Image courtesy of:Ryder Architecture Limited

Building Information Modeling

Families and Parameters

Slides are made based on Autodesk BIM Curriculum, Greenwold, S., and D. Driver. (2007), Building Information Modeling with Revit Architecture: Lecture Notes, Autodesk, Inc., with additional content created by Wei Yan, Texas A&M University.

Working with Compound and Vertically Compound WallsVertically Compound Walls (Stacked Walls)

A wall with non-uniform structure throughout its height is known as a vertically compound wall.

You can divide the layers of a vertically compound wall into vertical parts. Each part can be composed of a different material.

1. Protruding ledge at the top of the block

2. Three rows of brick inset from the main face of the wall

3. Row of brick standing vertically

4. Cap

More on Compound Structure:

http://help.autodesk.com/view/RVT/2015/ENU/?guid=GUID-08E47F82-BFA1-4CAB-B2EA-6C8DC9049AD8

Question:

How to create a new family with multiple types?

Question:

How to create a new family with multiple types?

Create a new family with a type and duplicate the type to multiple types.

Experiment: Creating New Types in Family

Run Revit - Load Family of Casement 3x3 with Trim, find it in Windows, edit family, add a type of 48"x48" to it, and save it to Families using a new name and new location Casement 3x3 with Trim - New.

Try to open a new project and load the saved Family Casement 3x3 with Trim – New. Examine it.

Choosing Type Versus InstanceWhy are some parameters type parameters and some instance parameters?

Type parameters are the ones that define the identity of a class of objects, and instance parameters are the ones that vary across specific individuals. Instance parameters tend to deal with context (extrinsic relationships, such as placement in a host), where type parameters tend to be intrinsic (self dimensions, for example).

The Role of the Family

If type values are stored in a type and instance values are stored in an object, what exactly is the role of the family?

The family defines what parameters exist, whether they are type or instance parameters. The family defines how the object renders itself into various views depending on its parameters.

The Role of the Family

Family A Family B

Type Parameter 1 Type Parameter 1

Type Parameter 2 Type Parameter 2

Type Parameter 3

Instance Parameter 1 Instance Parameter 1

Instance Parameter 2 Instance Parameter 2

Instance Parameter 3

The Role of the Family

It’s also about design thinking process:When architects think of doors, do they think of materials first or the geometry first? Normally geometry, for example, they draw double doors (family) on the floor plan first and then decide about its wood material (type) later.

On the other hand, when we sketch a building, we draw “instances” directly, without thinking of “families” and “types”. This shows the difference between sketching and BIM modeling.

Nested Families

A family may contain one or more other families as part of its definition. These are called nested families, and they are a powerful concept. Nested families allow aggregates of components to be treated as a single component. For example, a set of door hardware can be created as its own family and then used in many different door families. If a change is made to the door hardware, the change can be easily propagated into all the applicable door families by reloading the hardware family.

The size of the book shelf can determine the size of the drawer, or parameters can pass from a family to its nested family.

Applications of Family Types

Sample: Humanoid

• Questions?