1. CSc 4820/6820 Computer Graphics Algorithms
Overview of 3D Computer Graphics

2. Outline A brief history of computer graphics
Computer graphics applications
Difficulties of developing computer graphics
Major conferences, journals

3. Computer Graphics: A Brief History
William Fetter of Boeing coins the term “Computer Graphics” (1960)
Basic computer graphics algorithms/concepts are introduced: hidden line detection, homogeneous coordinates, line drawing, back-face culling, parametric curves & surfaces, etc.
Spacewars, first video game, is developed at MIT (1961)
SketchPad: first interactive computer graphics software (1962)
First Head Mounted Display is developed at MIT (1968)
Bell Labs builds first frame buffer (3 bits)
First use of CGI for commercials – MAGI for IBM (1969)
SIGGRAPH is formed (1969)
Spacewars
Image courtesy MIT Media Lab

4. Computer Graphics: A Brief History
Many fundamental computer graphics algorithms/technologies are introduced: visible surface detection, Gouraud shading, Phone shading, Z-buffer, curved surface rendering, texture mapping, reflectance and environment mapping, anti-aliasing, curved shadow, bump mapping, ray tracing, keyframe based animation, etc.
First SIGGRAPH conference (1973)
Microsoft is founded (1974); Special effects powerhouse, Industrial Light & Magic, is founded (1975)
The first flight simulator for Apple II is released (1978) (later purchased by Microsoft)
First flight simulator
Image courtesy simflight.com

5. Computer Graphics: A Brief History
Many major companies in the graphics field are founded: Silicon Graphics Inc., ATI, SUN, Pixar, Adobe, AutoDesk, Alias, Softimage, Side Effects, etc.
More graphics algorithms are introduced: radiosity, motion capture, motion blur, morphing, etc.
The birth of RenderMan (1988)
Wavefront – the first commercially available 3D software package (1984)
AutoCAD 1.0 (1982)
Tron (1982): 1st film to make extensive use of computer graphics
Tron

6. Computer Graphics: A Brief History
The release of major 3D graphics libraries: OpenGL, DirectX, Java3D
Image based rendering attracts attention
The release of major 3D modeling & animation packages: 3D Studio, 3D Studio Max, Maya, etc.
The rise and fall of SGI
NVIDIA releases first Graphics Processing Unit (1999)
Increasing use of 3D special effects in feature films: Terminator 2, Titanic, etc.
First 3D computer animated feature film: Toy Story by Pixar
The release of Doom and Quake
CAVE: immersive virtual environment
Titanic

7. Computer Graphics: A Brief History
2000 – present
Powerful Graphics Processing Units on PC graphics card: NVIDIA Geforce3/4/FX/6800/7800/8800, ATI Radeon 9700/9800/X800/X850/X1950
High level shading languages: Cg, HLSL, GLSL, Sh, etc.
New generation game console: Xbox/360, Playstation2/3
Widespread use of CGI special effects in feature films: War of the Worlds, Lord of the Rings, Spiderman, Matrix, Finding Nemo, Shrek, The Cars, etc.

8. Major applications Entertainment Training and simulation
Computer Aided Design (CAD), Computer Aided Engineering (CAE), and Computer Aided Manufacturing (CAM)
Medical applications
Scientific visualization
CG art

9. Medical Visualization
Human body modeling
3D medical image visualization
Volume rendering
Virtual surgery simulation
Computer Assisted surgery
Virtual Reality for patient care
E.g. Immersive Virtual Reality for pain control
Modeling human head
Images courtesy Stanford University
Volume Rendering
Images courtesy GE

10. Scientific Visualization
Visualizing and analyzing engineering & scientific data
Bioinformatic visualization
Molecular Modeling
Fluid Dynamics simulation and analysis
3D structure electromagnetic field simulator
E.g. visualization for Data Mining
Collaborative visualization
CAVE: immersive virtual environment
2003 Hurricane Season Forecast
Images courtesy NASA
Collaborative Visualization
Images courtesy SGI

