

5 In View 1, select the circular section at location 5 with a data point.



This time the fillet is placed on the lower face of the circular section.

8 Accept with another data point to complete the fillet.

You can see that the fillet has been placed on the lower side of the circular section. This is most evident in the Front view.

Hint: If you want to truncate only 1 of the surfaces that you are filleting note that, with Truncate set to Single, the first surface selected is truncated.

Fillet Surfaces along Curves

This tool is used to construct a blending B‐spline surface between 2 surfaces along their rail curves. The curve must be an element lying on the surface. The curves can be elements such as lines, arcs, line strings, ellipses, complex shapes, complex chains, or B‐spline curves. Surfaces that may be blended in this way include extruded surfaces, surfaces of revolution, cones, or B‐spline surfaces. Tool settings let you choose a Chamfer or Round blend.

Typically, you could use any of the following tools to create a curve on a surface:

• Extract Face or Edge Geometry in the 3D Utility toolbox.



• Project Trim in the Modify Surfaces toolbox.

• Extract Iso‐parametric Lines in the Create Curves toolbox.

If a surface is flat you could simply draw the curves on the surface. In this example, the Project Trim tool was used to produce the green dashed curve on the green surface, while the Extract Iso‐parametric Lines tool created the yellow dashed curve on the hexagonal solid. As with all tools, follow the status bar prompts as you proceed.

Tool settings are:

• Method ‐ Sets the type of fillet.

• Round — Smooth circular blend also know as a rolling ball blend.

• Chamfer — Chamfer blend.

• Fillet Surface Type ‐ Sets the type of trim for the generated surface.

• Trimmed — Trims the generated surface to the bounds of the curves.

• No Trim — Does not do any trimming.

• Long Trim — Trims to the longest of the two curves.

• Short Trim — Trims to the shortest of the two curves.

• Truncate Originals ‐ If on creates a single surface.

• Keep Original ‐ If on retains the originals if Truncate Originals is on.

Exercise: Create a chamfer blend between curves

1 Continuing in Surfaces_modify.dgn, open the model 08_Fillets.

2 Select Fillet Surfaces along Curves (S + 0) with the following tool setting:

Blend Type: Chamfer

Fillet Surface Type: Trimmed

3 Select the green B‐spline surface at location 1 with a data point.

4 Select the red dashed curve at location 2.

5 Select the yellow hexagonal solid at location 3.

6 Identify the face in front.

7 Select the yellow dashed rail curve at location 4.

8 Enter a data point to view the blend.



9 Accept the blend with a data point.

The blend is constructed. In the Isometric view, you can see that it has a straight (chamfer) slope.

Exercise: Create a round blend between rail curves


2 Select Fillet Surfaces along Curves (S + 0) with the following tool setting:

Blend Type: Round

3 Select the magenta B‐spline surface at location 1 with a data point

4 Select the magenta dashed rail curve at location 2.

5 Select the red hexagonal solid at location 3.

6 Select the front face.

7 Select the red dashed rail curve at location 4.

8 Enter a data point to view the blend.



9 Accept the blend with a data point.

The blend is constructed. In the Isometric view, you can see that it has a curved (round) slope.

Blend Surfaces

You can use this tool to construct a blend between 2 elements (extruded surfaces, revolved surfaces, cones, or B‐spline surfaces) with a specific order of continuity. The resulting B‐spline surface consists of the trimmed original elements and a transition that connects them.

Setting the Continuity specifies how the blend between the surfaces is formed. The direction of the first and last tangents of the blend is the direction of the tangents of the original elements at their trimmed edges. You can adjust the relative magnitudes of these tangents to achieve the desired blend.

With this tool, you can change the settings to interactively view the proposed blend prior to accepting it with a data point.

• Continuity: Sets the order of continuity of the blend surface:

Position — produces a straight surface between the blend points.

Tangent — has 2 control rows and columns in the u and v directions. This setting is appropriate for most cases.

Curvature — has the u and v values set to 4.

• Factor 1: Sets the magnitude of the initial tangent.

• Factor 2: Sets the magnitude of the final tangent.



When selecting surfaces, the finished blend assumes the color of the first selected surface.

Exercise: Create a blend between 2 extruded surfaces


2 Select Blend Surfaces (S + Q) with the following tool settings:

Start Continuity: Curvature

End Continuity: Curvature

Start Continuity Reverse: Enabled

End Continuity Reverse: Enabled

Start Factor: 15

End Factor: 5

3 In the Isometric view, select the green surface at location 1.

This determines the edge where the blend will start.

4 Select the surface at location 2 to define the second edge to be blended.


If you do not see a surface click on the red arrows to change the start point. The proposed surface displays.

6 In the tool settings, use the slide controls to change the values for Factor 1 and Factor 2 to 50.


Module Review

It makes no difference to the proposed surface. Because Continuity is set to Position, the blend is restricted to the 2 selected positions on the surfaces.

7 Return the Factor 1 and Factor 2 values to 0.


Continuity: Tangent.

9 Use the slide controls to change the values for Factor 1 and Factor 2.

Changing these values changes the shape of the blend.

As Factor 1 and Factor 2 settings are changed the blend changes accordingly

10 Change the Continuity setting to Curvature and repeat step 10.

11 When you are happy with the shape of the blend, enter a data point to complete it.

Module Review


Questions

1 When using the Construct Trim tool, which portion of the element is retained?

2 True or False: When using the Construct Trim tool, you can adjust the settings to get the required effect after selecting the elements.


Module Review

3 What are Surface Normals?

4 What is an important consideration when using the Construct Stitch tool?

5 When using the Construct Stitch tool, what is the resulting element color if you select the surfaces first, then the tool?

6 When working with B‐spline surfaces, their display is represented with what?

Answers

1 When using the Construct Trim tool, the identified portion of the element is retained.

2 True. Adjust the settings to get the required effect after selecting the elements, but prior to accepting the construction.

3 Indicators that are generated every time you create a surface. They are invisible during the creation process and after the surface is created. The only time that you see them is when you use certain surface modification tools and the Change Normal Direction tool.

4 The surfaces must abut along an edge, or at least part of an edge.

5 The color of the resulting surface is that of the surface which was placed in the file first.

6 Their display is represented with rule lines. The more rule lines that are used to display the surface, the easier it is to visualize in wireframe mode.


Modify B‐spline Surfaces

Module Overview

Tools for modifying B‐spline surfaces are located in the Modify B‐spline Surfaces task. These tools differ from the last set, as they apply to B‐Spline surfaces only.


• Knowledge about B‐spline Surfaces

Module Objectives


• Edit Surface Control Points

• Change the Surface Order

• Change the Surface Closure

• Rebuild Surfaces

• Combine Surfaces

• Split Surfaces

• Apply the Surface Handlebar

• Twist Surfaces

Feb-09 393 Surface Modification and Blending





Questions

1 B‐Spline surfaces use the same methods as B‐Spline _________.

2 True or False: Surfaces can be created by extracting them from Solids.

3 With Surface Modeling it is important to start with good ____ profiles.

Answers

1 Curves

2 True

3 2D

Modify B‐Spline Surfaces

There are many ways to modify a B‐Spline surface. FOr example, one of the handiest and easiest ways is to use the Element Select tool (1) and select the surface. You can then use Ctrl+data point to select individual handles or a group of handles to edit.

Specific tools have been design to control other modifications to B‐Spline surfaces.


Modify B-Spline Surfaces

Edit Surface Control Points

When you create a B‐spline surface, various settings that determine its construction and appearance are controlled by options in the B‐spline and 3D dialog.

They define the default settings that apply to surfaces as you place them in your models. Once a B‐spline surface has been placed, you can change its settings using the Edit Surface Control Points Settings tool.

When working with B‐spline surfaces, their display is represented with rule lines. The more rule lines that are used to display the surface, the easier it is to visualize in wireframe mode. But they can cause unnecessary screen clutter, and updates can be affected when the design is complex.

Exercise: Add rule lines to a B‐spline surface

1 Open Surfaces_modify.dgn, and open the model 11_ Surface Settings 1.

2 Set the Isometric view’s View Display Mode to Smooth.



The model, which looked like 4 simple edge elements in wireframe display, is really a B‐spline surface.

This B‐spline surface was created with U Rules and V Rules both set to a value of 2. Thus, only 2 lines display in each direction to represent the surface in wireframe display mode. To help you visualize the B‐spline surface in wireframe display, you can increase the number of rule lines.

3 Set the Isometric view’s View Display Mode to Wireframe.

4 Select the Edit Surface Control Points tool (D + 1) with the following tool settings:

Edit Rule Line: Enabled and both U and V set to 5


6 Accept with a data point to make the change.

The surface is more easily seen in wireframe display. There are 5 rule lines in each direction, as specified. This is an improvement, but you can see better if you increase the number of V rules.



7 Unlock the Number of Rule Lines by selecting the lock icon


Edit Rule Line: Enabled with U set to 5 and V set to 15



With the new value, the surface is easier to see in wireframe mode.

You can change other settings for B‐spline surfaces as well as the display parameters. You can turn on the display of the control polygon and change the Order of the surface.

Exercise: Change control polygon and surface settings for a B‐spline surface

1 Continuing in Surfaces_modify.dgn, open the model 12_Surface Settings 2.

2 Select Edit Surface Control Points, with the following tool settings:

Show Control Polygon: Enabled






With the hide surface option enabled, you can make the surface invisible.


Hide Surface: Enabled

6 Identify the surface and accept with a data point.

The surface disappears, leaving the control polygon.

7 Change the Surface tool setting back to visible and repeat the previous step to turn the surface display on again.

Change Surface Order

You can change the order of the B‐spline surface with or without preserving its current shape. The higher the order the smoother (flatter) the surface.



Exercise: Change the order of the B‐spline surface

1 Continuing in Surfaces_modify.dgn, in the model 12_Surface Settings 2, set the following Change Surface Order tool settings:

Order: Enabled for both the U and V directions and values set to 5


When you enable Order, you have the option of whether or not to preserve the shape of the original B‐spline surface. First you will try the tool without preserving the shape.

2 Identify the surface with a data point.


Note the change in the shape of the surface. Note also, that it still is contained within the control polygon, which remains unchanged.

4 Undo the previous operation.


Preserve Shape: Enabled

6 Identify the surface and accept with a data point.

7 This time, the surface retains its original shape, but the control polygon has changed and now has many more points.



Change Surface Closure

Used to change the closure settings in the U and/or V direction for a B‐spline surface. You can change closure of a surface in the U or V direction.

Rebuild Surface

You can rebuild a surface with different parameters. The following are available:

• Reduce Data — Used to remove unnecessary control points from a surface with tolerance.

• Rebuild with Tolerance — Used to remove cusp points on a surface by sampling a set of points from the surface and recreating it.

• Rebuild with Num Poles — Similar to Rebuild with Tolerance, but with a fixed number of poles as input.

• Swap UV — Swaps the U and V directions, so that U becomes V and vice versa.

• Reverse U — Reverses the U direction.

• Reverse V — Reverses the V direction.

• Make Uniform Knots — Where a surface has all the knots concentrated in a certain region, such as to one side of the surface, it may be that the 0.5 knot is not near the center of the surface. This option attempts to rebuild the surface such that the 0.5 knot corresponds, as near as possible, to the center of the surface.



Combine Surfaces

This technique is used to combine B‐spline surfaces that share a common edge. The result remains a B‐spline surface and takes on the color of the first selected surface. Simply select two or more surfaces with common edges and they will combine into a single B‐spline surface.

Split Surface

Just as the Stitch Surface tool lets you join surfaces into a single entity, the Split Surface tool lets you take 1 surface and split it into 2 surfaces. You can use it to break up a primitive, like a slab or a cylinder surface. When you split a surface, it automatically becomes a B‐spline surface regardless of what it was previously. In effect, this tool is similar to the Delete Part of Element tool. Delete Part of Element works with linear elements, but the Split Surface tool works with surfaces.

The tool settings defines how the surface will be split.

• By Point — Selecting a point to split or split and drag to make a gap.

• By Numbers — Split into numbers of U and V line sections.

• At Crease Iso Curves — Makes a split at an iso curve.

• Into Bezier — Splits the surface into a Bezier surface

Exercise: Splitting a surface

1 Continuing in Surfaces_modify.dgn, open the model 13_Split Surface.

2 Select the Split Surface tool (A + 6), with the following tool settings:

Method: By Point



3 In the Isometric view, snap to the red surface at location 1 and accept with a data point.

4 Snap to location 2 and accept with a data point.

As you move the pointer, you are dynamically viewing the deletion of part of the surface, horizontally.

5 Reset to change the direction of the deletion.

Now, as you move the pointer, you are viewing the deletion of part of the surface, vertically.

6 Move the pointer to location 2, and accept with a data point, to complete the deletion.

Because the original surface that you modified was a B‐spline surface, there was no significant change in the way that the modified surface displayed. When you split a primitive, the modified surface becomes a B‐spline surface and the display changes according to the B‐spline display settings.



Exercise: Splitting the cylinder

1 Continuing in Surfaces_modify.dgn, in the model Split Surface, select 13_Split Surface (A + 6).

2 In the Isometric view, snap to the green cylinder at location 3 and accept with a data point.

3 Select the cylinder to set the direction for the split.

As you move the pointer, you are dynamically viewing the deletion of part of the cylinder, vertically.

4 Reset to change the direction of the deletion.

Now, as you move the pointer, you are viewing the deletion of part of the cylinder horizontally.

5 Snap to the cylinder at location 4 and accept with a data point to complete the deletion.

The cylinder has been split into 2 sections.

Exercise: Split a complex B‐spline surface

1 Continuing in Surfaces_modify.dgn, open the model Split Extra.

2 Select Split Surface (A + 6).

3 Select one edge of the yellow surface and accept with a data point.



In the Top view, note that the surface is partially deleted in the x direction as you move the pointer.

4 Reset to change the direction of the partial deletion to the y direction.

5 Enter a data point to complete the partial deletion.

Surface Handlebar

The Surface Handlebar tool is used to modify the shape of a surface, by controlling the tangency in two directions at one point on the surface. You should use this tool for small, fine adjustments needed for part of a surface. Perhaps to ensure clearance or ensure that they touch.

How to modify a surface using handles:

1. Select the Surface Handlebar tool.

2. Identify the surface.

3. Select the position for the base point of the handlebars. Handlebars appear at the selected location on the surface.

4. Click and drag the handles to modify the surface.



Twist Surface

The Twist Surface tool is used to create a twisted B‐Spline surface or mesh about a defined axis. By increasing the number of control points you will create a smoother surface.

The tool settings are:

• Fixed Twist Angle ‐ If on, sets the angle that the surface is twisted about the length of defined axis.

• Infinite ‐ If on the surface will be twisted beyond the length of the axis or below the starting point of the defined axis.

How to create a Twisted Surface:

1. To create a twisted surface you select the surface

2. Then define an axis of rotation

3. Define a reference point to indicate the start and end of the rotation.

Original surface on left, middle start and end of rotation and right side resulting twisted surface.


Module Review

Module Review


Questions

1 The Edit Surface Control Points commands lets you change settings found in the menu: Element > _________

2 True or False: When using the Change Surface Order tool, you can adjust the settings to see the required effect after selecting the elements.

3 What are Rule Lines?

4 What is the way to change the direction of a split in the Split Surface command?

Answers

1 3D and B‐Spline

2 True. Adjust the settings to get the required effect after selecting the elements, but prior to accepting the construction.

3 Rule Lines help to visualize a surface. The more rule lines that are used to display the surface, the easier it is to visualize in wireframe mode.

4 Right‐click.


Surface Utilities

Module Overview

Tools for modifying surfaces are located in the Modify Surfaces task.


• Knowledge about creating Surfaces

• Knowledge about editing and modifying Surfaces

Module Objectives


• Convert standard surfaces to SmartSurfaces and B‐spline surfaces.

• Extract points or faces from a Surface.

• Extract iso curves from a surface.

• Create a planar slice through a Surface or Solid.

• Compute the intersections between surfaces, Solids and elements.

• Unroll a developable surface.

• Create a surface from an image.

• Show surface curvature.

• Match surface settings.

Feb-09 407 Surface Utilities





Questions

1 What tool is usually the quickest and easiest way to edit a surface?

2 True or False: Changing Surface Order can change the shape of a surface.

3 True or False: Twist Surface allows you twist along the length of an axis or an infinite length along that axis.

Answers

1 Element Selection. Edit handles to edit the surface.

2 True.

3 True. Infinite is a tool setting option.

Surface Utilities 408 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Surface Utilities

Surface Utilities

Within the Surfaces Utilities toolbox are tools to extract curves from B‐spline surfaces.

Included are tools that let you convert a solid to a surface, extract points, iso lines, create a planar slice, computer intersections, unroll a developable surface, create surface by image, show surface curvature and match surface settings.

Convert To Surface

The Convert to Surface tool converts a solid to a surface or standard surfaces to B‐spline surfaces.

Feb-09 409 Surface UtilitiesCopyright © 2009 Bentley Systems, Incorporated

Surface Utilities

In this image you see a Solid Primitive Ellipsoid. By selecting the Convert To

Surface tool with the Convert to, set to B‐spline Surface, the solid is converted.

Exercise: Convert a Solid to a Surface and modify surface

1 Open Surface_utilities.dgn, and open the model 01_convert to surface.

2 Use the Element Information tool to verify that the Ellipsoid is a SmartSolid.

3 Select Convert To Surface (F + 1) with the following tool settings:

Convert To: Set to B‐spline Surface


4 Pick the Ellipsoid and accept with a data point.

5 Use the Element Information tool to verify that the Ellipsoid is now a B‐spline surface.

Note: The conversion to B‐spline surface has split the previous SmartSolid into two surfaces. To combine these two B‐spline surfaces into one B‐spline surface use the Combine Surfaces tool.


