Especially with the recent programmable features of graphics hardware, procedural graphics has become quite popular. Unlike stored graphics, procedural models and textures can provide effectively infinite resolution and detail and can extend infinitely long in all dimensions, limited only by numerical precision and magnitude. Because procedural models and textures are generated, their algorithms are very compact, requiring the storage of a short machine-code program or even just a sequence of parameters, resulting in an effectively limitless number of different textures and models available to a given scene.

A wide variety of tools exist (or did at one time) to support procedural modeling and texturing, including Renderman , Exluna/BMRT (RIP), Mojoworld , OpenGL 2.0 , Cg , RenderMonkey, RTSL , and others. Unfortunately while each of these has benefits, they also have drawbacks. The Renderman Shading Language is currently the industry standard, but renderers are no longer freely available and it isn't the best choice for the real-time graphics used for games and environments. A large number of SDK's and languages have been developed for programming graphics accelerators, but these too have limitations, including the necessity of understanding the difference between a vertex shader and a pixel shader.

For the past ten years I have been creating a scene description language called Procedural Geometric Instancing. PGI is based on the scene graph found in most graphics libraries like VRML, Direct 3D and the ill-fated Farenheit, but has procedural extensions that allow it to generate some of the same models as L-systems. Over ten years of development has left our existing PGI renderer in a heap of kludges and spaghetti code. The new Texturing and Modeling book will have a chapter on PGI so we are using that book and this course as an opportunity to rewrite an updated version of PGI. The class projects will all be different components of the PGI renderer. Because we will all be working on different components of the same project, this will foster student collaboration instead of student competition. The result will also be something each student can point to, and each student will receive credit for their contribution to the PGI renderer.

Course Goals

• To understand the concepts, algorithms and data structures behind procedural modeling and shading.
• To gain experience with the tools available for procedural graphics.
• To be aware of recent hardware support for programmable shading.
• To contribute to the PGI procedural scene graph project.

Prerequisites

• CS 318 - Introduction to Computer Graphics
• CS 319 - Advanced Computer Graphics
• Or consent of the instructor

Projects

• See the project page.

Outline

(The titles in bold are have restricted access. They can be accessed from PC's in the uiuc.edu domain, or through the library's proxy server.)

• 8/29 - Introduction/Overview
• 9/3 - L-Systems (html) (ppt ) (pdf )
• 9/5 - Iterated Function Systems (html) (ppt ) (pdf ) and notes (pdf ).
• 9/10 - Scene Graphs (html) (ppt) (pdf) 
• 9/12 - Procedural Geometric Instancing (html) (ppt) (pdf) 
• 9/17 - Programmable Graphics Hardware (html) (ppt) (pdf) 
• 9/19 - A Programmable Shading Pipeline Grammar (html) (ppt) (pdf) 
• 9/24 - Noise, by Navreet Gill
  • Lewis, Algorithms for solid noise synthesis , Proc. SIGGRAPH 89
  • Worley,  A cellular texture basis function , Proc. SIGGRAPH 96
• 9/26 - Implementing Noise, by Hart
  • Hart, Perlin-Noise Pixel Shaders , Proc. Graphics Hardware 2001
  • Perlin, Improving noise , Proc. SIGGRAPH 2002
• 10/1 - Shadows, by Brad Jones
  • Everitt et al. , Hardware Shadow Mapping, NVidia.
  • Everitt & Kilgard, Practical and Robust Stenciled Shadow Volumes for Hardware-Accelerated Rendering, NVidia.
• 10/3 - Real-Time Procedural Solid Texturing, by Nate Carr
• 10/8 - Bump Mapping, by Zhuoshi Chen
  • Bump Mapping Documentation
• 10/10 - NVidia Graphics overview, by Shreeganesh Ramanan
  • Cg Language, Cg toolkit
  • Kilgard, NV30 OpenGL Extensions.
• 10/15 - Multitextured BRDF evaluation, Sebastian Magda
  • McCool et al., Homomorphic factorization of BRDFs for high-performance rendering, Proc. SIGGRAPH 2001
  • Lata & Kolb, Homomorphic factorization of BRDF-based lighting computation, Proc. SIGGRAPH 2002
• 10/17 - GPU Compilers, by Jesse Hall
• 10/21 (MONDAY, 4PM, 1320 DCL) - Distinguished Lecture, David Kirk, Chief Scientist, NVidia.
• 10/22 - NVidia Q&A
• 10/24 - Modeling Patterns, by Samuel Atlan
  • Legakis et al.,  Feature-based cellular texturing for architectural models, Proc. SIGGRAPH 2001
  • Walter et al., Integrating shape and pattern in mammalian models, Proc. SIGGRAPH 2001
• 10/29 - Surface Texture Synthesis, by Shuo-Heng Chung 
  • Turk, Texture synthesis on surfaces, Proc. SIGGRAPH 2001
  • Wei & Levoy,  Texture synthesis over arbitrary manifold surfaces, Proc. SIGGRAPH 2001
• 11/5 - Modeling cities, by Don Schmidt
  • Parish & Muller, Procedural modeling of cities, Proc. SIGGRAPH 2001
• 11/12 - Solid models, by Dylan Smith
  • Cutler et al., A procedural approach to authoring solid models, Proc. SIGGRAPH 2002
• 11/14 - Bounding Volumes, by Orion Sky Lawlor
  • Rice, Spatial bounding of self-affine iterated function system attractor sets, Proc. Graphics Interface '96
• 11/19 - Rendering of Procedural Terrain, by Jared Hoberock
• Musgrave, QAEB Rendering for Procedural Models with Adaptive Levels of Detail, chapter in Texturing & Modeling.
• 11/21 - Reverse engineering trees, by Andrew Wu
• Prusinkiewicz et al., The use of positional information in the modeling of plants, Proc. SIGGRAPH 2001
• Shlyakhter et al., Reconstructing 3D Tree Models from Instrumented Photographs, CG&A 21(3)
• 12/3 - Animation, by Joyce Chau
• Prusinkiewicz, Hammel and Mjolsness. Animation of plant development, Proc. of SIGGRAPH 93
• 12/3 (bonus) - L-Systems for Subdivision Surfaces, by Brian Bosse
• 12/5 - Particle Systems, by Wen Su
  • Fleischer et al., Cellular texture generation, Proc. SIGGRAPH 95.
• 12/5 (bonus) - Fire, by Mark Flider
  • Lamorlette & Foster, Structural modeling of flames for a production environment , Proc. SIGGRAPH 2002

Books

• Real-Time Shading , by Olano, Hart, Heidrich and McCool, AK Peters, July 2002.
• Texturing and Modeling: A Procedural Approach , Third Edition, by Ebert, Musgrave, Peachey, Perlin and Worley, Morgan Kauffman, Nov. 2002. (The third edition has a lot of additions for the real-time procedural modeling and shading used for game development, including new chapters by Bill Mark and myself.)