11. Computer Aided Engineering (CAE)
Computer assisted engineering analysis
Finite Element Analysis
Images courtesy SGI

12. Computer Aided Design (CAD) & Manufacture (CAM)
Widespread use of CAD and CAM in manufacture industry
E.g. Automobile design and manufacture
Geometric Modeling
Product design and analysis
Computer Aided Manufacturing
Images courtesy SGI
Computer Aided Design
Images courtesy SGI

13. Visual Simulation
Simulate real world experience using graphics software and hardware
Used for civil or military training, mission planning, etc.
E.g. flight, ground, space, maritime simulation
Flight Simulation
Images courtesy Link Simulation & Training
Marine Simulation
Images courtesy SGI

14. Architectural Visualization & Simulation
Urban simulation for city planning
Real estate preview
Urban Simulation
Images courtesy MultiGen-Paradigm
Real Estate Preview
Images courtesy SGI

15. Art Computer Graphics Art Art preservation
Digital Michelangelo Project
Computer Graphics Art
Images courtesy Dan Raabe, Toolbox Films
Michelangelo’s David
Images courtesy Stanford University

16. Entertainment www.spore.com http://www.killerbeanforever.com/
ean_forever_official_trailer/

17. Why is 3D computer graphics popular?
Graphics related industry is huge and growing
Graphics hardware is advancing rapidly
Creating CG content no longer requires expensive hardware
Most of the development is done on PC now
CG software packages (Maya, 3DS Max, DirectX, OpenGL) has matured
Open source tools like Blender have also matured
Both graphics hardware and software are relatively cheap now

18. Web sites for CG information
Major companies’ web sites (nVidia, AMD, Alias, Discreet, etc.)
News:

19. How to search and find papers?
The most comprehensive database of CG publications
Most of the recent journal papers are online
Find them through GSU library web page: E-journal Locator
SIGGRAPH papers since 1974 are also online
Go to and search for “computer graphics” and then click on “computer graphics proceedings …”
Search by paper title on Google.
Find one of the authors’ homepage. They often have links to their papers.

20. Notable companies Software Hardware NVIDIA (GeForce card, Cg)
ATI (Radeon card), acquired by AMD
3Dlabs (OpenGL, OpenGL Shading Language)
Intel (integrated graphics chipset)
Software
Microsoft (DirectX, games)
AutoDesk (3D Studio Max, AutoCAD, Maya)
SoftImage (SoftImage)

21. Notable companies Animation film studio Visual special effects
Pixar, DreamWorks, etc.
Visual special effects
Industrial Light & Magic, Rhythm and Hues, etc.
e_visual_effects_companies

22. Notable companies Game Other
Electronic Arts
Sony
Microsoft
Other
Adobe
Apple
For a more comprehensive list, visit SIGGRAPH exhibitor directory at ibition/

23. How to develop 3D graphics applications
Write programs
Use modeling and animation tools
Use either one or both

24. Graphics APIs OpenGL DirectX Tools
(gDebugger, a OpenGL debugging tool)

25. Shading languages and tools
OpenGL Shading Language
High Level Shading Language in DirectX Cg
Tools
RenderMonkey
CgFX viewer

26. Modeling and animation tools
Maya and 3DS Max
Maya Personal Learning Edition (PLE)
?siteID=123112&id=
Softimage
Lightwave3D
and many many more …

27. Blender Blender (www.blender3d.com)
A free 3D modeling, animation, and rendering tool

28. Creating 3D Graphics Content
Different ways to create graphics content
If you want to create non-interactive 3D animations
Use graphics modeling/animation tools: 3DS Max, Maya, Blender, etc.
If you want to create interactive 3D applications (game, training & simulation program)
A combination of both modeling/animation tools and programming
C/CPP + scene graph + OpenGL/D3D + Shader

29. Graphics Libraries (APIs)
3D graphics applications are built on top of graphics libraries
A collection of graphics routines that an application program can call
The APIs hide the underlying complexity of graphics hardware and/or lower level APIs
Large scale graphics applications are usually built on top of high level graphics APIs

30. Graphics Libraries (APIs)
High level APIs are implemented on top of low level graphics APIs
Low level APIs control graphics hardware through graphics drivers
Between low level graphics APIs and graphics drivers there are shader libraries