Surface Utilities

Extract Points from Surface/Face

The Extract Points from Surface/Face tool is used to evaluate attributes of a B‐spline surface or a SmartSolid face. The attributes that can be created are points, tangents and normal directions. The attributes can be extracted over the complete surface, at a specific point, by a UV parameter or by a distance along a curve.

For example here are two surfaces that need to be offset by .1 units.

By rotating the surfaces to a side view you can see that the top surface is not a constant offset of the bottom surface.


Surface Utilities

To evaluate the offset of the bottom surface you extract the Normals by Point Array with a Normal Plot Scale set to the optimum offset value. In this case .1 units. Then zoom into the normals to see how far the offset has deviated from the .1 unit offset.

Measure the distance and see that it is .05 units greater than the desired .1 offset. Then by using the Element Selection tool you can move the top surface pole to the .1 offset normal.

Other attributes that can be extracted are tangent lines and points.


Surface Utilities

Extract Iso‐Curves

The Extract Iso‐Curves tool is used to extract the iso‐curves from a B‐spline surface or a Solid face. You can extract a single curve or multiple curves evenly spaced.

Iso‐curves have a parametric value from 0 to 1 in the U and V direction of a surface or solid face. When a single curve is specified, you can set the position graphically or use the Iso Value setting to position it on the surface.

• Extract: Sets the objective of the tool:

Single Curve — Extract a curve that has a constant parametric u‐value (iso‐u curve) or constant parametric v‐value (iso‐v curve). The u‐value or v‐value is the specified Iso Value. The u‐direction is the direction in which the data points that defined each row were entered. The v‐direction is the direction in which the columns were defined.

Multiple Curves — Extract a set of curves that are spaced evenly on the surface in both directions.

• Iso Value: (Enabled only if Extract is set to Single Curve) If on, sets the iso value of the extracted curve.

• Numbers U/V: (Enabled only if Extract is set to Multiple Curves) Sets the number of curves extracted from both parametric u‐ and v‐directions.

• Ignore Trim Region(s): (Enabled only if Extract is set to Multiple Curves) If off, the curves are trimmed by the B‐spline trim curves, if any.

When using this tool, the generated surface rule lines take the active element attribute settings.


Surface Utilities

Note: If you reset before accepting the iso‐curve it will switch to the opposite U or V direction.You can also use the sliding bar to set an iso value.

In the following example a single iso‐curve is extracted from a surface and a solid with an iso value of .5.

Exercise: Extract multiple curves from a primitive solid

1 Open Surface_utilities.dgn, and open the model 02_extract iso‐curves.

2 Make a copy of the Ellipsoid.

3 Select Extract Iso Curves (F + 3) with the following tool settings:

Extract: Multiple Curves

U Numbers: 10

V Numbers: 10

4 Select the ellipsoid and accept with a data point.

5 Delete the SmartSolid that you used to extract the iso‐curves


Surface Utilities

6 Render the image to see the B‐spline curves extracted from the solid model.

Optional Exercise: Extracting single surface rule lines in either the u or v direction

1 Continuing in Surfaces_utilities.dgn, open the model Iso Extra 1.

2 Select Extract Iso‐parametric Line (F + 3) with the following tool settings:

Extract: Single Curve

Iso Value: Disabled

3 In the Top view, select the surface with a data point.

A horizontal rule line appears on the surface.

4 As you move the screen pointer, the surface rule line moves over the surface. As it moves, check all views and see how it changes shape to match the surface.

5 Reset to change the direction of the surface rule line.

The direction of the rule line changes to vertical (in the Top view). Again, as you move the screen pointer, the surface rule line moves over the surface, changing shape to match the surface.


Surface Utilities

6 Enter a data point to place the surface rule line approximately in the center of the surface.

If you enable the Iso Value setting, you can position the extracted surface rule line exactly on the surface. Values can be from 0 through 1, where, for example:

• 0 places the rule line on 1 edge.

• 1 places the rule line at the opposite edge.

• 0.25 and 0.5 places the rule line quarter or mid‐way between the edges, respectively.

If you set Extract to Multiple Curves, you can place a network of surface rule lines on the surface.

Exercise: Extract Multiple Curves from a surface

1 Continuing in Surfaces_utilities.dgn, open the model Iso Extra 2.

2 Select Extract Iso‐parametric Line (F + 3) with the following tool settings:

Extract: Multiple Curves

Numbers: 10 (for both U and V fields)

Ignore Trim Regions: Disabled

3 In any view, identify the surface with a data point.

4 Accept with another data point, to complete the construction.

5 Each of the iso lines created is a B‐spline curve that can be manipulated, or used, separately from the originating surface.


Surface Utilities

Planar Slice

The Planar Slice tool is used to generate a planar section through design geometry. The cutting plane can be an existing planar element or a plane defined by three points or a plane perpendicular to a view and defined by two points. If Assemble Segments is enabled then the individual lines of a planar section are assembled into a line string.

In this example the ellipsoid has copies of an existing Block element, and with the Slice by Element selected in the tool settings, the resulting planar slices are created.

Exercise: Planar Slice through a 3D model.

1 Continue in Surface_utilities.dgn, and open the model 03_planar slice.

2 Select Planar Slice tool (F + 4) with the following tool settings:

Slice by View: Enabled

Assemble Segments: Enabled


Surface Utilities

3 Create the first point of the slice, 2.9983 units in the Y direction from the base of the domed structure.

4 Enter the last point of the planar slice, reset to preview and data point to accept planar slice. Change view to right‐isometric.

5 This slice can then be used to create an interior floor of the domed structure by dropping the planar slice using the Drop Element tool with the following tool settings:

Complex: Enabled



Surface Utilities

6 Delete the outer wall planar slice and keep the inner slice as the interior floor of the domed structure.

Compute Intersections

The Compute Intersections tool is used to calculate the intersection point between elements. For example, the intersection of a line or curve with a surface, mesh or solid model.


Surface Utilities

In this example the center lines of pipes go through a solid structure and you need to find the intersections of these line elements with the structure.

Select the Compute Intersections tool (F + 5). You are then prompted to select the first group and in this example the solid structure is selected. You are then prompted to select the second group. The second group contains the center lines and they are selected by dragging a box from right to left which will select all the center lines. Accept with a data point to compute the intersection points.

Unroll Developable Surface

This tool is used to flatten a surface. A developable surface is typically a ruled surface that can be flattened to a plane without distortion.


Surface Utilities

Here are surfaces that were created from projections onto an ellipsoid.The surface to be flattened is displayed with an increased number of U and V lines.

Select the Unroll Developable Surface tool (F + 6) and click on the surface, a point that you want to start the unrolling and another point to determine the axis for the unrolling. The flattened surface has been dimensioned to see the changes after flattening.

Surface By Image

The Surface by Image tool is used to create an approximate B‐spline surface from a raster image. Probably, one the most fun 3D surfacing tools!


Surface Utilities

Exercise: Create a B‐spline surface from an aerial photograph

1 Open Surface_utilities.dgn, and open the model 04_Surface by Image.

2 Set View to Top view.

3 Select Surface by Image tool (F + 7) with the following tool settings:

Image File: image_surfbyimage.tif

Proportional to Image: Disabled

Height: 10

U Sample Points: 20

V Sample Points: 20

4 Click in the lower left corner of the view, in response to the prompt “Enter First Point”.

5 Click in the upper right corner of view in response to the prompt “Enter Second Corner Point to define Window Area”.

The height is a scale factor which can be used to create a desired elevation for visibility. This surface example also has the image used to create the surface,

mapped to the surface via MicroStation visualization tools. The image is mapped to the color white in View Attributes.

You can also increase sampling points which will increase surface details but will slow down the rendering time. I recommend not increasing the U V Sample Points


Surface Utilities

higher than 40 for this example. In the following image the U V Sample Points have been set to 40.

Note: The color of the original image determines if the surface is convex or concave. Black is the maximum concave point and white is the maximum height for convex surfaces.

Show Surface Curvature

This tool is used to show curvature by placing a range of colors on a surface and as the curvature increases a color reflects this change.

For example the following is a flat B‐spline surface and by selecting the Show Surface Curvature tool a solid color is displayed on the surface indicating no perceptible change in curvature.


Surface Utilities

By modifying the poles on the surface to create curvature the colors reflect this increase in curvature.

Exercise: Evaluate curvature on a complex surface

1 Open Surface_utilities.dgn, and open the model 05_Show Surface Curvature.

2 Select Show Surface Curvature tool (F + 8).

3 Click on the complex surface in View 1.

4 The resulting curvature changes are displayed by changing colors.


Surface Utilities

5 Right click and a colored wireframe of curvature is displayed. Right click one more time and you will return to wireframe.

Match Surface Settings

The Match Surface Settings tool (F + 9) is used to change the active B‐spline settings. By selecting an existing surface the settings for that surface are matched in the Active B‐spline settings. In the following example the Active B‐spline settings are set to 10 U and 10 V lines. By selecting the existing surface the settings for the surface are matched and change the Active B‐spline settings in the tool settings.


Module Review


Questions

1 You can convert a B‐Spline surface to a Mesh or a ______?

2 True or False: The Iso curve has equal value for U or V throughout the surface.

3 You can create a Planar Slice: By View, By Three Points or By _______

4 True or False: Surface by Image supports most major image formats.

Answers

1 Solid.

2 True.

3 Element.

4 True.


Meshes

Module Overview

Meshes are polygonal objects arranged in 3D to make a surface. This module covers some of the basic procedures used to create surface models using MicroStation Meshes.



• Knowledge of 3D Surfaces

Module Objectives


• Create Meshes

• Modify Meshes

Feb-09 427 Meshes


Mesh Surfaces

Mesh Surfaces

The Mesh tools allow you to create polygonal mesh surfaces. These surfaces are approximations of a true surface and are made up of polygons (usually triangles and quadrilaterals). As you zoom in on a Mesh surface you start to se the faces/facets of the surface.

With a mesh the object is broken down into triangles (or other polygons) that can be used to approximate the volume of surface of an object that would normally take hours to get an exact volume of surface area.

If you are interested in the volume of something rectangular then there is no advantage to converting this a mesh, since all you are doing is totaling the six sides of the volume. The Mesh model simply breaks up complex geometry into several simple chunks of geometry that can be calculated then totaled to give an approximation.

Mesh modeling is very popular in other 3D applications most notably entertainment, but has application in building, plant as well as civil and geospatial disciplines.

The mesh tools can be accessed from the Surface Modeling task.

The Mesh tools

The first tool lets you create meshes. The second tool provides Boolean operations and the last tool is the Modify Mesh tool.

Meshes 428 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Creating a Mesh

Creating a Mesh

Meshes can be created in 5 ways:

• Mesh by Element or Shape

• Mesh by Contours

• Mesh by Points

• Place Grid Mesh

• Developable Mesh from Curves

Mesh from Element

The Mesh from Element tools allows you to convert any surface or solid to a mesh element. Tolerance settings control the accuracy of the shapes/mesh compared to the original surface or solid.

• Output: Lets you select the type of element to be constructed:

• Mesh Element — The constructed element is placed in the design as a single mesh element.

• Shapes — The constructed element is placed in the design as polygons in a graphic group.

• Chord Tolerance: If on, lets you define the maximum distance from the constructed polygon to the original (curved) element it approximates.

• Angle Tolerance: If on, lets you define the maximum angle allowed between adjacent facets on a smooth surface. Lower angle tolerance allows for a finer mesh.

• Max Edge Length: If on, lets you define the maximum allowable edge length for any facet in the constructed element. Shorter edge lengths results in a finer mesh.

• Max Number Edges: If on, lets you define the maximum number of edges for any facet in the constructed element.

• Keep Original: If on, the original element is retained.

Feb-09 429 MeshesCopyright © 2009 Bentley Systems, Incorporated

Creating a Mesh

Exercise: Creating Meshes from Elements


User: untitled


2 Open Surfaces.dgn.

3 Open the 02_Mesh Study model.

There are 5 spheres with a radius of 0.5.

4 Select Construct Mesh (Z + 1 + 1) with the following tools settings:

Chord Tolerance: 0.25

5 Reduce the chord tolerance to 0.125 and select the next sphere.




As you decrease the chord tolerance you create a finer mesh

When the mesh is created it is created on the active level and not on the level on which the data resides. A best practice is to create the data on one level and the mesh on a separate level to retain control of the data.


Creating a Mesh

Mesh By Contours

The Mesh from Contours option is useful for existing contours. The contours do not need to be closed to create the mesh. Use the Element Selection tool to select all the elements that you want to be included in the mesh. The Expand to Rectangle tool setting creates a rectangle at the lowest contour elevation.

Exercise: Creating a Mesh from Contours

1 Continuing in Surfaces.dgn, open the model 03_Mesh from Contours.

2 Use Element Selection to select all the contour elements or press Ctrl + A.

3 Select Mesh (Z + 1 + 2) with the following tools settings:

Expand to Rectangle: Enabled

4 Enter a data point in a view.

The reason that you create a Mesh Boundary and do not use the contour is that the contour is usually a B‐spline and will create gaps if used for the bottom surface. By extracting the boundary of the mesh the exact shape will be used to create the bottom with an exact fit. The Boundary tool will create a series of line elements in the same graphic group so it is best to have the graphic group lock on.

Mesh by Points works the same as using Contours. Typically you would get this data from an external source instead of creating a collection of points. For example, from Import XYZ data or CloudWorx.


Modify Mesh

Place Grid Mesh

The PLace Grid Mesh is used to manually place a mesh element by defining points of a grid. If both Close Row (U) and (V) toggles are enabled, the mesh closes itself to form a volumetric mesh.

How to place a grid mesh:

1. Select Place Grid Mesh tool.

2. Enter a series of data points to define the first row (in the u‐direction).

3. Reset to complete the first row.

4. Enter more data points to define other rows. After the same number of data points is entered, as is in the first row, the row is completed and a new row is started.

5. At the completion of the final row, Reset to complete the mesh element.

Developable Mesh by Curves

This tool is used to create a mesh approximation of the developable surface between two curves. The generated mesh will consist of quadrilateral facets. You then can use the Unfold Mesh tool to lay the mesh onto a plane.

Modify Mesh

Several tools are available to modify an existing mesh.

Mesh Booleans

Meshes can be combined to create volumes or larger mesh surfaces or they can be subtracted from one another. The Mesh Boolean tools help with this.

The tool settings are as follows.

• Union ‐ Union 2 meshes.


Modify Mesh

• Intersection ‐ Find common volume between 2 meshes.

• Difference ‐ Subtract on mesh from another.

• Project onto mesh ‐ project a profile onto a mesh.

The following exercise is an example of a site project with an existing terrain and a finished terrain. The 2 can be combined to calculate the volume of material that will be removed or added.

Exercise: Using Mesh Boolean tools to create a completed site

1 Continuing in Surfaces.dgn, open the model 04_Existing Terrain Mesh.

2 Select the Visualization Task.

3 Select Light Manager (W + 1). Enable Solar and Solar Shadows.

4 Select the Render tool (Q + 1) with the following tool settings:

Target: View

Render Mode: Ray Trace

5 Enter a data point to render the view.

6 Turn on the level BuildingSiteMesh.


Modify Mesh

The green mesh is the proposed site mesh and that it extends above the existing terrain. You can subtract the green mesh from the yellow mesh to create the finished site mesh.

7 In the Surfaces task, select Mesh Intersect (Z + 2 + 2).

8 Select the yellow mesh and then the green mesh.

9 Enter a data point to accept.

If you execute a mesh difference you will receive a volume that is the soil volume that will be removed.

Exercise: Using Mesh Boolean Subtract

1 Continuing in Surfaces.dgn, in the model 04_Existing Terrain Mesh.

2 Edit > Undo the previous command.

3 Select Mesh Subtract (Z + 2 + 3).


Modify Mesh

4 Select the yellow mesh and then the green mesh.

5 Make the Drawing tasks active in the Task Navigation dialog.

6 Select Measure Volume (9 + 6) and enter a data point on the newly created mesh.

The volume is 459602.8064 cubic meters.

Combining Feature Models and Meshes

Suppose that you are building a bridge and need to calculate the volume of concrete needed for the bridge pier on bedrock. The rock surface is known and you have a DTM model of it. You know what you want for the pier, but modeling that in relation to the rock is not easy.

You can create the pier with a Feature Model tool and extend it through the DTM or the mesh. Use boolean subtract to remove the bottom of the pier by selecting the mesh. Measure the volume of the remaining feature model and you will have a true volume.

There is no need to convert the Feature Model to a mesh. You could do that but the results will not be as accurate. If the Mesh is too fine you may be looking for too much accuracy with the mesh. In that case you either convert the Feature Model to a mesh or reduce the accuracy of the mesh model with the Decimate


Modify Mesh

Mesh tool. This will reduce the accuracy of the bedrock but not the accuracy of the feature model.

Other Modify Mesh tools

Used to reduce, stitch, split, simplify, unfold, reverse, or extract the boundary of an existing mesh element. Tool settings are as follows.

• Sub‐Division Mesh: Used to take an existing mesh element and create a new mesh that is smoother than the original.

• Decimate Mesh: allows you to reduce the mesh accuracy with the tool.

• Stitch Mesh: will combine mesh elements into a single mesh.

• Split Mesh: will divide a mesh element into parts.

• Clean Up Mesh: will simplify a mesh (remove superfluous facets)

• Reverse Normals: will reverse the surface normals of a mesh element.

