Intro to Computer Graphics - Wk1

7/27/2019 Intro to Computer Graphics - Wk1

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BBIT 4101 COMPUTERGRAPHICS

Computer Graphics


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In this lecture,

Introductions

Course Objective

we explore what computer graphics is about Brief historical introduction

Survey some application areas

Objectives


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Intro

BIT 4101 Computer Graphics

Instructor: Jeremiah Mugambi

Email: [email protected]

Lecture: 1st Floor Room 14 (Time 5:30- 8:30 pm)

Notes: sent via email every week

Class rules: Attendance Time

Partipation, CATs and Assignments


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Prerequisites

Data Structure and Algorithms


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Reading Materials

Hearn,Baker - Computer Graphics - C Version 2ndEd


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Course Outline

Provided (Hard Copy)


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What is Computer graphic

Introduction

Fundamentals of computer graphics

Why Computer Graphics ?

History Applications


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Computer Graphics:

Computer Graphics: Computer graphics isconcerned with producing images andanimations (or sequences of images) using a

computer. This includes the hardware andsoftware systems used to make these images. Thetask of producing photo-realistic images is anextremely complex one, but this is a field that is in

great demand because of the nearly limitlessvariety of applications.


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Computer graphics deals with all aspects of creatingimages with a computer

Hardware

Software

Applications


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The Basics

Computer graphics: generating 2D images of a3D world represented in a computer.

Main tasks:

modeling: (shape) creating and representing thegeometry of objects in the 3D world

rendering: (light, perspective) generating 2D images ofthe objects

animation: (movement) describing how objects changein time


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History

The field of computer graphics has grown enormously

over the past 1020 years, and many software systems havebeen developed for generating computer graphics

of various sorts. This can include systems for producing 3-dimensional models of the scene to be drawn, the

rendering software for drawing the images, and theassociated user-interface software and hardware.


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Why Study Computer Graphics?

Graphics is cool I like to see what Im doing

I like to show people what Im doing

Graphics is interesting Involves simulation, AI, algorithms, architecture

Ill never get an Oscar for my acting

But maybe Ill get one for my CG special effects

Graphics is fun


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Applications

Everyday Use Computer Aided Design (CAD) & Industrial design Entertainment: Cinema, Games , Movie, TV special

effects, Video games

Computer Art ; Communication Training & Education Visualization: Scientific visualization , Medical visualization

Visualize complex software systems Cartography and GIS (Geographic Information Systems) Graphical User Interfaces: & everyday Use - Microsofts OS 7 & 8

use graphics Simulation & Graphics visualizations;


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Components of Computer Graphics

Rendering:

applying physically based procedures to generate

(photorealistic) images from scenes (using lighting

and shading) Viewing:

displaying images from various viewpoints on

various devices


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Where did this image come from?

What hardware/software did we need to produce it?

An Example


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Application: The object is an artists impressionof the sun for an animation

Software: used for modeling and rendering

Hardware: PC with graphics card for modelingand rendering

An Answer


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Basic Graphics System

Input devices

Output device

Image formed in FB


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Can be used either as a line-drawing device(calligraphic) or to display contents of frame

buffer (raster mode)

CRT


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Computer graphics goes back to the earliest days ofcomputing

Strip charts

Pen plotters

Simple displays using A/D converters to go from computer tocalligraphic CRT

Cost of refresh for CRT too high Computers slow, expensive, unreliable

Computer Graphics: 1950-1960


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Wireframe graphics

Draw only lines

Sketchpad

Display Processors Storage tube


wireframe representation

of sun object


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Introduced by Ivan

Recognized the potential of man-machine interaction

Loop

Display something

User moves light pen

Computer generates new display

Sutherland also created many of the now common algorithmsfor computer graphics

Sketchpad


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Rather than have the host computer try to refreshdisplay use a special purpose computer called adisplay processor (DPU)

Graphics stored in display list (display file) ondisplay processor

Host compiles display list and sends to DPU

Display Processor


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Raster Graphics

Beginning of graphics standards IFIPS

GKS: European effort

Becomes ISO 2D standard

Core: North American effort

3D but fails to become ISO standard

Workstations and PCs



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Image produced as an array (the raster) of pictureelements (pixels) in theframe buffer

Raster Graphics


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Allows us to go from lines and wire frame images tofilled polygons

Raster Graphics


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Although we no longer make the distinction betweenworkstations and PCs, historically they evolved fromdifferent roots

Early workstations characterized by

Networked connection: client-server model

High-level of interactivity

Early PCs included frame buffer as part of user memory

Easy to change contents and create images

PCs and Workstations


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Realism comes to computer graphics


smooth shading environment

mapping

bump mapping


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Special purpose hardware Silicon Graphics geometry engine

VLSI implementation of graphics pipeline

Industry-based standards PHIGS

RenderMan

Networked graphics: X Window System

Human-Computer Interface (HCI)



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OpenGL API

Completely computer-generated feature-lengthmovies (Toy Story) are successful

New hardware capabilities Texture mapping

Blending

Accumulation, stencil buffers



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Photorealism

Graphics cards for PCs dominate market Nvidia, ATI, 3DLabs

Game boxes and game players determine direction ofmarket

Computer graphics routine in movie industry: Maya,Lightwave

Programmable pipelines

Computer Graphics: 2000-


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List the modern hardware used in ComputerGraphics today and the features that make themsuitable for CG

List the Modern Softwares for CG and thecapabilities they offer

What are some challenges inherent in CG to date?

Exercise

Intro to Computer Graphics - Wk1

Documents

Transcript of Intro to Computer Graphics - Wk1