31. High Level Graphics APIs
Also known as Scene Graph APIs
Non-real-time oriented APIs
VRML & X3D
Open Inventor
Renderman
Java3D

32. High Level Graphics APIs
Real-time oriented APIs
3D graphics and game engines
Unity3D
Unreal Development Kit
Torque Game Engine
OGRE
OpenGL Performer
Open Scene Graph
OpenSG
Many proprietary high level APIs

33. Game Engines Game engine
Graphics API designed specifically for game development
Contains all non-content related functions/elements

34. Game Engine Game Architecture Gameplay Game engine Tools & Editor
Graphics Hardware

35. Modern Game Engine Features
Scene management
Culling,
Rendering
Bump mapping
Shadow
Collision
Decals AI
Particle systems, etc.
Shader management

36. Game Engines There are hundreds of game engines
Most popular game engines
Unreal Development Kit
Unity3D
Torque Game Engine
OGRE (open source)
For a comprehensive list, check out

37. Unity3D A multiplatform game development tool
A GUI for game development

38. Torque Game Engine
A very popular game engine with multi-player network code, indoor/outdoor rendering engines, skeletal animation, drag and drop GUI creation, a built in world editor, and a C- like scripting language.

39. OGRE Object-oriented Graphics Rendering Engine
A scene-oriented, flexible 3D engine written in C++ designed to make it easier and more intuitive for developers to produce games and demos using 3D hardware.

40. OGRE example

41. OGRE example

42. JOGL Java OpenGL (JOGL) https://jogl.dev.java.net/
A wrapper library that allows OpenGL to be used in the Java programming language

43. OpenGL Performer http://www.sgi.com/products/software/perfor mer/
A graphics API developed by SGI for real-time visual simulation and other performance oriented applications
Implemented on top of OpenGL, with performance as the first priority
mer/
Performer has great influence on other real-time graphics APIs
E.g. Open Scene Graph (

44. Why so many scene graph APIs & game engines?
Different target applications
Real-time vs. non-real-time applications
Application specific optimizations
Application specific entities
E.g. different game genres require different game engines

45. Why so many scene graph APIs & game engines?
Language and platform considerations
Platform specific optimizations
Open source vs. proprietary APIs
Integration of new technologies
Not necessarily a good thing
Lack of documents & sample code

46. Low Level Graphics APIs
Directly handles 3D rendering
Very efficient implementation
Only two major low level 3D graphics APIs
OpenGL
Direct3D (part of DirectX)
Comparison of Direct3D and OpenGL
t3D_and_OpenGL

47. Direct3D Part of Microsoft’s DirectX libraries
Including Direct3D, DirectInput, DirectSound, etc.
Designed for real-time graphics applications
Computer game
Home entertainment
Primary choice for game development
Latest version is DirectX 10
Only supported on MS Windows platform

48. Using Direct3D Benefits Drawbacks
Supported by most of the graphics hardware
Better game support
Better integration with other MS stuff (e.g. .Net)
Maintained by one single company
Quick to add new features to Direct3D
Drawbacks
Somewhat more difficult to learn than OpenGL
Windows only

49. OpenGL Platform independent graphics API Window system independent
MS Windows, Linux, IRIX, Solaris, Mac, etc.
Window system independent
MS Windows, X Window
Maintained by KHRONOS group (an industry consortium)
Members include 3Dlabs, AMD, NVIDIA, Intel, Google, etc.
Current specification: OpenGL 3.0

50. Using OpenGL Benefits Drawbacks http://www.opengl.org/ Open standard
Supported by all the graphics cards
Supported by all the platforms
Lots of books, tutorials, and samples available
Most of the mainstream 3D graphics textbooks use OpenGL
Drawbacks
Historically, OpenGL is often slow to add new features
Users are often forced to use OpenGL extensions

51. OpenGL Extension
OpenGL extensions provide new rendering features above and beyond the features specified in the official OpenGL standard
To keep the OpenGL API current with the latest innovations in graphics hardware and rendering algorithms
Different kind of extensions:
Extensions ratified by the ARB: GL_ARB_multitexture();
Extensions agreed on by multiple vendors: GL_EXT_abgr();
Vendor specific extensions: GL_NV_register_combiners();