A simple workflow would be as follows.

1 Create contours.

2 Create Mesh.

3 Extract boundary.

4 Extrude to form sides.

5 Convert extrusion to mesh (Mesh from Element)

6 Stitch mesh and sides.


Modify Mesh

7 Boolean to add bottom.

8 Compute volume.

Exercise: Using the Decimate Mesh tools

1 Continuing in Surfaces.dgn, open the model 05_Building Site Design Mesh.

2 Select Element Information and click on the mesh.

3 Expand the Geometry tab to see the face and vertex count.

4 Select Clean Up Mesh (Z + 2 +9).

5 Select the green mesh and enter a data point to accept to see results.

6 Use Element Information to review the changes in face and vertex count.

7 Select Edit > Undo and experiment with the other Modify Mesh options.

Exercise: More Decimate Mesh tools

1 Continuing in Surfaces.dgn, in the model 05_Building Site Design Mesh.

2 Select Decimate Mesh (Z + 2 + 6)and set the following tool settings:

Percent of Reduction: 30


Mesh Utilities

Chord Tolerance: 0

Maintain Boundary: Disabled

3 Following the status bar prompt, select the green Building Site Mesh and accept.

4 Select Mesh Subtract (Z + 2 + 3).

5 Click on Existing Terrain and Building Terrain.

6 Make the Drawing tasks active in the Task Navigation dialog.

7 Select Measure Volume (9 + 6) and measure the volume.

Note the difference in volume from the last calculation.

8 Make the Surface Modeling tasks active in the Task Navigation dialog.


You can work with 3D Studio, or *.3ds, files in MicroStation and when a Google Earth images is captured by MicroStation the image is placed in the DGN file as a mesh. To use the 3DS file format, select File > Open then List FIles of Type > 3DS. THe 3DS file format is read‐only and can be saved to DGN. You cannot save a DGN to a 3DS or edit a 3DS file.

Mesh Utilities

• Unfold Mesh ‐ Will unfold a mesh element into a flat pattern. This will not take the place of sheet metal unfolding. The unfolding or flattening is by a random face instead of a selected face.

• Extract Boundary ‐ Will extract a mesh element outer boundary. Useful to extract and extrude down to create a solid base.

• Convert Mesh to Surface ‐ Used to convert a mesh element to a B‐spline surface. The mesh element should be of the kind that does not wrap around. Typically, meshes that are used to represent digital terrain models are good candidates for this too


Module Review

Module Review


Questions

1 Name 3 ways to create meshes.

2 True or False: When the mesh is created it is created on the level that the data is on.

3 How can you calculate a volume?

4 How can you get a face and vertex count for a mesh?

Answers

1 By Element or Shape, by Contours, by Points.

2 False. When the mesh is created it is created on the active level and not on the level that the data is on.

3 Use boolean subtract. Select Mesh Boolean and click the Mesh Subtract icon in the tool settings.

4 Select Element Information and click on the mesh. Expand the Geometry tab to see the face and vertex count.


Visualizing a 3D Design

Module Overview

When you work on a 3D model in wireframe display mode, you can see through the model. This is useful when you want to snap to an element that, in reality, would be hidden behind another.

You become accustomed to viewing designs in wireframe display. But when you want to check a design, it is often helpful to use MicroStation’s rendering display modes. These tools let you see models more realistically and include options for creating perspective views, as well as views with hidden lines removed and rendered images.


• Basics of MicroStation 3D view control

Module Objectives


• Use the updated visualization features of MicroStation V8i

• Change View Perspective

• Camera Settings

• Render a view

Feb-09 441 Visualizing a 3D Design





Questions

1 What is rendering?

2 Why would you apply materials to elements?

Answers

1 It produces an image of a 3D model that looks more realistic than a wireframe image. Includes hidden line removal and surface shading.

2 To apply color, texture, transparency, and finish to surfaces.

Luxology Technology

The Luxology Technology Preview provides a hands‐on preview of Luxology's rendering engine. In this preview, you can choose Luxology as the render method and launch a separate process that renders the images. Because Luxology rendering occurs outside MicroStation, you can continue to work with MicroStation during the rendering process. The Luxology‐licensed rendering engine will eventually replace the current rendering engine for all high‐end photorealistic rendering.

Visualization Toolbox

The Visualization section has been revamped with all tools reorganized into six toolboxes that are accessed from the Visualization toolbox.

Rendering

• The display/color modes settings for Radiosity now look like those for Particle Tracing. The Intermediate/Final display options have been removed and a new toggle has been added for Ray Trace Specular Effects.

• Brightness slider added for Smooth and Phong render modes.

Visualizing a 3D Design 442 Feb-09Copyright © 2009 Bentley Systems, Incorporated


• A new option in the Ray Tracing settings dialog lets you set brightness mode to either Adapt to Brightness or Brightness Multiplier.

• Smooth shading (in hardware) now supports shadows. That is, you can set the Display Style to display as Shadowed (Smooth shading with shadows).

• Hardware shadows are possible using the following Display Styles: Illustration with Shadows, Monochrome with Shadows, and Transparent with Shadows.

• Smooth shading supports shadows

• The Render Setups dialog has been reorganized. It has been consolidated into a single dialog with basic and advanced options.

• All rendering tools and dialogs let you select Render Setup.

• Distributed Rendering now is included and does not have to be downloaded as a separate package. Its basic requirement is that all processors taking part in the rendering have access to all the DGN, texture, RPC, and raster files to be used in the rendering. It is also necessary that all processors taking part in the rendering have access to the output path.

Lighting

• Changes to the way that lighting is processed means that lighting levels are now consistent across all render modes from Smooth to Particle Trace.

• Solar lighting is now consistent across all render modes. Note that Sky Lighting is not yet supported for Smooth.

• Ambient and Flashbulb intensities now defined in Lux (lumens per square meter)

• Ambient and Flashbulb intensities now have a physical value, Lux.

• Light Manager, consolidates all lighting controls into single dialog

• Light Setups store all lighting settings in DGN or DGN Library

• The Light Setups dialog lets you create different lighting conditions with the lights in the model. That is, you can create setups that have different light states, such as on/off or changes in intensity (dimming), or with the same lights having different settings, such as the difference between day and night conditions. The position of the brightness slider for all render modes can be stored in a light setup.

• The Get Latitude and Longitude from Google Earth icon in the Light Manager lets you obtain Latitude and Longitude settings by Ctrl + clicking on the required location in Google Earth.

• Physically based Sun and Sky color can now be determined from sun position (and also can be used as the environment).

Feb-09 443 Visualizing a 3D DesignCopyright © 2009 Bentley Systems, Incorporated


• A new improved Place Light tool incorporates all the settings required for the various light sources and Sky Openings. It provides better visual feedback, particularly for placing spotlights.

• You now can reposition and/or target directional light sources using their handles. To do this, you use the Element Selection tool to select the required light source and then drag the handles for the position and target to their new locations.

• Rendering of area lights has been improved to increase performance.

• Distant Light sources now are simple fill lights and are no longer treated as suns. They now

• can provide light in any direction, including upwards, under all circumstances.

• no longer have sky lighting applied to them (only Solar has this option).

• are not confined to sky openings when present.

• A new lighting view attribute, Default Lighting, has been added. When off, user‐defined scene lighting, any Global Lighting, (ambient, flash and solar) or Source Lights (area, distant, point and spot lights) will be used.

Materials

Enhancements to the Materials tools include changes to the default method of storing materials and multi‐layer material capability.

• By default, all palettes and their materials now are stored locally in the DGN. Where required, you still can convert or export the materials and palettes to external files.

• You can access material palettes from any DGN or DGN Library file. When you select Palette > Open from the Material Editor, you can select a DGN file to display the palettes contained within it.

• New mapping options, let you apply an image, gradient, procedure, or Operation (Tint or Gamma) to the Color, Translucency, Specular, Reflect, Finish, Opacity, and Bump channels. As well, each channel can be multi‐layered. The Material Editor lets you access the mapping option via icons for each channel.

• You can use the X, Y, (and Z for 3D procedures) lock setting in the Units definition for a material map to lock the image into the aspect ratio of the original image. When the lock is enabled, any changes to the X, Y, or Z settings


Rendering and Lighting

automatically is reflected in changes to the other settings to maintain the aspect ratio of the original image or procedural texture.

• The new Glow setting determines the amount of light the material appears to emit. For example, you can use this setting to simulate objects such as neon lamps.

Animation

• Animation now supports AVI and WMV video format output with user‐selectable codecs.


The Visualization task is only available in 3D models.

Visualization tasks are six separate tasks that can be accessed from the Visualization toolbox or the Visualization tasks.



Render Task

These tasks provide the rendering tool, Render Settings dialog, Light Setups dialog, single, multiple and panorama, render to image tools, and Query Illumination.

Lights Task

Provides ability to manage, place and setup lighting configurations.

Cameras Task

Used to setup a camera, define camera for manipulations, match photographs and set camera lens.

Materials Task

Used to define, apply, manipulate, query or preview materials, and to manage environment maps.

Material Projections

These tools attach, edit, match, create projection groups, and remove material projection.

RPC Tools

Ability to place and edit RPC cells.



Rendering and lighting settings

With the DirectX graphics and rendering engine, when you render a view (including saving images to disk and plotting), software rendering still is used for modes of Phong and above. For the rendering modes of Smooth and lower, however, hardware rendering is used.

• Render by Fence ‐ Includes ray tracing, radiosity, and particle trace.

• Rendering settings and Lighting setups have been consolidated. The Render Setups dialog has been consolidated into a single dialog with basic and



advanced options. All rendering tools and dialogs let you select the Render Setup or Light Setup by selecting the magnifying glass in the Tool Settings.


The Render Tool

The Render Tool

Rendering as a design aid

Working in wireframe display mode, you may get confused as to the orientation of the view. For example, you may be working in closely on a particular part of the model. When you zoom out, you may not be able to determine the correct orientation. In these cases, rendering the view can quickly solve the problem.

Rendering lets you see models as they would appear in real life. It is the process by which MicroStation can show you a photograph of a design. The Render tool provides a number of options for displaying designs on screen. These screen displays are only temporary. Updating the view returns it to the default view display mode.

To form the display, MicroStation first decomposes the wireframe model into a polygon mesh in memory. It can then determine which polygons are behind others in a view, in order to present the model realistically. With the more complex rendering modes, you can add lighting and material definitions to help make the image look even more lifelike.

The Rendering tool is available in each view control tool bar. Right click on any tool in the tool bar to turn it on.

Basic rendering modes such as Hidden Line, Filled Hidden Line and Smooth have been used with the View Display Mode tool. So you will now examine more complex rendering modes.

Rendering modes

While these rendering modes do not take lighting or materials into account, they can be useful during the design process to quickly check a design.

Exercise: Rendering views


User: untitled


2 Open Render_exercise.dgn from the class data set.


The Render Tool

3 Open the model 01_Ring.

This model contains a ring. It has been saved with 6 identical views open. You will use these to display the results of the various rendering options in order to compare the results.

As well as the elements, spot light sources have been placed in this model. This will become obvious when you look at the shaded rendering modes.

4 Make the Visualization task active in the Task navigation dialog.


Target: View

Render Setup: Phong_View1

Render Mode: Phong

Light Setup: Untitled

Antialias: None

6 Enter a data Point in View 1.

View 1 updates, showing the model in Phong render mode.

Hint: Phong rendering calculates the color of each pixel in a view, which requires more computation than Smooth rendering. The result is a more accurate shading in which the position of light sources can be more easily seen by their reflection in surfaces. Phong rendering optionally can generate shadows from a number of the light sources available. In addition, the gems have a single transparency value, no reflectivity and do not appear realistic.

7 Select the Render tool (Q) with the following tool settings:


The Render Tool

Target: View

Render Setup: Ray Trace_View2



Antialias: None


View 2 updates, showing the model in Ray Trace render mode.

Both Phong and Ray Trace provide more accurate shaded images, which can include shadows.

Ray tracing produces much more realistic images than those you have seen previously. With ray tracing, the image is generated by simulating the recursive reflection of light rays in the selected view. Even with this primitive design, you will see that ray tracing gives a more realistic result, with shadows produced from the point light source in the lamp.

Note: When you use ray tracing, point light sources are capable of casting shadows if Shadow is enabled in the light source definition, and Shadows are turned on for the view in the Rendering View Attributes dialog.

9 Select the Render tool (Q) with the following tool settings:

Target: View

Render Setup: Radiosity_View3

Render Mode: Radiosity


The Render Tool


Antialias: None


View 3 updates, showing the model in Radiosity render mode.

Note: Radiosity solving is a technique that calculates the light that is reflected between diffuse surfaces. This technique is not technically rendering but a rendering preprocess lighting solution that can be rendered.Radiosity solutions are view independent.


Target: View

Render Setup: Particle Trace_View4

Render Mode: Particle Trace


Antialias: None


The Render Tool


View 4 updates, showing the model in Particle Trace render mode.

Radiosity and Particle Trace rendering options provide much more realistic images, particularly where the inter reflection of light between surfaces is important. Neither option is a rendering method, as such. Both create a lighting solution, which are then rendered with either Smooth or Ray Trace to produce the final picture.

Radiosity and Particle Tracing modes calculate the effect of lighting in the scene, including shadows and reflection of light from surfaces. For example, a white light reflected off a red wall would have a red tinge to it in real life, which Ray Tracing alone does not simulate. Without a Radiosity or Particle Tracing solution present, the Smooth and Ray Trace rendering methods only show direct reflection of light sources from surfaces

13 Select Utilities > Render > Luxology and a new window will open. At this time the new Luxology rendering capability works separate from MicroStation V8i. Set the following Luxology options:

Width: 395

Height: 421

View: Active

Background: Color

Setup: Luxology Exterior Draft Quality

Note: These Height and Width are only to create a rendering the same size as the other views in this exercise.


Antialiased Rendering

14 Enter a point in View 5.

The Luxology render application in the initial V8i release is modeless and coexists with the standard MicroStation view windows. The Luxology application is multi‐threaded, therefore you can continue working in MicroStation while the rendering process is in progress. This first release of Luxology is intended for evaluation and workflow testing only.


When you are producing final images, the antialias setting for Shading Type reduces the jagged lines that appear where an edge is not exactly horizontal or vertical on the screen. Antialias is available for all render modes except Wiremesh.

Antialiased images take longer to render than for the regular setting but the resulting image can be much better. Antialiasing quality is determined by the Antialiasing Quality setting in the Rendering Settings dialog. This, in turn, controls the Antialiasing Grid Size. If you select Custom as the Antialiasing Quality setting, then you can enter your own figure for the Antialiasing Grid Size.

For the standard rendering methods (up to Phong), antialiasing causes the view to be rendered multiple times. The number of times that the view is rendered is the square of the value for the Antialiasing Grid Size. If you change the Antialiasing



Grid Size to 4, the view will be rendered 16 times to create the antialiased image. With Ray Tracing a different system is used, where each pixel is sampled a number of times, depending on the Quality setting.

Jitter Samples allows you to take anti‐aliasing samples in a non‐uniform fashion.

Depth of Field allows varying of focus depending on distance from camera. Target of camera always remains in focus.

Exercise: Compare Normal and Antialiased

1 Continuing in the model 01_Ring in Render_exercise.dgn, select the Render tool (Q + 1) with the following tool settings:

Target: View

Render Setup: Particle Trace_Antialias_View5



Antialias: Medium


The view takes longer to render with antialiasing.

3 Compare View 2 with View 5.

Note, in particular, the difference along the edges of the gems where the jaggedness is very apparent in View 2, but has been smoothed out in View 5.


View Perspective

View Perspective

Rendering can help you determine the orientation of a view. You also have another option; using perspective. Perspective adds depth to a view, whether in wireframe mode or one of the shaded modes. You can use perspective to help you determine a view’s orientation.

By default, MicroStation displays views in parallel projection. There is no perspective displayed. When you are setting perspective for a view, you can use the preset perspective settings or interactively set your desired perspective. The perspective tools have changed in V8i and can be accessed in the View Tools, and View Control tools.

Exercise: Setting perspective dynamically for a view

1 Continuing in Render_exercise.dgn, open the model 02_Bridge.

2 Make View 2 the Active view

3 Select the Change View Perspective tool from either the View Control toolbox or the View Tools and select Extra Wide Camera.


View Perspective

4 Continue with View 2 as the Active View and select Normal Camera.

5 Continue with View 2 as the Active View and select Telephoto Camera.

6 To turn off the perspective in a view select the Camera off tool.

Note: When working with large models, where screen updates are slower, it may be more convenient to work with a Clip Volume.

Toggling perspective

When you set perspective in a view you are really creating a camera view, a view that is more natural looking, as you would see it through a camera viewfinder. Having set a specific or custom perspective in a view, you can toggle it using the


Render Settings

Camera settings. To disable perspective, you just disable the Camera View Attribute. This lets you retain the perspective setting for future use, and you simply turn on the camera for the view.

Render Settings

In the previous exercises you noticed that the Render Setup option in the Render Tool Settings used specific names rather than the Untitled option available in the drop down option list. Render Settings can be customized to specific parameters defined in the Render Settings dialog. In prior versions of MicroStation these were called General Settings under Settings > Rendering > General. All Render settings are in one dialog, Render Settings.


Render Settings

To access the Render Settings dialog use the magnifying tool in the Render Tool Settings or Settings > Rendering > Settings.

Included in the Render Settings dialog are various tabs for customizing your settings. For example the saved Render Setup, Phong_View1, only renders in the Phone mode.


Render Settings

Selecting the New Setup tool in the Render Setup dialog allows you to define a new setup and right clicking on a name allows you to rename a saved setup.

