Rendering

FACULTY

Greg Turk

SCOPE

Rendering is the process of creating images from scene descriptions. Relevant topics in this area include image sampling, anti-aliasing, texture synthesis, texture mapping, scan conversion, radiance, light fields, BRDF's (surface reflectance), ray tracing, radiosity, the reflectance equation, the rendering equation, volume rendering and image-based rendering.

SUGGESTED READINGS

  1. James Foley, Andries van Dam, Steven Feiner and John Hughes, Computer Graphics: Principles and Practice, Addison Wesley, second edition in C, 1996, Chapters and Sub-Chapters 3.2, 3.6, 3.17, 14, 15, 16, 19.3.1.
  2. Ken Perlin, "An Image Synthesizer," SIGGRAPH 85, pp. 287-296.
  3. Robert Cook, Loren Carpenter and Edwin Catmull, "The Reyes Rendering Architecture," SIGGRAPH 87, pp. 95-102.
  4. James F. Blinn, "What We Need Around Here is More Aliasing", and "The Return of the Jaggies", IEEE Computer Graphics and Applications, January 1989, pp. 75-79 and March 1989, pp. 82-89.
  5. Pat Hanrahan, "Rendering Concepts," in Radiosity and Realistic Image Synthesis, by Michael Cohen and John R. Wallace, Chapter 2, Academic Press, 1993, ISBN 0-12-178270-0, pp. 13-40.
  6. Pierre Poulin and Alain Fournier, "A Model for Anisotropic Reflectance," SIGGRAPH 90, pp. 273-282.
  7. Robert L. Cook, Thomas Porter, and Loren Carpenter, "Distributed Ray Tracing," SIGGRAPH 84, pages 137-45, July 1984.
  8. James Kajiya, "The Rendering Equation," SIGGRAPH 86, pp. 143-150.
  9. Eric Veach and Leonidas Guibas, "Metropolis Light Transport," SIGGRAPH 97, pp. 65-76.
  10. Michael F. Cohen, Shenchang Eric Chen, John R. Wallace, and Donald P. Greenberg. "A Progressive Refinement Approach to Fast Radiosity Image Generation," SIGGRAPH 88, pages 75-84, August 1988.
  11. Marc Levoy, "Display of Surfaces from Volume Data," IEEE Computer Graphics and Applications, Vol. 8, No. 3 (May 1988), pp. 29-37.
  12. Westover, Lee, "Footprint Evaluation for Volume Rendering," SIGGRAPH 90, pp. 367-376.
  13. Marc Levoy and Pat Hanrahan, "Light Field Rendering," SIGGRAPH 95, pp. 31-42.

SUGGESTED COURSES

SAMPLE QUESTIONS

  1. Describe the meaning of the terms pre-filtering, sampling, and reconstruction of digital signals as they relate to aliasing.
  2. Define radiance, light field, BRDF. What are the relations between these in a given static scene?
  3. What is the reflectance equation? What do each of the symbols in it mean? How do we approximate it in standard Whitted-style ray tracing? What aspects of it are neglected in standard ray-tracing?
  4. What effects can be captured using distribution ray tracing? How are each of these effects related to aliasing, if at all? What lighting effects will distribution ray tracing NOT capture.
  5. What are the properties of Perlin noise? How can one generate it? Give two specific examples of using it to make solid textures.
  6. Describe a simple scene with diffuse polygons and diffuse lights. Set up the matrix system that is used to calculate radiosity for your scene, being as specific as possible.
  7. Describe in detail a ray tracing based rendering system that captures diffuse illumination effects of the kind that radiosity produces. What are likely noticeable artifacts (errors) of the approach that you describe and what might be done to overcome them?
  8. What are the speed and quality tradeoffs between the various volume rendering techniques that you know? Describe these strengths and weaknesses for as many ways as you can for volume rendering.
  9. Describe a particular image-based rendering system. Discuss aliasing issues that can arise in the system and describe several potential ways to improve the image quality.