52. OpenGL Extension
To find out what OpenGL extensions your graphics card supports, download and install Glview utility (OpenGL extension viewer)

53. OpenGL Related APIs GLU (OpenGL Utility Library)
Mostly modeling related functions: NURBS, tessellators, etc.
Part of OpenGL
GLX: connecting OpenGL with X Window
WGL: connecting OpenGL with MS Windows

54. OpenGL Related APIs GLUT (OpenGL Utility Toolkit)
implements a simple windowing application programming interface (API) for OpenGL
makes it easier to learn OpenGL programming
designed for constructing small to medium sized OpenGL programs
We will use GLUT in this class
Binary files:
Reference manual: 3.html

55. GPU and Shader
Graphics Processing Units are the microprocessors on the newer graphics cards
Nvidia, AMD, and Intel are the main GPU vendors
You can write programs that runs on GPU using a special programming language
These programs are called shaders
The programming languages are called shading languages

56. Shader Programming Why use shaders? Faster and more flexible
To implement features that are not available on OpenGL or Direct3D
Take advantage of GPU, which is is optimized for graphics applications
Faster and more flexible
High level shading languages
Cg, HLSL, OpenGL SL, Sh
Load, compile, and run shader programs from OpenGL or DirectX programs

57. OpenGL Files
OpenGL files comes with MS Windows and/or Visual Studio installation
Header files
gl.h, glu.h
Glut.h (needs to be downloaded)
Static libraries
Opengl32.lib, glu32.lib
glut32.lib (needs to be downloaded)
DLLs
C:\windows\system32
Opengl32.dll, glu32.dll
glut32.dll (needs to be downloaded)

58. How to compile OpenGL/GLUT programs?
ll04-22C151/howto/winGLUT.html
ACTIVE_COMPUTER_GRAPHICS/FOURTH _EDITION/vc

59. Sample OpenGL programs
Examples from “OpenGL Programming Guide”
edbook/
OpenGL code samples:
Simple code samples: imple/

60. A Simple OpenGL Program (1)
#include <GL/glut.h>
void display(void) {
/* clear all pixels */
glClear (GL_COLOR_BUFFER_BIT);
/* draw white polygon (rectangle) with corners at
* (0.25, 0.25, 0.0) and (0.75, 0.75, 0.0) */
glColor3f (1.0, 1.0, 1.0);
glBegin(GL_POLYGON);
glVertex3f (0.25, 0.25, 0.0);
glVertex3f (0.75, 0.25, 0.0);
glVertex3f (0.75, 0.75, 0.0);
glVertex3f (0.25, 0.75, 0.0);
glEnd();

61. A Simple OpenGL Program (2)
/* start processing buffered OpenGL routines */
glFlush (); }
void init (void) {
/* select clearing color */
glClearColor (0.0, 0.0, 0.0, 0.0);
/* initialize viewing values */
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);

62. A Simple OpenGL Program (3)
/* Declare initial window size, position, and display mode (single
buffer and RGBA). Open window with "hello" in its title bar. Call
initialization routines. Register callback function to display graphics.
Enter main loop and process events. */
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize (250, 250);
glutInitWindowPosition (100, 100);
glutCreateWindow ("hello");
init ();
glutDisplayFunc(display);
glutMainLoop();
return 0; /* ANSI C requires main to return int. */ }

63. How to learn OpenGL? Read OpenGL Programming Guide
Read sample programs!
There are tons of OpenGL programs online:
Read tutorials
Write programs

64. How to learn OpenGL? Bookmark the OpenGL manual pages
You need this more than anything else
Bookmark the GLUT manual page
ec3/spec3.html
If you are really serious about learning OpenGL, read OpenGL specification

65. Other OpenGL Resources
OpenGL tutor
Tutorial programs that demonstrate basic OpenGL functionality by allowing the user to modify the parameters of a function and see the effect on the scene
OpenGL FAQ & Troubleshooting Guide
A good OpenGL tutorial