Shadows are controlled in the Render Mode Tab under the Raytrace category.

• Per Light ‐ Samples are controlled by the shadows setting for each light source.

• Sharp ‐ Number of samples 1.

• Soft ‐ Coarse ‐ Number of samples 16.

• Soft ‐ Medium ‐ Number of samples 64.

• Soft ‐ Fine ‐ Number of samples 160.

• Soft ‐ Very Fine ‐ Number of samples 256.

For transparency to display, it must be on in both the Render Settings dialog and the View Attributes dialog.

Each material also has a shadows setting, as do the light sources. You can specify that materials and light sources not cast shadows.


Render Settings

Stroke Tolerance

This tool is now located in the Render Settings on the All Settings tab under Render Mode. This setting has a direct effect on the time taken to render a view,

as well as the accuracy of curved surfaces. When the system first decomposes the model into a mesh of polygons, the deviation of the polygon mesh from the original surface is controlled by the Stroke Tolerance, which affects the quality of rendered images as follows.

Larger Stroke Tolerance values reduce processing time but the rendered curved surfaces can be farther away from the original surfaces. This is most noticeable around the edges of surfaces.

Smaller Stroke Tolerance values increase processing time but the rendered surfaces are closer to the original. These views take slightly longer to render, but the image is much better with the curved surfaces looking very smooth around the edges.

Generally, the default Stroke Tolerance setting of 0.500 is adequate for most images.

Shadows

For Ray Traced images, shadows may be generated by a number of the available light sources, as follows.

• Ray Tracing: Point Lights, Spot Lights, Distant Lights, Area Lights, Solar lighting and Sky Shadows.

While Phong rendering can also produce shadows, where accurate shadows are required, the Ray Trace option should be used. Phong rendering uses shadow maps, which approximate shadows. The accuracy of these shadow maps are controlled by the Shadow Filter Size and the Shadow Tolerance settings in the Rendering Settings dialog. In either case, you can render with or without shadows.


Render Settings

To display shadows in a rendered view for:

• Phong rendering: In the Rendering Settings dialog, enable Shadows for the view being used to create the rendered image. Shadows for Phong rendering can be enabled/disabled for each view individually.

• Ray Tracing: Shadows must be on, in the Render Settings dialog. Ray Tracing settings apply to all views.

Clearing Phong shadow maps

When you have shadows enabled for Phong rendering, the shadow maps are calculated the first time that you render the model. You can have these saved for future sessions by enabling the Save Phong Shadow Maps in the Rendering Settings dialog. This can reduce the processing time, but if you subsequently change the geometry in any way, then you should clear the shadow maps so that new ones are created. You do this by selecting Clear Shadow Map(s) in the Light Manager dialog under Lights > Clear Shadow Map(s). Alternatively, you can type LIGHT CLEAR.


Lights Task

Ray Tracing and shadows

With ray tracing, the shadows are calculated each time you render a view. If you change the model in any way or turn off the display of elements, the changes are taken into account and correct shadows produced.

Lights Task

Lighting is a key ingredient to producing rendered images of your design. If you have no lighting, your rendering appears as a blank view. MicroStation gives you the choice of 2 classes of lighting, Global and Source lighting. You can use either or both to illuminate your model. Source lighting consists of special lighting cells, which you place in your models, while Global lighting is defined entirely from a dialog.

Lights are calculated with true physics so they diminish in intensity over distance.

Default Lighting

Default Lighting consists of a shadow casting light over the viewer’s shoulder, plus some ambient and a flash. This lighting is ideal for modeling in 3D, as it always provides very good illumination of a model relative to the observer. Because


Lights Task

Default Lighting is a view attribute, you must enabled it to be used to illuminate your model.

To use Default Lighting, you must enable it for any view(s) where you want use it. This is done by clicking the Adjust View Brightness tool on the view border and turning on the Default Lighting toggle. When the Brightness tool is clicked, you will see a brightness slider and a toggle for enabling Default Lighting; checking the option turns on the Default Lighting for the view. The icon on the Adjust View Brightness tool changes to reflect the current state.

When the Display Mode of a Display Style is Shaded, that is, anything other than wireframe and hidden line, then the hardware renderer uses Default Lighting or the user‐defined lights (Scene Lighting), depending on the Default Lighting view attribute.

If a Light Setup other than From View is chosen, the Render tool overrides this view attribute and uses scene lighting.

When using the Render tool, to see the effects of Default Lighting, turn on Default Lighting for the view you are rendering; make sure that Light Setup: From View is chosen. To render a view using scene lighting, you can chose any light setup other than From View, or render a view with Default Lighting off. If you choose Light Setup: From View and enter a data point, the current state of the view attribute Default Lighting for that view determines which lighting is used.

Light Setups

This dialog allows you to create custom lighting setups using Ambient, Flashbulb, Solar, Sky Light or Source Light combinations. Brightness modifications made to either the Render tool or the Adjust View Brightness tool, in the View Tools, directly changes the Display Brightness in the Light Setups dialog. The highlighted Light Setup will turn blue, indicating a change was made. Click on the Save Setup tool or File > Save to capture these new changes.


Lights Task

Light Manager

This dialog is used to turn on and off light type or make property changes to Brightness, Ambient, Flashbulb, Solar, and Sky Light lighting.


Global Lighting

Global Lighting

Global lighting affects all elements in a file.

Ambient

Ambient lighting affects every element in the model. It adds lighting equally to all elements. As you increase the value of Ambient lighting, the amount of contrast diminishes. Ambient lighting is useful for illuminating surfaces that would not otherwise receive light. No shadows are cast by Ambient light. Settings for this light source let you adjust its Lux, Color, and Temperature.

Left image has only ambient light with no reflections and right image has light color modified.


Global Lighting

Flashbulb

Like a flashbulb on a camera, this light source illuminates all elements that are facing the viewing position or camera. Useful for checking models during construction, you also can use it to add light to a final image. No shadows are cast by this light source. Settings in the Global Lighting dialog, let you adjust the Lux, Color and temperature of the Flashbulb.

Flashbulb displays light from spot lights reflected from road.

Solar

Used to simulate lighting from the Sun, Solar lighting has settings that let you set any of the following:

• Latitude, longitude, time and date of the rendering.

• Solar Direction Vectors of the sunlight.

• Azimuth Angle and Altitude Angle of the Sun.

You can input this data manually in the appropriate fields, or you can use dialogs to select a city from a list or pick a location from a map of the world. These dialogs are opened by clicking one of the following options in the Location section of the Global Lighting dialog:

• Cities — opens the Location By City dialog from which you can select a city from the list.

• Map — opens Google Earth. Enable View > Grid to display longitude and latitude and View>Show Time>Automatically. With this method, you must still enter the GMT Offset manually.

• Zones — opens the GMT Offset By Time Zone dialog from which you can select a time zone.

Optionally, you can turn on Solar Shadows to view the effect of shadows generated by the Solar lighting (sunlight) when rendering with the Phong or Ray


Global Lighting

Trace options. As with other Global light sources, you can specify the Lux, Color and temperature of the simulated sunlight. Here are some examples for January

2009, city Philadelphia, USA.

Left image light parameters set for 9:00 AM, middle 12:00 noon and right image 5:00 PM.

Exercise: Setting the Flashbulb and Ambient lighting

1 Continuing in Render_exercise.dgn, open the model 02_Bridge.

2 In View 2, turn on the Background View Attribute.

3 From the Visualization Tasks, select the Light Manager tool (W + 1), or from the main menu bar, select Settings > Rendering > Light Manager.

4 In the Light Manager dialog, set the following:

Display Brightness: Adapt To Brightness = 1.00

Select Button: Side of Bridge (point for middle of brightness range)

Ambient: Disabled

Flashbulb: Enabled

Lux: 200

Solar: Disabled

5 Select the Render tool with the following tool settings:


Global Lighting

Target: View

Render Setup: Untitled

Render Mode: RayTrace


Antialias: None


The view is ray traced but it is quite dark.

7 In the Light Manager dialog, enable Ambient and set its value to Lux = 7.


The appearance is much brighter. Ambient lighting has added illumination equally to all elements in the view.

Exercise: Setting Solar lighting

1 Continuing in Render_exercise.dgn, in the model 02_Bridge, in the Lighting Manager dialog, set the following:

Ambient: Enabled set to 7

Flashbulb: Disabled


Global Lighting

Solar: Enabled

Intensity: 3

Shadow: Enabled, Sharp

Resolution: 0

Cloudiness: 0

Air Quality: Rural, 2.50

Type: Time & Location

Date: 2/1/2009

Time: 12:00 AM

Select Philadelphia from the list of cities and, in the Time section, set the following:

Time: 12:00 PM, Standard

Date: September 27

Year: 2007

2 Use the Render tool to ray trace View 4.

3 Click Cities and select Melbourne as the city.


Source Lighting

4 Ray trace View 3.

5 Note that the light intensity has changed along with the shadow length and direction.

Source Lighting

Unlike Global Illumination, which is controlled solely from a dialog, Source lighting consists of light sources in the form of special cells that you place in the design. This is done with the Define Light tool, which you will look at shortly. First, a brief description of source lighting.

Source lighting cells are stored in the cell library lighting.cel, which is accessed automatically by the Place Light tool. You do not have to attach this cell library before placing light sources. The Place Light tool has various settings for each light source type, which you enter prior to placing the light source. The same tool lets you modify them, if necessary, at a later date. The cells consist of construction class elements and are placed by default on level Default.

Shadow generation from source lighting

Not all rendering modes support the generation of shadows, even if the Shadow setting is enabled in the light source and for the view. For general rendering, only Phong and Ray Trace modes support the generation of shadows. Where Radiosity


Source Lighting

solving or a Particle Tracing solution is used, Smooth rendering also can display shadows.

Place Light tool

Source lighting provides a choice of 4 lighting types; Point, Spot, Area, Directional and Sky Opening. These light sources provide lighting as follows.

Point

Similar to a light globe, point light sources radiate light in all directions, from a point light source. Shadows can be generated by this light source in Ray Trace rendering only; they are not supported by Phong rendering.

Spot

Directional light source that behaves similar to a flashlight. Spot Lights have a conical beam. This can be defined to taper off to zero at the edge of the beam. You can define the Cone Angle for the beam and a Delta Angle through which the


Source Lighting

beam reduces from full intensity to zero. Shadows can be generated by this light source for Phong and RayTrace rendering.

Area

Created from existing polygons in the design, these light sources are useful for simulating fluorescent lighting, for example.

Directional

Directional light source that produces parallel light rays throughout the design, similar to sunlight. It does not matter where in the model that you place one of these light sources, all surfaces that face the direction of a Distant light source are


Source Lighting

illuminated by it. Shadows can be generated by this light source for Phong and RayTrace rendering.

Sky Opening

Used with Ray Tracing, Radiosity solving, and Particle Tracing, to generate more efficient solutions for indoor scenes lit with Solar Lighting, Sky Light, or Distant Light sources, through an opening in a wall or ceiling. Rather than consider the entire “sky” for calculating the lighting effect, only the lighting that is visible through the opening is considered.

Each source lighting cell that you place in a design can have different settings for such things as Intensity and Color. You can specify whether or not they cast shadows for the supported rendering modes.


Source Lighting

Place Light tool settings

You use the Define Light tool to create and modify light sources in your design. You can open the Global Lighting dialog using the Global button in the tool settings.

Tool settings for the Define Light tool are as follows.

Tool Setting Effect

Preset • Option menu that lets you select from a list of predefined lights.

• Presets available for Point, Spot and Area lights.

Name Text field that lets you define a name for the light source that you are creating.

Giving light sources unique names helps you identify them if you want to modify them in some way, or delete them. Where no name is input, the light is given a default name that identifies the type of light source. Where there are other light sources present of the same type, with the same name, then the name is incremented. For example, Spot Light, Spot Light (1), Spot Light (2), and so on, for Spot Light sources.

Color Opens the color dialog, which is used to specify a color for the light source.

Temperature Option menu that lets you assign a color temperature to the light source.

Intensity Sets the intensity of the light source (default is 1.0) for standard rendering (up to Phong). For radiosity, particle tracing, and ray tracing, that use real world lighting, acts as a multiplier to the Lumens setting.

Lumens Sets the light source brightness, for use with ray tracing, radiosity solving, and particle tracing. Acts as a multiplier of the light source's Color and Intensity values to simulate real world lighting values. This value, when multiplied by the Intensity of the light, specifies the overall brightness, in Lumens.

Bulbs Lets you assign multiple bulbs, with the defined settings, to the light source.

Cell Size (Distant, Point, and Spot Lights only) Sets the size of the light cell, in master units.

Bulb Size (Point Lights and Spot Lights only) Sets the size of the light source.

For soft shadows calculations, the ray tracing process assumes a default size of 12 inches for all point and spot lights. This can cause unnatural lighting in situations where light sources are placed within fixtures, where the fixtures are expected to cast shadows. For these situations, you can change the default size with this setting.


Source Lighting

In the following example you will add light sources to a design and check the effects by rendering the view. To place the light sources, you will use AccuDraw to position the required points in 3D space.

Exercise: Place an Area light source as a fluorescent ceiling light

1 Continuing in Render_exercise.dgn, open the model 03_Lighting Model.

View 2 is a camera view that has been set up for rendering. Views 1, 3 and 4 have been set up to simplify adding the light sources.


Currently, the Light Manager has Ambient and Flashbulb enabled for illuminating the scene.

3 Enable the Solar light in the Light Manager dialog with the following settings:.

Shadow If on, the light source can cast shadows in a Phong, or Ray Traced, rendered image, as well as with a Radiosity solution, or a Particle Traced image.

In Phong rendered images, only Distant, Area, and Spot lights can cast shadows.

In Ray Traced, Particle Traced, or Radiosity rendered images, all light source types can cast shadows.

For Ray Tracing, sharpness of the shadows is controlled by the Shadows setting on the Render Mode tab of the Render Settings dialog when mode is set to Ray Trace. If, however, Shadows is set to Per Light, then the sharpness of the shadows is controlled by the individual light source's Shadow option menu setting. This determines the number of samples used to calculate the shadows.

Sharp — Number of samples — 1Soft ‐ Coarse — Number of samples — 16Soft ‐ Medium — Number of samples — 64Soft ‐ Fine — Number of samples — 160Soft ‐ Very Fine — Number of samples — 256Custom — Appears when an existing light source has a number of samples that differs from those listed above.

IES Data If on, and an IES file has been selected, then IES data is used in the calculation of the light from the light source.

Rotation Lets you enter a value to rotate the photometric characteristics for the IES light source.

Cone Angle Spot Light only) Sets the angle of the beam cone of a spot light source. Used to “focus” the beam.

Delta Angle (Spot Light only) Sets the angle, at the edge of the beam cone, through which a Spot Light beam falls from full intensity to zero.

Tool Setting Effect


Source Lighting

Intensity: 15

Shadow: Sharp

Date: 7/21/2009

Time: 09:30 AM

City: Philadelphia

4 Select Place Light (W + 2) with the following tool settings:

Name: Flourescent1

Intensity: 80

Lumens: 1000

Shadow: Soft‐Fine

5 In View 4, identify the block element inside the overhead fluorescent light, and indicate the direction. Any direction is ok at this time, you will change direction later.


Source Lighting

6 Repeat step 5 for the second overhead fluorescent light and name it Flourescent2. The following is an image of the data in the Light Manager.

7 In the Light Manager dialog enable the Highlight icon. Enabling this icon will permit you to select the lights from the Light Manger dialog and have them display their edit handles.

8 Select Flourescent1 in the Light Manger dialog, and the Area Light is available for editing, in all views. Select a light handle and drag it to a point in the scene to determine the lights direction.

9 Repeat for flourescent2 and change the target to the furniture.

Note: Light Direction can be changed at any time by selecting the light source using the Element selection tool and adjusting the light target handle or by enabling the Highlight tool in the Light Manager and selecting the light source name.


Source Lighting

10 Use the Render tool to Ray Trace render View 2.

When you placed the light source, you gave it a name if no name was given then the system would generate a default name, Area Light. Any additional point lights would default to Area Light(1), Area Light (2), and so on.

Naming light cells can help you later if you want to edit them. Using the Define Light tool, you don’t need to have light source cells displayed in a view, you can simply select them from the list.

Point light sources radiate light in all directions, you do not have to consider direction. With Spot Light lighting, a directional lighting source, you must define the direction in which the light is shining.

Exercise: Edit a light source

1 Continuing in Render_exercise.dgn, in the model 03_Lighting Model, select the Light Manager tool with the following tool settings:

Table Lamp: Enabled (Turn On)

2 Render View 2 with:




Source Lighting

4 To edit the Table Lamp select the Light Manager, select Table Lamp and change the following settings:

Preset: halogen 75W Bulb

Shadow: Soft ‐ Medium

5 To render the Table Lamp area rather than the entire scene, place a fence around the Table Lamp area. Render View 2 with Target set to Fence.

Left image shows fence placement and right image is results of render with fence as Target.

Note: Using a fence lets you try numerous iterations of light settings without waiting for entire scene to render. After you are satisfied with your settings then render the entire scene.


Source Lighting

6 Delete the fence, change your Render Target back to View and Render View 2.

7 Try various light settings. Enable all lights, change colors, Presets, Date, and custom Lumen settings.

Exercise: Rendering with Luxology

1 Continuing in Render_exercise.dgn, in the model 03_Lighting Model, select Utilities > Render > Luxology with the following settings:

Setup: Luxology Interior Good Quality

2 Select the Luxology Render tool from the dialog the scene will render in the Luxology View Window.


Materials

Materials

Few things add as much realism to rendered images as textures and materials. With material definitions applied to elements in your 3D model, instead of producing simple colored surfaces, realistic textured surfaces are displayed.

By default, MicroStation rendering assumes that each design file surface is made of a material with a smooth shiny surface, such as plastic. Material definitions let you specify that an element is water or wood or brickwork. When rendered, instead of seeing the plastic element, you see the specified material. Each material definition can include a pattern map and/or a bump map, as well as other settings determining the finish and transparency/translucency of the material. Pattern maps and bump maps are image files that are applied to surfaces during the rendering process.


Materials

Material and Projection Tasks

Minor adjustments have been made to the Materials portion of the Visualization tasks in MIcroStation V8i. Materials and Material Projections are in separate tasks and are highlighted below.

Pattern maps

A pattern map is an image file that is applied to an element. You can think of this in terms of wall‐papering a wall. When you render an element that has a pattern map applied to it, instead of seeing the element (wall) you see the pattern map (wall‐paper). MicroStation provides a large range of image files, in JPG and TIF format, that can be used for pattern maps. These are stored in the …\Workspace\system\materials\pattern folder. Additionally, you can use your own image files as pattern maps.

Bump maps

Like pattern maps, a bump map is an image file that is applied to an element. Where it differs from a pattern map is that a bump map applies roughness or texture to a rendered surface. While it is not mandatory for bump map images to be grey‐scale, quite often they are. MicroStation uses the contrast in the bump map image to calculate texture, or bumps, in the rendered image. As part of the material definition, you can vary the height of these bumps. This lets you use the same bump map image file, for example, to create cast metal from very rough‐cast through to nearly smooth.


Materials

Materials stored in DGN

By default, all palettes and their materials now are stored locally in the DGN.

Where required, you still can convert or export the materials and palettes to external files.

Material palettes can be used from any DGN or DGN Library

You can access material palettes from any DGN or DGN Library file. When you select Palette > Open from the Material Editor, you can select a DGN file to display the palettes contained within it.

Material tables

When you assign materials from a palette file to an element in a design, the assignment is stored in a material table. By default, material tables are given the same name as the design file but have a .mat suffix. Also, by default, material tables are saved in the same folder as the design file. You can save them with another name and in another folder, if you wish.

Material Tables can be stored in the DGN file itself so no external file is needed.

Hint: Using Element Selection is a quick way to find and change material assignments and attachments.

Material Map sizes locked to aspect of map image

You can use the X, Y, (and Z for 3D procedures) lock setting in the Units definition for a material map to lock the image into the aspect ratio of the original image. When the lock is enabled, any changes to the X, Y, or Z settings automatically is reflected in changes to the other settings to maintain the aspect ratio of the original image or procedural texture.

The Apply Material Tool

Using the Apply Material tool, you can:

• Assign material definitions to elements in the design file either by Color/Level or as an Attribute.


Materials

• Check the material that is attached to an element.

• Remove material definitions from elements in the design file.

• Preview how a material will look on an element.

When you select the Apply Material tool, the Apply Material tool settings opens. From this dialog, you can load palette files, apply materials or open the Define Materials dialog.

From left to right, the icons across the top of the Apply Material tool’s dialog let you select from:

• Assign by Level/Color — to attach a material to elements of a particular color(s) on a particular level(s) in the model.

• Remove Assignment — to remove an existing level/color material assignment from elements in the model.

• Attach — to “physically” attach a material definition to an element, or a face of a solid, in the model. This setting take precedence over level/color assignments.

• Remove Attachment — remove a material attachment from an element or the face of a solid in the model.

• Query — to check for a material assignment to an element in the model. With AccuSnap active, you simply hover the pointer over the element being queried, and a tool tip displays the assignment or attachment information.

• Preview — lets you preview the appearance of a material on an element in the model. This is a temporary assignment (in memory) to the selected element.

• Environment Maps — lets you assign environment maps to a model. These are image files that will appear in reflections in materials, or through transparent materials where normally the background color of the model would be seen.


Materials

Exercise: Apply Materials to the wall and floor elements

1 Continuing in Render_exercise.dgn, open the model 04_Materials 1.

2 Select the Render tool with Render Mode set to Ray Trace.

You can use Real World Lighting so that you can interactively adjust the Brightness and Contrast of the rendered views. The Walls and Floor do not have materials applied.

3 Select Apply Material (A + 2).

The Apply Material dialog appears. Note that the material table file name displayed on the Table button is the same as that of the DGN file.


Materials

4 From the Material option menu, select Walls.

5 If necessary, click the Assign by Level/Color icon then identify and accept the wall element.

6 Use the Render tool to Ray Trace the view, and use the Brightness and Contrast sliders to tweak the image as desired. The wall now is rendered as a cream colored wall.

7 Repeat the previous steps, applying the Floor material to the floor shape (red) element.

When you have applied material(s) to elements in the design, it is a good idea to save the material assignment table. Currently, the material assignments are in memory only. You will now save the material table to disk.

8 In the Apply Material tool dialog, click the Save button (to the right of the Table name field).

9 This material assignments table will be loaded automatically the next time that you open this DGN file.

You may want different faces of a solid to have different materials assigned to them. You can do this with the Attach option. This lets you specify that a face of a solid has a particular material, while the remaining parts of the solid still may have an assignment by Level/Color.


Materials

Exercise: Attaching a different material to faces of a solid

1 Continuing in Render_exercise.dgn, open the model 05_Materials 2.

2 Click the Attach icon in the Apply Material tool icon bar.

3 Click the Open palette icon.

4 Select the Brick palette.

5 From the Materials list, select brick back alley.

6 In View 2, identify each solid and select the each face of the table bases. Use Ray Trace and render View 2. Remember to use (Ctrl+) for multiple

faces.


Multi-Layered Materials

7 Open the palette Wood.

8 From the Materials list, select Flat Pine.

9 In View 2, identify the solid and select the table top and side faces.

10 Use the Render tool to Ray Trace View 2.

Multi‐Layered Materials

You can create materials that consist of multiple layers of pattern maps, bump maps, procedures, gradients, and/or operations (tint or gamma setting).

New mapping options let you apply an image, gradient, procedure, or Operation (Tint or Gamma) to the Color, Translucency, Specular, Reflect, Finish, Opacity, and Bump channels. As well, each channel can be multi‐layered. The Material Editor lets you access the mapping option via icons for each channel.

You can define the way that the pattern/bump maps are blended and you can assign a value for opacity, to allow one map to be seen through another.



Adding layers of pattern maps, lets you create more complex materials. For example, you can create a brick wall that includes 1 or more signs, or have a material with partial opacity.

You can add layers to your material definitions, with various blend modes. The layers can be toggled as required.

Warning: Multi‐layered materials are not backward compatible with MicroStation V8 XM Edition v8.9.2 and earlier.

Exercise: Creating and using Multi‐Layered Materials

1 Continuing in Render_exercise.dgn, in the model 05_Materials 2, from the Visualization task open the Materials Editor (A + 1).

2 Open the Brick node on the left pane and highlight the material brick back alley and click the Pattern Map icon.



3 From the top left click New Layer and select vent01.jpg.

4 Set the following:


Projection modes for Pattern/Bump Maps

5 In View 2 zoom in on the right side of front table and Render using Ray Trace.


Projection modes are assigned to elements, rather than the material. This lets you use the same material with various projection modes depending on the geometry.

Control projection modes using the Materials task.

Projection modes for materials

Several projection modes are available:

• Directional Drape ‐ Mapping is applied relative to the direction specified by the Orientation setting



• Cubic ‐ Mapping is applied in a cubic fashion relative to the geometry.

• Spherical ‐ Mapping is applied in a spherical fashion relative to the geometry.

• Cylindrical ‐Mapping is applied in a cylindrical fashion relative to the geometry.

Warning: Material projection modes are not backward‐compatible with MicroStation V8 XM Edition v8.9.2 and earlier.

Tools for controlling Material Projections

The Materials task adds 5 tools for handling material projections.

Exercise: Using Material Projections

1 Continuing in Render_exercise.dgn, open the model 06_Projections.

2 Assign the material ‐ Brick Aged to the geometry.

3 Render to see the results. Take note of the sphere.

4 Select Attach Projection (S + 1) with the following tool setting:

Method: Spherical

5 Enter a data point on the sphere.



6 Render to see result.

7 Repeat with the cylinder and Slab.

8 Select the Edit Projection tool (S + 2) with the following settings:

Select: Scale Projection

Attach To: Element

Mapping: Cubic

9 Click on the Arrows to select a variety of scale directions.


The Define Camera Task

10 Us the Remove Projection tool (S + 5) and remove the projection from the slab.

11 Make a copy of the slab and place it on the side of the original slab.

12 Attach a new projection (S + 1) to both of the slabs.

13 Edit the Projection scale of one of the slabs.

14 Select the Match Projection tool (S + 3) with the following settings:

Enable: Projection Scale

15 Select the slab that the projection scale was modified then select the other slab to match this project on this slab.


You can use this task to create, edit and modify Cameras for Rendering.



Setup Camera

The Setup Camera tool (E + 1) is designed specifically to set up views for rendering. When using this tool, a camera view is selected and you have the option of displaying its viewing cone in all other views that display the same volume of the design file. When this tool is selected you are prompted to select an active view. In this example View 2 the Right Isometric view is selected. You now have the option of selecting the camera position and target using any of the other open views. You can work in one view and use AccuDraw to manipulate the camera and target position. I

After an active view is selected you can then select the type of lens available from the options list and enable Camera Height, Target Height or select these positions using AccuDraw and AccuSnap on the view geometry.

Left image is starting view and right image is selecting camera and target position in top view.

Resulting image in view 2 the active view.



Define Camera

The Define Camera tool (E + 2)is used to control the movement and settings of the camera. You can manipulate the camera view cone in the other views or you can use the advanced tools from the Define Camera tool settings to manipulate the view camera.

With the Define Camera tool, you can manipulate the view cone using the handles that appear at the eyepoint, target, center and a fourth handle that lets you alter



the viewing angle. The target handle is located at the center of a rectangle that represents the image plane.

Using these handles, you can manipulate the view cone as follows.

• Camera handle — positions the camera or eyepoint relative to the target.

• Center handle — position the entire view cone without changing the relative positions of the camera and target.

• Target handle — positions the target relative to the camera or eyepoint.

• Viewing Angle handle — changes the viewing angle of the camera. Reducing the view angle is equivalent to using a telephoto zoom lens. Without moving the camera or target locations, you can zoom in or out by changing the view angle.

To change the position of a view cone handle

1. Enter a data point on the handle that you want to move.

2. Move the handle to the new location.

3. Enter a second data point to complete the change.

You can enter a data point on the handle and hold down the data button as you move the handle. Releasing the data button completes the move.

You need 2 views open to quickly manipulate the view cone. For example, you can use the Top view to manipulate the view cone horizontally and the Front or Right views to manipulate it in the vertical direction.

Camera Handle

Center Handle

Target Handle

View Angle Handle



Exercise: Using the Define Camera tool

1 Continuing in Render_exercise.dgn, open the model 07_Camera.

2 Select Define Camera (E + 2) with the following tool settings:

Continuous View Updates: Enabled

Display View Cone: Enabled

Projection: Three Point

You are prompted to Select active view.


This becomes the Active View, as shown in the Define Camera tool settings. The View Cone for the selected view appears in the remaining views.

4 Enter a data point on one of the view cone handles in View 1, 3 or 4. Zoom out if you have to.

5 Move the pointer and observe that the camera view (View 2) updates continuously as you manipulate the view cone.

If you disable Continuous View Updates, the view updates after you have moved the handle.

Try all the view cone handles to see how they relate to each other.

Using the view cone and a camera view in this fashion gives you visual feedback on just what the camera view is displaying. Currently, the Projection is set to Three Point, which displays the camera view much as you would see it through a normal camera.

Note: You can also manipulate the view by moving the cursor in View 2 and selecting one of the tool settings icons for specific actions. By clicking on, More, you can display windows to enter specific numerical data for camera manipulation.

Camera action options

There are 9 icons across the top of the Define Camera tool settings which let you control the camera view cone directly. These icons match options in the Camera Action option menu.



Exercise: Using a camera action tool

1 Continuing in Render_exercise.dgn, in the model 07_Camera, in the Define Camera tool settings, set the following:

Active View: 2

Projection: Three Point

Reference Point: Target

Continuous View Updates: Enabled

Display View Cone: Enabled

2 Click Pan.

3 Enter a data point at the center of the camera view (View 2).

4 Move the pointer:

Left/right to rotate the camera (eyepoint) left/right about the target point.

Up/down to rotate the camera up/down about the target point.

This is similar to moving around a stationary object (the target).

5 Reset to return the view to its original orientation.

6 In the tool settings, set Reference Point to Eye.

7 Move the pointer:

Left/right to rotate the target point left/right about the camera.

Up/down to rotate the target point up/down about the camera.

Camera Option Effect

Pan Move the camera or target radially relative to each other, either horizontally or vertically.

Pan Horizontal Move the camera or target radially (horizontally) relative to each other

Pan Vertical Move the camera or target radially (vertically) relative to each other.

Roll Roll or tilt the camera.

Dolly/Elevate Move the camera sideways or vertically.

Dolly Move the camera in, out, or sideways.

Lens Focal Length Change the lens focal length.

Lens View Angle Change the Lens View Angle

Pan/Dolly Walk through the view.


Saving Rendered Images

This is similar to standing in the one spot and turning your head left/right/up/down to view the surroundings.

8 Reset to return the view to its original orientation.

Try the other camera action options in the Define Camera tool settings.

Controlled Movement

You have the option to move or rotate the camera view cone by a defined distance/angle. To do this, you must disable Continuous View Updates and use data points to specify movement. The amount of movement or rotation per data point is specified in the Controlled Movements settings.

For view cone manipulation with data points, the position of the data point in the view determines the direction of the movement or rotation. If you think of the view as being divided into 9 sections, then the movement performed by a data point in one of these sections is as shown in the diagram below.

When you move the camera/target with Continuous View Updates disabled, each data point moves the camera view cone as specified by Distance. Similarly, if you rotate the view cone, each data point causes a rotation as specified by Angle.


Now that you can set up and create rendered images of your models, you might want to save one or more of them and impress your friends and clients by sending them a file containing the image. You can quickly save MicroStation images using the Save option in the Utilities > Image menu.



You have many choices when saving your images, such as file format, resolution and type of shading. As well as being able to save your images, MicroStation provides a viewing facility and a way to perform limited modifications.

There are many variables that you can adjust when saving images, however, you will find that most remain consistent once you begin to integrate images into your workflow.

These tools are found on the Utilities > Image menu. In addition to these basics you can also convert images, capture the screen as an image and save an image using multiple computers to speed up the processing time.

Saving a rendered image

To save an image, select Utilities > Image > Save, which opens the Save Image dialog.

• View controls which view will be rendered.

• Format controls the type of file format in which the image file will be saved. MicroStation supports a wide variety of file formats including JPG, TIF, TGA, Postscript, PCX and others.

• Compression selects the type of file compression for those formats that allow it. For example, if you select JPEG then you have the option of choosing High Loss (high compression) through to Minimum Loss (high quality).



• Mode lets you select the bit depth of the image or grey scale.

• Shading lets you select which type of shading to use. For high quality images that cast shadows, select RayTrace shading mode.

• Shading Types lets you select between Normal, Antialias and Stereo.

• Action is set to Ray Trace, Radiosity, or Particle Trace only. Sets the rendering action to be performed.

• Resolution controls how large an image you produce, in terms of pixels. Thought should be given to displaying the saved image. In order to display the saved image, you must have enough RAM on your video card to hold the image. This depends also on what bit depth (24 bit or 8 bit) you select in Mode.

When one of the Resolution values (X or Y) is adjusted the other updates to maintain the view aspect ratio. Using higher resolution allows you to have more pixels to work with, hence a finer quality image.

• Gamma Correction controls the white content of an image. The values range from 0.10 to 3.00. A value of 0.10 is very dark while 3.00 is very bright.

Image Size lets you control the output size of the image in pixels, or unit as well as how many dots per inch are recorded.

Banded Rendering allows for an image to be broken up into strips or bands for network rendering.

Distributed Rendering lets you process an image using 2 or more PCs networked together.

After specifying the settings for your image, you can save the image with a unique file name and place it on your hard drive. The default location in which MicroStation stores image files is the out directory, such as …\Workspace\projects\examples\General\out.

Viewing a saved image

MicroStation has a viewing utility that lets you view your saved rendered images and perform a number of editing and manipulation operations.

To view a rendered image, from within MicroStation, select Utilities > Image > Display.


Distributed Rendering

Distributed Rendering

You can use several machines to do one rendering or animation by using Distributed Rendering. Distributed Rendering now is included and does not have to be downloaded as a separate package. Its basic requirement is that all processors taking part in the rendering have access to all the DGN, texture, RPC, and raster files to be used in the rendering. It is also necessary that all processors taking part in the rendering have access to the output path.

Simplified setup for Distributed Rendering

Setting up this new version of Distributed Rendering is simple and it does not require any external database server as was required previously. To use Distributed Rendering, you must first launch the Distributed Processing Controller from the MicroStation start menu.

The first time that you start the controller, you are prompted to define your Shared (probably server) Directory. This determines where Distributed Rendering stores the information it needs to configure your controller and pass data back and forth between multiple machines. All machines that will participate in the rendering

How to set up Distributed Rendering

1. From the Start menu, select Bentley > MicroStation V8i > Process Controller for Distributed Rendering.

The Configuration Settings dialog opens.

2. To select a Shared directory, click the button to the right of the field.

3. Select a shared folder and click OK.

4. Click OK.


Module Review

5. When Distributed Rendering is available, the Bentley Distributed Processing Scheduler icon appears in the System tray.

Distributed Rendering Related dialogs

The Scheduler is accessed by right‐clicking the Process Controller tray icon and choosing Open Scheduler. The Job Monitor is accessed by right‐clicking the Process Controller tray icon and choosing Open Job Monitor.

Scheduler

The Scheduler dialog is used to schedule times that your system is available for contributing to processing images.

Job Monitor

The Job Monitor dialog displays the progress of your distributed rendering tasks.

Module Review


Questions

1 You can store different settings for an individual light with which tool?

2 True or False: You can specify that the materials for a DGN file be stored within the file itself.

3 True or False: Distributed Rendering requires another installation on top of MicroStation.

4 Name three global lighting types that can be used in rendered images.

5 What is the difference between Point light sources and Spot Light lighting?

6 True or False: Projection modes are assigned to elements, rather than the material.


Module Review

Answers

1 Light Setup.

2 True. Rather than using an external.pal file.

3 False. Distributed Rendering is part of the default MicroStation installation.

4 Ambient, Flashbulb and Solar.

5 Point light sources radiate light in all directions, you do not have to consider direction. With Spot Light lighting, a directional lighting source, you must define the direction in which the light is shining.

6 True. This lets you use the same material with various projection modes depending on the geometry.


Using Dynamic Views

Module Overview

The term dynamic views refers to a method of composing drawings that is a new approach to managing projects. Dynamic Views can help you to do the following.

• Automate drawing creation

• Keep MicroStation files up to date by creating responsive drawings and connecting Saved Views to models

• Eliminate errors in design and documentation

• Communicate design intent through models and drawings

• Manage changes across MicroStation files


• Understanding of design and sheet models

• Understanding of saved views

• Understanding of references

• Basic knowledge about detailing symbols

• Knowledge of clip volumes

• Understanding of Project Explorer

• Knowledge about display styles

Feb-09 507 Using Dynamic Views


Module Objectives

Module Objectives


• Organize project data

• Complete design composition

• Create dynamic saved views for use in sheets

• Complete sheet composition



Questions

1 What is a saved view?

2 What is a sheet model?

3 What is the purpose of Project Explorer?

Answers

1 A named view definition saved in a DGN file for later recall or for attaching to another model file as a reference.

2 A type of model that serves as an electronic drawing sheet. It typically consists of design model references that are scaled and positioned to create a printable drawing.

3 It is used to manage project data within MicroStation. Project data is stored in link sets in a DGN file or in a DGN library. A link set contains hierarchical information about links or grouped information in project data.

Using Dynamic Views 508 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Glossary

Glossary

Dynamic Views:

Dynamic views is a general name that encompasses several related technologies which share the goal of making model analysis and documentation interactive and intuitive. One of these technologies allows clipping of models and section graphics generation on the fly. Section views, detail views, and elevation views are types of dynamic views.

Through the use of detailing symbols with smart fields and links, you can create live, intelligent sections of a design composition that update automatically as the design evolves.

Annotation:

Complimentary information such as dimensions, text, notes, patterns, hatching, and detailing symbols. Annotation excludes design graphics. The size of annotations can be controlled by annotation scale.

Design:

A collection of elements in a design model that are drawn at full scale (1:1). A design is not intended to be a finished drawing for publication. A design encapsulates part of a project for active editing, and uses references for backgrounds only.

3D Design Composition:

A collection of referenced designs at full scale (1:1). The references are assembled using different level states and view attributes. Design composition is used to create saved views that will be used in sheets. In the 2D workflow, there is typically no design composition.

Drawing:

A collection of elements or references in a 2D design or sheet model, at full scale (1:1), which is used to create multiple sheets. This step includes static or common text that does not change. Annotation scale should be used here. This is an intermediate step between design composition and sheet composition.

Feb-09 509 Using Dynamic ViewsCopyright © 2009 Bentley Systems, Incorporated

Dynamic Views Overview

2D Drawing Composition:

A collection of referenced drawings at full scale (1:1), without a border, which is used to generate saved views.

Drawing Annotation:

Annotation that will be shown in multiple sheets, potentially at different scales, which is placed in a drawing.

Sheet:

The final output of the design process that can be delivered electronically or on paper.

Sheet Composition:

The process of collecting saved view references and placing items in a sheet model that defines a finished document that is ready for publication. This step is where references, including borders, are scaled to fit a sheet. Print output scale is always considered.

Sheet Annotation:

These annotations are specific to one sheet.

Drawing Title:

The annotation for a drawing or detail when placed in a sheet composition.


When a team of users works on a project, they typically work on separate files to allow multiple people to work at the same time. Members of the team work on different aspects of the project, and references are used to communicate graphic content across the team. One way to view a project is as a network of DGN nodes with references as the connections between them.



The dynamic view workflow creates a split editing environment. It lets you have evolving geometry that is reflected in each step of the process. Using this method, you separate annotations from geometry, creating reusable geometry. There will be flexibility regarding how much dynamic view functionality you use in a project. It may not be appropriate for all projects, or for all phases of a project.

Dynamic Views core technology is constructed on this model:

1. Make sure you have the right Display Styles.

2. Create your Clip Volumes

3. Create your Saved Views

4. Reference your Saved Views into the right Model, in the right File.

Take a picture, it will last longer

Saved Views are central to the composition strategy, and are therefore more prominent MicroStation V8i. You can think of it as taking a picture, then putting that picture into a photo album.

The first processes are spatial design. When you are in a design model with a black background, it is spatial design.



The following process is completed in a sheet model, which is a flat representation.

3D Design models compiled into one model, Drawing created by Saved View References, Sheets created by Saved View References

General workflows

There are simple and complex Dynamic View workflows, for example, a small 3D model straight to a sheet, bypassing the Drawing layer.

A simple 3D workflow is as follows:


Dynamic View Workflow Task


Critical to understanding dynamic views at first is to use the delivered Drawing Composition workflow. This Workflow Task is specifically designed to take you through the process from beginning to end. Tasks are arranged in the Tasks dialog from top to bottom.

There are several activities included in this workflow.

• Organize the project data. At this stage, you use Project Explorer, which is a catalog of your project resources or a hyperlinked Table of Contents.

Drawing is in every workflow. It is there to help you with any other drawing task with which you might be faced. It remains unchanged from the previous version.



• Design Composition. At this stage, you create a collection of references at full scale (1:1) to use in several designs, design compositions, or sheet compositions.

• Create Views (2D). At this stage, you compose all the section, detail or plan views in the project. These views should have linked callouts and placeholder fields so that, when the views are added to a sheet, they are automatically updated as work commences.

• Sheet Composition. At this stage, you create sheets that represent finished geometric work ready for publication. Typically, this is where print scale is taken into consideration.



• Annotate. Add final annotations such as any informational geometry, hatching, dimensions, callouts, and text to the sheet to produce a finished product.

The following is an exercise where you will create a Saved View from a Design File, then create a Sheet models and place the saved view in the sheet model.

Exercise: Create and place a Saved View

1 Open the file Drawing Composition_exercise.dgn from the Everything 3D data set.

2 Confirm view 1 is the top view.

3 In the Create Views task create a named saved view of the top view of the house.

Name: Plan



4 Now that you have a saved view you need to drag and drop the saved view into a sheet model. In the Sheet Composition task, select the New Sheet Model tool with the following tool settings:

Type: Sheet, 2D

Name: Plan

Description: Plan Sheet

Annotation: 1:20

Line Style Scale: Annotation Scale

Update Fields Automatically: Enabled

Sheet Name: EX 1 Kitchen Plan

Sheet Number: 1

Display Sheet Boundary: Enabled

Size: ISO A1

Note: A best practise is to keep the background color of Designs and Design Composition models as black. The black color will assist in differentiating designs from drawings since the default color of a sheet model is white.

5 Add border graphics to the sheet model. In the Sheet Composition task open References and attach the Border Model located in the Drawing Composition_exercise.dgn file. Set the following:

Model: Border

Detail Scale: Full Size 1=1



Scale (Master:Ref): 20:1

Now that you have a sheet Model and attached border, you place the Saved View, named, Plan onto the Plan Sheet.



6 Drag and drop the saved view “Plan” from the Saved View dialog to view 1 and enter a data point in the view.

At this point in the simple dynamic view process any changes to the design model is reflected in the saved view on the sheet model. The next step is to add annotation to the sheet model.

Exercise Create callout symbols in the sheet model

1 Continue with the Plan Sheet model in the Drawing Compositiion_exercise.dgn file.

2 Select the Annotate task, Place Section Callout tool (T + 1) with the following tool settings:

Create Section Views: Section 1

Flip Arrows: Enabled

Annotation Scale Lock: Enabled



3 Identify any element in the referenced saved view then place a start and end point for the section. Refer to the following image for approximate location of the section callout.

Note: Right clicking on a section callout is another way to flip the direction of the section arrow.

4 Now that you have a Section Callout you will create a sheet model for Sections.



Note: It is not necessary to create a new sheet to place section callouts they can also be placed in the Plan Sheet.

5 Select the Sheet Composition task and select the New Sheet Model tool with the following tool settings:

Type: Sheet, 2D

Name: Sections

Description: Section Sheet

Annotation: 1:20

Line Style Scale: Annotation Scale

Update Fields Automatically: Enabled

Sheet Name: EX 2 Kitchen Section

Sheet Number: 2

Display Sheet Boundary: Enabled

Size: ISO A1



6 Open the Saved View dialog and drag and drop the Section 1 view to the new Sections sheet model.

7 Now let’s test the dynamic saved view capabilities. Open two views, view 1 and view 2. In view 2 select the View Attributes dialog and open the View Setup option with the following settings:

Models: Sections



View 1 in left image contains the Section Callout symbol and View 2 in right image shows the placed saved view reference.

8 You will now move the Section Callout in View 1 and dynamically see the view change in the Sections Sheet. Select the callout with the Element Selection tool. Try different positions for the callout.

Exercise: Challenge Exercise, create a section callout with multiple corners.

Here is an example of a multi‐cornered section callout identified in the plan view, in the enclosed box.

Exercise: Challenge Exercise, create an Elevation callout in a new sheet named Elevations.



Here is an example with multiple elevations created from the plan view and placed in a sheet model named Elevations. Take notice of the Set Reference Presentation in the Reference dialog.

View Setup

If you open more than one view each view can display a different model contained, within the DGN file, using the View Setup option in the View Attributes dialog. The following is an example of multiple views with each view displaying a different model.



The following is the View Setup for the Active view, view 4.

Using multiple views is an ideal way to view the dynamic capabilities of Drawing Composition. Changing the design or original Saved View will dynamically change in their associated references.

A more comprehensive 3D workflow is as follows:

In a comprehensive 3D Dynamic View workflow relationships between all project disciplines are achieved.

Design Composition

In the design phase individual designs are shared via reference attachments. The individual designs with there associated references are referenced in a blank 3D design file called the Design Composition. Selected views, (Saved Views and Clip Volumes), are created in the Design Composition DGN file.

Drawing Composition:

The next phase of the workflow incorporates the Drawing Composition file where saved view references from the Design Composition file are attached along with



static annotation. In this phase additional Saved Views, Clip Volumes and Detailing Symbols are placed.

Sheet Composition:

Typically Saved Views from Drawing Composition or direct from Design Composition are placed here via the Drag and Drop technique. Also specific sheet annotation is placed here.

In the following exercise you will be guided through a more comprehensive Dynamic View workflow. The Dynamic View workflow is as follows:

Exercise 1: Create a Design Composition file with design references

1 Open the empty file Building Composition.dgn.

2 From the Drawing Composition Tasks select the Organize Task.

3 Click on the Open Project Explorer tool (Q) and expand Designs directory.

4 Drag and drop the following designs to View 2, Building Composition.dgn. Use the following dialog settings:

Column Enclosure [BSI300AE9‐Shell.dgn]

Core [BSI300AE9‐Core.dgn]

Structural Composite [BSI300S‐9‐Structural.dgn

Attachment Method: Interactive

Nested Attachments: Live Nesting

Depth: 99



All other settings: No changes

Column Enclosure [BSI300AE9‐shell.dgn]

On you system this Design Composition should have a black background

Note: A simple way to determine if your drawing is a design composition is it’s background color. The background color for a design or design composition should be black or some other color than white. The default color for a sheet model is white.

If you check your Reference dialog you will see that these designs have been placed as references in you Building Composition.dgn file.

Exercise 2: Create a standard Saved View from the Design Composition file

1 Continuing with the Building Composition.dgn file. Set view to Top view.

2 In the Design Composition Tasks select the Create Views task.

3 Select the Save View tool (R) with the following settings:



Name: Exercise‐2 Plan View

Description: Top view of Building Composition model

All other options: No change

4 Open the Saved Views dialog.

5 Expand the Saved Views directory in Project Explorer and right click on the Standard Views directory and select the Refresh option. This will display the new Saved View that you created.

Note: Get in the habit of doing this each time you create a new Saved View.



Exercise 3: Create a new Sheet file and place a standard Saved View

1 Continuing in Composition.dgn, activate the Sheet Composition task.

2 Select the New DGN file tool (Q) and navigate the \Drawings directory. Enter the following:

Seed: sheetseed.dgn

File name: Drawing Composition.dgn

3 Click on Save and the Drawing Composition.dgn file will open.

Note: The new sheet has a default name 1 to 100. The name comes from the sheet seed file. Open the Model dialog and Edit Model Properties to change the sheet model name to Plan View. Close than open your view to update your model name in view window.

This 2D Sheet File does not reside within the 3D Design Composition.dgn file. In the previous simple Dynamic View workflow the Sheet model was contained in the original 3D Design model.



4 Return to Project Explorer and expand sheets to see if the new file is displayed. If not then right click on the Sheets directory and select the Refresh option.

5 Navigate to Project Explorer and in the Saved Views directory expand Standard Views. Drag and drop the Exercise‐2 Plan View from the Building Composition.dgn file onto the Exercise‐3 Drawing Composition.dgn file in View 1.

Note: When you drag and drop a Saved View the Reference Attachment Settings dialog will automatically set the Nested Attachments to Live Nesting with a Depth of 99.

Exercise 4: Place Section Callout on the standard Saved View on Plane View model of Exercise‐3 Drawing Composition.dgn file.



1 Continuing with the Drawing Composition.dgn file, open the Annotate Task and click on the Place Section Callout tool (T + 1).

2 In the Place Section Callout tool settings, enter the following settings:

Detailing Style: Detailing Symbol

Annotation Scale Lock: Enabled

Create Section View, Name: Section 1

3 Follow prompts and place a horizontal section through the Exercise‐2 Plan View then click in View to have Section Callout display.



4 If you want to change direction of the section, (Green Arrow), right click on arrow and then click on Flip Direction.

Exercise 5: Place a view of the Section Callout in the existing DGN file.

1 Continuing with the Drawing Composition.dgn file Right click on the Section 1 Callout, and select the Place View option. Follow the prompts and place the view below the Plan View.

2 Click on Element Selection tool and select Section 1 Callout. Change the extents of the section by moving the blue bolt handles. Right Click on the



green arrow and Flip Direction of the callout. The new placed view will update to reflect the new extents.



3 To change the presentation of the new placed view, open the References dialog, select the placed view and Set the Reference Presentation.

Exercise 5: Place additional callouts and associated views.

1 Continuing with the Exercise‐3 Drawing Composition.dgn file, open the Sheet Composition Task and create a new sheet model named Details.

2 Open View 1 and View 2 and select Window > Tile.

3 Make View 1 the Active View by clicking on the Window header.

4 Open the View Attributes dialog and set the following:



Models: Plan View

5 Make View 2 the Active View by clicking on the Window header.

6 Open the View Attributes dialog and set the following:

Models: Details

7 From the Annotation Task select the Place Detail Callout (T + 2) and enter the following tool settings:

Detailing Style: Detailing Symbol

Name: Detail 1



8 Follow prompts and place Detail Symbol as indicated below.

9 Create other Detail Callouts in View 1, place them in View 2 then modify their scale, position, extents and Reference Presentation.

Note: When the Saved Views are placed in models that reside within the same DGN file, each view can display a different model. This enables you to test and see the Dynamic capability with the Dynamic View Workflow.

2D or 3D sheets

Normally, you should use 2D sheet models. You can reference your 3D models into a 2D sheet model. This ensures that all dimensioning is 2D.

Even when True dimensioning is used, it still only considers the planar dimensions (x and y axes) and no allowance is made for geometry that slopes into or out of the view (z axis).

Take, for example, a case when you dimension the projected distances, such as the height of a roof above the eave line. In a 2D sheet you can do this on a 3D reference without concern that the dimension may be taken along the slope of the roof back into the view.


Module Review

If you intend to dimension in an Isometric view in a sheet, then a 3D Sheet model would be required. In these cases, True dimensions will take into account the depth of the view.

Module Review


Questions

1 Name the steps in the drawing composition workflow.

2 Define a design.

3 Define design composition.

4 Define sheet composition.

Answers

1 Organize the project data, design composition, view composition, sheet composition.

2 A collection of elements in a design model that are drawn at full scale (1:1). A design is not intended to be a finished drawing for publication. A design encapsulates part of a project for active editing and uses references for backgrounds only.

3 A collection of references at full scale (1:1) intended for use in several designs, design compositions, or sheet compositions. A design composition differs from a design in that it is composed predominately of references.

4 A collection of references and elements in a sheet model that define a finished drawing sheet, ready for publication.


Importing and Exporting Drawings in 3D

Module Overview

While working in 3D is an efficient way to design, you may still need to produce 2D versions of your work. You can create designs with 3D geometry, and then let MicroStation produce 2D views and sections from the 3D geometry.

Typically, designing is performed in Design models and drawing sheets are created, or composed, in Sheet models.

You will see methods of importing and exporting 3D data, since there are times when you need to exchange design file data between 2D and 3D models. You can reference 2D models to 3D and vice‐versa. Alternatively, you can export a 2D model to a 3D model, creating a new file with the 2D elements in a 3D model.

To put 3D elements into a 2D model you must first flatten them to 2D elements. This can be done by exporting the 3D elements to a 2D model. To create a drawing of a 3D model, with or without hidden lines displayed, you can export to a Visible Edges DGN file.


• Basic knowledge of 3D modeling

• Knowledge of MicroStation references

Module Objectives


• Create 2D sheets from 3D design models

• Import and Export 2D and 3D data

Feb-09 537 Importing and Exporting Drawings in 3D





Questions

1 When using Design or Sheet models, what is typically the best use for each?

2 What do the Hidden Line or Filled Hidden Line Display Modes produce?

Answers

1 Typically, designing is performed in Design models and drawing sheets are created, or composed, in Sheet models.

2 They generates a surface model in which each visible surface is filled with the element color.

Exporting 3D to 2D

To export a 3D design file to a 2D design file, select File > Export > 2D. During this process you reduce all the z‐ values for elements to one z‐ value, effectively flattening the design.

Flattening a 3D design in this fashion reduces all the vertical elements in a view to zero. Only those elements with a horizontal component, in the view selected for export, will appear in the exported 2D file.

Conversion options

The options in the Save 3D as 2D dialog control the conversion options.

• View: Sets the view that determines the orientation of the design plane upon which 3D elements are projected. This determines whether you want to project all of the information in one of the x‐, y‐, or z‐ axes on to one xy‐, xz‐ or

Importing and Exporting Drawings in 3D 538 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Exporting 3D to 2D

yz‐ plane. That gives you flexibility as you can reduce all the z‐depth data in the Top view for plan drawings or the y‐depth data in the Front view for front elevation drawings.

• Preserve Z Range: If on, the 3D Z range data is stored in the generated 2D elements. This data then can be used if the elements are converted back to a 3D design file.

• Ignore View Rotation: If on, the view rotation is ignored and the 3D file is saved as in a Top view. This setting preserves the X‐Y geometry coordinates and discards the Z information.

While this form of conversion from 3D to 2D has its uses, a more practical option for producing drawing style 2D files is Export Visible Edges. With this option, you can have the hidden lines removed, or displayed in a different line style and/or placed on a different level.

Exporting Visible Edges

With this process you can create visible edge views that can be stored in the active DGN file or exported to an external DGN file.

Feb-09 539 Importing and Exporting Drawings in 3DCopyright © 2009 Bentley Systems, Incorporated

Exporting 3D to 2D

When you select File > Export > Visible Edges, the Export Visible Edges dialog appears.

In this dialog are numerous options grouped on tabs, General, Symbology and Advanced.

General

• View ‐ Sets the view that determines the orientation of the visible edges.

• Boundary ‐ Sets the boundary of the exported visible edges design file. If Tiling is enabled, then the boundary setting is disabled and the entire DGN file is exported.

Design File ‐ Entire design file is exported.

View — view contents are exported.

Fence — existing fence contents are exported (not available if there is no fence).

• Method ‐ Sets type of Visible Edge extraction to do.

MicroStation ‐ This setting should be used where the model is a mixture of solids and standard geometry.

Parasolids — This method is recommended when working with solids models. It is more accurate, can be slower for larger files, and does not support computing intersections between elements.

• Calculate Intersections ‐ If on, intersections between elements are calculated automatically in the visible edges design file, which can significantly increase the processing time.

• Include Hidden Edges ‐ If on, hidden edges are drawn. The Symbology tab has controls to set the Level, Color, Line Style, and Line Weight of the hidden edges.

• Facet All Surfaces ‐ If on, all surfaces are converted to facetted surfaces in the visible edges output.


Exporting 3D to 2D

• Remove Smooth Edges ‐ If on, blended (smooth) edges of 2 tangent surfaces are not displayed.

• Rule Lines ‐ If on, rule lines are drawn on curved surfaces to better display the shapes of the surfaces.

• Expand Custom Line Styles ‐ If on, Line Style attributes are processed and appear in the generated visible edges. If off, Line Style Attributes are ignored. When Custom Line Styles are processed, they appear in the resulting visible edges file as stick geometry. That is, they are represented by standard elements and no longer have custom line style attributes.

• Expand Hatch ‐ If on, any hatching present in the source view/file/fence is processed and appears in the generated visible edges. If off, hatching present in the source view is ignored. When hatching is processed, it appears in the resulting visible edges file as “stick geometry”. That is, it represented by standard elements and no longer has the hatching attributes.

• Process Text and Dimensions ‐ If off, text and dimensions display without any test for visibility; they show independently of the depth in view.

Symbology

Controls symbology of output data.

Advanced

• Accuracy ‐ Controls the precision to which hidden line removal processing performs internal calculations. In general, most calculations are exact (accurate). In some cases, however, it is faster to produce approximate results.

• Low, Medium, High — If the options Low, Medium or High are selected, the accuracy is computed accordingly, based on the size of the view to be processed. Selecting High Accuracy will produce higher quality output at the expense of increased processing time.

• To Tolerance — When the To Tolerance setting is chose, the accuracy of the processing is controlled by the Tolerance setting. Tolerance controls the maximum error (the precision) for the hidden line removal calculations explicitly; the accuracy is therefore not dependent on the size of the view. Lower tolerance values will also produce higher quality output at the expense of increased processing time.


Exporting 3D to 2D

Exercise: Create a visible edges file


Project: Plant

2 Open BSI700‐S0501‐UnloadingPlatform.dgn.

3 Select File > Export > Visible Edges and, on the General tab, set the following:

View: 1

Boundary: View

Method: MicroStation

Export To: 2D File

Automatically open output file: Enabled

Include Hidden Edges: Enabled

4 On the Symbology tab, set the following for the Hidden Edge Overrides:

Color: Enabled and set to 4

Style: Enabled and set to medium dash (2)

Weight: Enabled and set to 0

5 In the Export Visible Edges dialog, click the Preview button.

The Export Visible Edges Preview window opens to show a preview of the visible edges file, with symbology as defined.

6 Click Export.


Exporting 2D to 3D

The Save Visible Edges Design File As dialog opens. By default it has given the proposed file the same name as the active design but with a .hln extension (for hidden line).

7 Click Save.


The file is processed. On completion, the active file is closed and the visible edges file is opened because you enabled Automatically open output file.

When you create a visible edges file, it creates a new DGN file. You can add visible edges views to an existing DGN file using the Export Visible Edges process using the Active File option.

Exporting 2D to 3D

In 2D you work on a design plane that is like a sheet of paper. This plane is defined by x‐ and y‐ coordinates. In 3D the z‐ coordinate is added. When converting from 2D to 3D, the geometry in the model does not really change. It will be flat, unless elements contain Z range data from previous conversions from a 3D model. Once converted to a 3D DGN file, however, you can use those elements to produce 3D solids using the 3D construction tools, such as Extrude and Construct Revolution.

Let’s review the settings associated with exporting a 2D model to 3D.

Conversion Options — control the source and the orientation:

• View Orientation — sets the view in the 3D DGN file into which the 2D model elements are placed. This can be any one of the standard views, such as Top,


Export to and from Google Earth

Front or Left. In other words, you must decide whether your 2D model file is to be used as a Top/Bottom, Front/Back or a Right/Left view.

• Z Depth — Each converted element is placed at a depth in the Top view that can be the same or vary from element to element.

To specify a fixed depth, select Fixed from the Z Depth option menu and enter the depth, in working units, in the Value field. The default depth is 0:0 – or zero working units in z‐.

The following Z Depth options are useful only where elements previously were converted to 2D with Preserve Z Range on.

• Contour Z Low or Contour Z High — fixes the depth for all elements at the design file’s lower or upper Z contour (elevation) limit. This means all elements are brought to the elevation of either the upper or lower z‐ contour (elevation).

• Element Z Low or Element Z High — places each converted element at the depth that equals its lower or upper Z range limit. These limits equal the bottom and top of the design cube so essentially you are putting all the elements at the top or bottom of the design cube.

• 2D Z Range/Z Low or 2D Z Range/Z High — places each converted element at the depth that equals its maintained 2D Z range lower or upper limit.


The Google Earth environment provides you with an interface to planet Earth.

What Google Earth is

You can view and navigate 2D and 3D models of projects in the context of the Google Earth environment. Through this connection, MicroStation users can publish DGN and DWG models which can be viewed and navigated in the context of the geographic imagery with associated content.

MicroStation files placed in the Google Earth environment can contain links to more detailed data that can be reviewed locally, turning the Google Earth environment into a graphical delivery system for project information. This information can be provided in a variety of formats, including Excel spreadsheets,



Word and PDF documents, additional DGN and DWG files, and URLs. All types of project information can be shared through the Google Earth interface.

How it works

You export geometric data so that it can be viewed in the context of satellite data, aerial photography, maps and other geographical data. You then get an aerial view of geometry and geography. However, the Google Earth environment is not intended to be a detailed CAD viewer.

While the Google Earth environment is designed and optimized for spatially large designs, it is not intended for visualizing geometric detail. Including excessive detail will quickly exceed the current capacity. It is important to select and export only the geometry that is valuable.

MicroStation provides data to the Google Earth application as KML documents, an XML based data structure for creating and sharing geographic data. MicroStation geometry exported to KML retains the reference and level structure that is defined for a model. This lets you selectively control the display of individual levels or references. Saved views are also saved to KML so that they can be used to navigate to views of interest.

The general procedure is as follows.

1. Go into the Google Earth environment and create a KMZ file for the location of interest.

2. Go to MicroStation and place a monument point cell at the location specified in Google Earth environment. This action will reference the KMZ file created in step 1.

3. Define True North in MicroStation, or use other geo‐coordination techniques.

4. Publish to the Google Earth environment from MicroStation.

For users that use structure‐centric coordinate systems, selecting a standard GCS from the Library is not possible. Instead, given some information about geographic positioning of your model, MicroStation can calculate an Azimuthal Equal Area GCS that will allow you to realize all the benefits of Geo‐Coordination. You tell MicroStation about the geographic positioning of your design using Geographic Placemarks. A Placemark is a cell that contains text fields labeled Name:, Longitude:, Latitude:, and Altitude:. The longitude, latitude, and altitude fields specify the geographic position relative to the WGS 84 datum, which is the



datum reported by GPS devices and also used by Google Earth. The corresponding position in the design file is specified by placement point of the cell. The scale and rotation of the cell does not affect its meaning as a Geographic Placemark.

Google Earth tools

The Google Earth tools are found from Tools > Geographic

Tools from left to right are a follows:

• Export KML file

• Capture Google Earth View

• Define Google Earth Placemark Monument

• Synchronize Google Earth View

• Follow Google Earth View

• Google Earth Settings

• Play Camera Animation in Google Earth

Defining geographic location

In order to accurately define the geographic location of a model when exporting, you must provide the model’s location and its orientation. There are 3 methods you can use to do this.

• Use the MicroStation GeoExtension applications and their associated projection capabilities to handle geographic projections.

• Use a single placemark monument to define the location of a known point in the model and then use the DEFINE NORTH key‐in to indicate the orientation. In order to use this method, the geometry must be drawn accurately and the working units must be set correctly so that the size of the geometry is known.

• Place 2 or more placemark monuments to provide the complete projection transform (location, orientation, and scale).

This method is useful when accurate scale and orientation information is not known and an approximate projection is sufficient.



Defining a placemark monument

These are used to associate a geographical location from a Google Earth environment placemark file to a monument point in a model. First you must create a placemark file in the Google Earth application and save it as a KML file.

To create a KML file in Google Earth:

1. Launch the Google Earth application.

2. Create a placemark at the desired location, using Add > Placemark.

3. Use the corner of a building or a parking lot your placemark. That way you can snap to the element when you place a monument cell in MicroStation.

4. Right click on the placemark and select Save As from the pop‐up menu.

5. Save the file as Type .kml or .kmz.

6. Click Save.

Placemark monuments are cells named KmlPlacemark with enter‐data fields that show the name, longitude, latitude and altitude of the monument. The placemark cell is located in the cell library KmlPlacemark.cel in the \System\cell folder. It is placed automatically when you use the Define Google Earth Placemark Monument tool.

The origin of the cell represents the location of the placemark in the model. The design file location can be modified by moving the cells. The longitude, latitude, and altitude values can be modified by editing the appropriate text elements. Placemark cell geometry is placed on the level KML Placemark. You can turn this level off to avoid displaying or exporting the monument geometry. Scale is set by the active design file scale.



Exercise: Define a placemark monument


Project: General

2 Open Import‐Export.dgn.

3 Open the model Google Earth.

4 Select Tools > Google Earth.

There are 2 existing placemarks in this drawing but you will add another. See if you can find the other placemark cells.

5 Select Define Google Earth Placemark Monument.

6 Snap to the location shown to identify the point at which you want to locate the monument and enter a data point to accept.

7 In the Select Monument Placemark File dialog, navigate to the class data set folder. Select Google Earth ‐ Bentley Exton.kml.

8 Click Open.

9 Type the following in the Key‐in browser:

DEFINE NORTH BYPOINTS

10 Press Enter.

Snap h



11 Enter a data point at the placemark location and a second in the +y direction, or to the top of the screen/view.

This defines true North.

Note: If you are working with MicroStation GeoGraphics Extension, you do not need to define a monument point in a model.

Removing placemark monuments

To remove all placemark monument cells in a model, you can use the key‐in GOOGLEEARTH PLACEMARK DELETE.

Adding Hyperlinks

You can add a variety of hyperlinks to web pages and other data sources using MicroStation Engineering Links tools.

• Show Engineering Links



• Attach Engineering Link

• Edit Engineering Link

• Follow Engineering Link

• Connect to Browser

• Delete Engineering Link

Supported HTML protocols are http://<web address>, mailto:<email address>, file:///<path>, and ftp://<web address>.

You can also place a XML link. If you are creating a simple XML link, you can specify parameters which further define how the link should operate.

• Role ‐ Specifies what role the object of the link will specify, for example, that of a reference or cell library.

• Show ‐ Determines whether any existing page should be replaced or if a new browser should be opened.

Hint: Remember Engineering Links are stored as tags.

If you have Internet access and the Google Earth application is installed, you can complete the following exercise.

Exercise: Adding links

1 Continuing in Import‐Export.dgn, in the model Google Earth, select Tools > Engineering Links.

2 Click Attach Link with the following tool settings:

Link Type: HTML

URL: http://www.bentley.com

Leave others settings to Default.



3 Click on a building’s roof element.

4 Enter a data point, away from any elements, to accept.

5 Add additional links to elements.

Exporting files

Once you have created a placemark file and defined a placemark monument in a model, you can export the design geometry. When exporting, you have the choice of file types.

The KMZ file type is a compressed version of KML. Both file types are recognized and extracted automatically. Typically, KML documents are large, so the compressed (KMZ) form is preferable.

You can export to:

• SketchUp SKP format to place MicroStation generated geometry into SketchUp or the Google Warehouse.

• Collada files (*.DAE) include support for textures, and can be used in other applications that support them. You can export geometry to Collada (version 1.4) files, by selecting File > Export > Collada.



Configuration

You can control the default directory for the output KML files by setting the configuration variable MS_KMLOUT. If this variable is not set, the output directory defaults to the current DGN file location.

Settings

When geometry is exported, the view attributes and level settings are taken from the active view. It is important to set up the view exactly as you want it to display in the Google Earth application. Output should be minimized to include only necessary data by turning off unnecessary levels and disabling text and dimension view attributes if they are to be excluded.

The Google Earth Export Settings dialog has settings that control how the geometry is exported. Open it by clicking the Google Earth Settings tool.

General

• Google Earth Version ‐ Lets you set the version of Google Earth required, 3 or 4. Google Earth version 4 introduced support for textures. Select this version if you want to export geometry with textures intact.

• Stroke Tolerance (Meters) ‐ Controls the accuracy of the mesh approximating curves or curved surfaces. A smaller value produces a more accurate representation but file size is larger and display is slower.

• Transparency Override ‐ Controls the level of transparency for all the geometry. Including a level of transparency allows the geometry to be seen without obscuring the aerial photography below it.



• Convert Custom Line Styles ‐ Converts custom line styles to KML by dropping them to their individual components. This produces correct display of the line style but can increase file size and degrade performance.

• Convert Raster References To Ground Overlays ‐ Converts raster references in the X‐Y plane to ground overlays. The raster reference overlays are placed in a separate Raster References folder. Their display can be controlled as a group by selecting the folder, or individually by selecting the individual references.

• Include Raster References in KMZ File ‐ Includes raster references if you are creating a compressed KMZ output file.

• Open File after Export ‐ Opens the KMZ in Google Earth upon completion.

3D

• Render Mode ‐ Sets the mode of shading. If a view is rendered and this is set to From View, then the display mode is taken from the active view.

• Altitude Mode (3D only) ‐ Controls the interpretation of altitude values in Google Earth, which has 2 ways of rendering the Earth´s surface.

If the Google Earth Terrain setting is disabled then variations in altitude, such as mountains and valleys, are ignored. In this case, the Earth is depicted as a perfect sphere (ellipsoid). In Google Earth: Left Frame > Layers > Primary Database > Terrain.

If the Terrain setting is enabled then the variations in altitude in are depicted in the Google Earth display.

• Altitude Mode (3D only) ‐ This setting applies only to 3D models. For 2D models, the Flatten To Ground option is always used.

Relative To Ground — Altitude value is interpreted as a distance from the ground plane. In this mode, geometry with a positive value is always displayed. As the altitude is interpreted as a distance from the ground, this can produce distortion in the display of geometry when the Terrain setting is enabled and there are significant changes in altitude.

Absolute — All altitude values are interpreted relative to sea level.

Flatten To Ground — All altitude values are interpreted as being at ground level. This setting is useful for any data that is truly 2D. For 3D geometry this has the effect of flattening the geometry and is usually not desirable.

• Altitude Bias (Meters) ‐ Google Earth is based on the physical representation of the Earth with coordinates specified by longitude, latitude, and altitude. Geometry with negative altitude values typically are not displayed (obscured by the Earth´s surface). The Altitude Bias setting specifies a value that is added



to each coordinate in a KML file. A positive value will move geometry up from ground level, while a negative value will move geometry toward the ground.

• Convert Wireframe Geometry in Rendered Views ‐ Exports wireframe geometry, such as text, lines, curves, and dimensions along with shaded objects in a rendered view.

Captured Geometry

These settings let you set the level of detail that is captured as well as the following:

• Capture As ‐ Option menu that sets how the Google Earth terrain is captured.

Mesh ‐ Terrain is captured as a mesh.

B‐spline Surface ‐ Terrain is captured as a B‐spline surface.

• Capture Detail ‐ Option menu that lets you set the level of detail for captured Google Earth images.

Low

Medium

High

Very High

• Use Google Earth View to Determine Rotation ‐ The Google Earth view perspective is maintained on capture. Where there is no information about the location of a model, it is assumed that your model’s origin coincides with the center of the Google Earth view and that the y‐axis is to be aligned with North.

Export process

When you export models, first use the Google Earth Settings dialog to define how they are exported and displayed. When you export, the Google Earth application opens automatically if is not already open. It navigates to the location of your placemark and model.

Exercise: Export geometry

1 Continuing in Import‐Export.dgn, in the model Google Earth, click Export Google Earth (KML) File.

2 In the Create Google Earth (KML) File dialog, leave the file type at KMZ.

3 Click Save.



The export is completed and the Google Earth application opens and navigates to the location. The geometry is displayed against the imagery.

Capture Google Earth Image

Use this tool in 3D DGN files to capture the terrain and imagery of the current Google Earth view. The captured image will be at screen resolution and in monochrome (a Google Earth restriction).

Model location

If there is no information about the location of the model, MicroStation assumes that your model´s origin coincides with the center of your Google Earth view and that your model´s y‐axis is to be aligned with north. If location information is present in the model, then MicroStation uses the transform derived from it.

Hint: To maintain your Google Earth view perspective, enable the Use Google Earth View to Determine Rotation option in the Google Earth Tools Settings dialog.

How to capture a Google Earth image:

1. Set up a Google Earth view displaying the required area.

2. In MicroStation, select the Capture Google Earth Image tool.

3, Enter a data point to capture the current Google Earth view.

Note: The use of the Google Earth images is restricted by the Google Earth license agreement. Please consult that document (select Help > License) to insure that your use of these images does not violate the restrictions.

Tips for capturing a view

Helpful settings and options within the Google Earth application are as follows:

• For best results, the view should have the camera pointing straight down.

• Google Earth application’s camera tilt control

• In order to capture terrain, the Terrain layer must be enabled in the Layer panel.

• On the View tab of the Tools > Options, Google Earth Options dialog, set Detail Area to Large 1024 x 1024 and Graphics Mode to DirectX.

• Resize the Google Earth application window to the size of the graphics image desired.



Synchronizing Views

You can move to the same view location and orientation in either MicroStation or the Google Earth application.

Synchronize Google Earth View tool

Use this tool to navigate the Google Earth application to the location and orientation of the active view in MicroStation.

As the Google Earth application supports a camera model with a fixed lens length and restricts the camera to pointing downward only, the views will not always match exactly, but should provide a relatively good approximation for most views.

To synchronize, set up the view as desired and select the Synchronize Google Earth View tool. If the Google Earth Application is not open, it opens automatically.

Follow Google Earth View tool

Use this tool to navigate the active view in MicroStation to the location and orientation of the current view in the Google Earth application. This tool will work only if the model’s view location is geographically close to the current location in the Google Earth application.

To match the active view to the Google Earth application’s view, set the view up as desired and select the Follow Google Earth View tool.

Control in Google Earth

In the Google Earth application you can control the display of MicroStation data.

How to control the display of MicroStation data:

In the Google Earth environment, examine the left frame. On the left, under the section Places > My Places > Temporary Places > Import‐Export, you will have access to Levels, Raster References, Reference Files, Links, and Saved Views. Use these controls to alter your Google Earth display.



3D Warehouse

MicroStation's 3D Warehouse interface lets you open and place SketchUp models in your designs. Through this interface you can directly access the growing collection of 3D models available from the Google 3D Warehouse, or you can upload your models to 3D Warehouse in SketchUp format.

Access to these features is from the Utilities > 3D Warehouse sub‐menu, which gives you the following functions in MicroStation.

• Open — a SketchUp model, in read‐only mode, from 3D Warehouse.

• Place As Cell — a SketchUp model from 3D Warehouse.

• Place As Model — a SketchUp model from 3D Warehouse.

• Share Model — to upload your models as SketchUp files to 3D Warehouse

Working Offline

The Google Earth cache is stored in the folder:

C:\Documents and Settings\<user>\Local Settings\Application Data\Google\Google Desktop Search\

Play Camera Animation in Google Earth

This tool allows a user to play a MicroStation camera animation in Google Earth. It does not allow one to play or export any other kind of animation to Google Earth. To use this tool, do the following.

How to play a MicroStation camera animation in Google Earth:

1. Open up a 3D DGN file with a Camera Animation loaded. Refer to Animation.dgn for more information.

2. Open Google Earth.

3. Activate the “Google Earth Play” tool. The camera animation will play in Google Earth. You can pause the animation by right clicking in your MicroStation view and restart it by left‐clicking.


Creating PDF Output with 3D Content

Notes about this tool:

In order to create your own camera animation, simply follow the normal procedures outlined in MicroStation’s help file. The only extra step needed to play your animation in Google Earth is to geo‐locate your file in some way. You do not need to export any geometry from MicroStation to Google Earth for this feature to work.

Certain views such as those that have the camera too close to the ground or not pointed down enough are problematic in Google Earth. If you find that your animation is jumpy, this is most likely the issue.

This tool combined with the Google Earth Pro Movie Maker module can be used to create effective presentation aids.

Optional Exercise

1 Open the model Extra Google Earth.

2 Reference the end of the bridge to the following coordinates:

Latitude: 25°22'19.32"N

Longitude: 51°31'57.18"E


In Acrobat 7.0, Adobe Systems added the ability to include 3D geometry within their PDF format. The 3D portions of a PDF file are referred to as 3D annotations. With Acrobat 7.0 Reader, it is possible to view, navigate and interact with the 3D Annotations.

Typically, PDF documents printed from MicroStation contain 3D annotations that encapsulate everything required to visualize a design. This includes model geometry, materials, lighting, and texture maps. 3D annotations also can contain animations, both of the model geometry and of fly through animations of the viewing camera.

In addition, you can integrate 3D annotations into existing documents, and instructions for adding links and book marks to let the user interactively control the viewing of the 3D content.



Integrating 3D PDF Annotations into PDF documents

MicroStation’s 3D printing produces either separate PDF documents with a 3D annotation in each, or (with batch printing) a multi‐page PDF document with separate 3D annotations on each page. While these can be useful in their own right, the real power of 3D annotations within PDF is in their ability to include them within an existing PDF document such as a marketing brochure, a design portfolio, or a technical manual. Essentially, there are 2 methods for doing this – both of which require Adobe Acrobat Professional 7.0 or better.

With the Universal 3D (U3D) method, you do the following.

1 Export U3D files from MicroStation.

2 Insert the U3D files into the PDF document with the 3D Tool in Acrobat Professional (select Tools > Advanced Editing > 3D Tool).

When MicroStation generates a U3D file, it also generates a JavaScript file with the same name but the “.js” extension. This file contains additional information and JavaScript code that enhance the behavior of the 3D Annotation within Acrobat. It includes code to control animations and additional tools to control geometry display.

The primary disadvantage of using the U3D method for creating 3D annotations is that Acrobat Professional does not extract the initial and saved view information from the U3D file. These views, however, do exist within the U3D file, so it is possible that this limitation will be addressed in a future version of Acrobat Professional. At this time, it is probably preferable to use PDF to contain the 3D geometry (and views) as described in Method 2 (below). If the U3D method is used, it is necessary to use the Acrobat navigational tools to recreate the initial view and any saved views that are required.

With the Inserting PDF Pages with 3D Annotations method, you do the following.

1 Create PDF pages, with 3D content, from MicroStation.

2 Insert the MicroStation PDF pages into the document with Acrobat Professional (select Documents > Insert Pages).

This is the preferred method as it preserves, within the PDF document, all of the content that MicroStation generates, including the initial view and the saved views. Once the page is inserted in the document, the Acrobat Professional editing tools can be used to add additional text, images, etc., onto the page containing the 3D annotation. These tools are somewhat limited, so this method also is somewhat awkward, but in most cases it works well.



For instances where there is a good deal of complex existing content on the page to contain the 3D annotation, or more than one 3D annotation exists on a single page, it may be preferable to use Method 1 (U3D) and recreate the view information.

Adding links and bookmarks

Bookmarks and Links are valuable navigation aids within 2D documents. They are also extremely useful in documents with 3D annotations as they can provide familiar controls to a user who may be encountering 3D data for the first time. Acrobat Professional provides tools for connecting bookmarks and links to 3D views, and to user defined JavaScripts.

The process of connecting a Link or Bookmark to a 3D view is straightforward and described in the Acrobat Professional help file.

Using JavaScript to control 3D annotations

JavaScript is the programming language provided by Adobe for advanced scripting within PDF files. By selecting the Run a JavaScript entry for the action, for either a link or bookmark, a JavaScript is run whenever the link or bookmark is selected. A complete description of JavaScript and the 3D interface in particular is available from Adobe. Details on how to do some rudimentary scripting to control the 3D annotations generated by MicroStation are included below:

In general, in order to control a 3D annotation it is necessary to get the 3D annotation object. The 3D annotations for a given page number are available through the global function getAnnots3D (see the Adobe JavaScript Scripting Reference for additional details). When MicroStation generates the JavaScript for a 3D annotation, it adds several functions to the context3D member to allow convenient control of the annotation.

Creating a 3D PDF

New features have been added to MicroStation V8 XM Edition's U3D functionality. New features include:

• Support for clip volumes, clip masks, and reference clip boundaries

• Support for raster references



• Mesh Tolerance

• Support for Engineering Links

• Publish reference and level structure to model tree

• Global lighting settings

In order to take advantage of these new features Adobe Reader or Adobe Acrobat 7.07 is required.

In this exercise you will be using the Print dialog. This same capability of publishing PDF files with 3D content is available in MicroStation PDF Composer.

On‐Line Help Topics: MicroStation > Working With Complete Designs > Printing > Printing Basics > 3D Content in PDF Files and What's New? > 3D Content in PDF Files

In this exercise you will be using MicroStation's Print dialog to create a PDF that includes 3D data. New U3D features that will be covered are Engineering Links, raster references, and reference and level structure in the model tree.

Exercise: MicroStation Printing and 3D PDF

1 Continuing in Import‐Export.dgn, in the Google Earth model, select Utilities > Saved Views.

2 Apply the Thomas P. Bentley Building Parking Lot view to View 1.

3 Select Tools > Engineering Links.

4 Select Edit Engineering Links.



5 Place the pointer over 1 of the columns on the front entrance to the building, click it and accept to show the link in the Edit dialog.

This shape has an Engineering Link to the http://www.bentley.com web page. This link along with others in the file will be included in the U3D model in the exported PDF file.

6 Select File > Print to open the Print dialog.

7 Select File > Select Windows Printer, and select pdf.pltcfg.

8 Select the ANSI B Paper Size.

9 Select Tools > Maximize and maximize the plot to the B size form.

10 In the Print dialog, select Plot to 3D.



11 In the Print dialog, select Settings > 3D Plotting to open the 3D Plotting Options.

12 Set the Lighting Mode to Day, and then click OK.

13 Select File > Print.

14 Select the directory C:\ as the output directory, and leave the file name as Import‐Export‐Google Earth‐000.pdf.

15 Click Save.

In the next exercise, you will view the PDF document you just published that included the Google Earth 3D model. Adobe Acrobat 7.07 or later is required to view the new 3D PDF features.

Exercise: View a 3D model in Adobe Acrobat

1 Open C:\Import‐Export.pdf in Adobe Acrobat.

Note: The saved views, raster data that was in the 3D model as well as the Engineering Links were included with the U3D model in the PDF.



2 Click Views option menu on the 3D tool bar and select the Thomas P. Bentley Building Parking Lot view.

3 Place the pointer over the front entrance to the building.

It highlights, indicating that there is a link on the element.

4 Right click on the front entrance and select Follow Link from the pop‐up menu.

5 Select the Model Tree tab on the left side.



This shows you the levels and references associated with the 3D model.

Click on the Level Building Roof in the top Model Tree frame to turn it off. Click it again to turn it back on.

The middle frame in the Model Tree is the view control. Here you see the saved views for the model.


Module Review

6 Click on different views and then click the Default View button to return to the default view for the model.

7 Navigate the view using the rotate, pan and zoom commands.

8 Save the view by clicking Create View in the view control area

A view called NewView6 is placed in the list.

9 Click on it and rename it MyView.

10 Navigate to another view and then select MyView.

11 Right click on MyView in the ModelTree and select Delete View.

12 Exit Acrobat.

Module Review


Questions

1 When creating sheets for printing, you have options regarding assembly. What are they?

2 In the event that you need to change the scale of a drawing, how can you quickly change the size of all text?

3 Which configuration variable can you set to ensure associated dimensions remain associated?

4 When you export a 3D design file to a 2D design file, what happens to elements during the process?


Module Review

Answers

1 Reference the geometry at full‐scale, scaling the border reference up to fit the geometry. Print at the required scale.

Reference the border at full‐scale, scaling the geometry down to fit the border. Print at full‐scale.

2 By changing the Annotation Scale setting for the model.

3 Create MS_HLINEMAINTAINASSOC with a value of 1.

4 It reduces all the z‐ values for elements to one z‐ value, effectively flattening the design.


Course Summary

Course Summary

Now you will be able to:

• Use 3D view controls to see what you need when you need to

• Use 2D tools in 3D models

• Apply AccuDraw in 3D

• Use 3D primitive solids for basic forms and design

• Modify and do basic analysis of solids

• Create and modify B‐spline surfaces

• Create parametric feature models

• Use advanced feature modeling techniques to increase 3D efficiency

• Apply conceptual modeling tools for push/pull modeling

• Use mesh modeling for site design and soil modeling

• Apply drawing composition tools to create 2D production drawings

• Use the rendering and animation tools to make your 3D model photo‐realistic

Feb-09 569 Course Summary


Course Review

Course Review

Now that you have completed this course, let’s measure what you have learned.

Questions

1 In 2D models, you work on a design plane. What is the working area in 3D?

2 What is the Active Depth?

3 How can you to move focus to the AccuDraw window?




7 What happens if you increase the size of the solids modeling area?

8 Where can you change the SmartSolid display mode?

9 What do the U and V directions represent, respectively?

10 What methods can you use to select faces, or any element, that's hidden?


12 Name 3 ways to create meshes.

13 If a section element is in an opposing direction, how you can reverse its direction?

14 What are Surface Normals?


16 What is a Local variable?

17 True or False: You can specify that the materials for a DGN file be stored within the file itself.

18 Name three global lighting types that can be used in rendered images.

19 When creating sheets for printing, you have options regarding assembly. What are they?

Course Summary 570 Feb-09Copyright © 2009 Bentley Systems, Incorporated

Course Review

Answers

1 In 3D models, the 2D design plane becomes a 3D cube, known as the design cube. All geometry is drawn in this design cube. Locations in the cube are defined by x‐, ‐y and z‐ coordinates.

2 The Active Depth is a plane, parallel to the view or screen, which is always located within the Display Depth of a view. The Active Depth of a view determines where data points fall by default. If you enter a data point in a 3D view, without snapping to an existing element, it falls on the Active Depth plane.





7 It will reduce the available precision.

8 The Display Mode setting in the B‐spline and 3D dialog.

9 Rows and columns.

10 Highlight the nearest face or element, and the reset until you select hidden face. Rotate the view or use another view.

11 Sometimes called a control net, the control polygon determines shape.

12 By Element or Shape, by Contours, by Points.

13 With the Change Element Direction tool or by using the Surface by Section tool and a Ctrl data point on the element.

14 Indicators that are generated every time you create a surface.

15 You can modify them using the parameters used to create them, or you can modify them interactively, similar to 2D elements.

16 It is a variable that is created by MicroStation automatically, for all feature parameters of a solid, and available for that solid (only).

17 Reference the geometry at full‐scale, scaling the border reference up to fit the geometry. Print at the required scale.

18 Reference the border at full‐scale, scaling the geometry down to fit the border. Print at full‐scale.

19 True. Rather than using an external.pal file.

Feb-09 571 Course SummaryCopyright © 2009 Bentley Systems, Incorporated

Micro Station V8i Everything 3D

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