“Fast, soft reflections using radiance caches” by Shah, Ritter, King and Gronsky
Conference:
Type(s):
Title:
- Fast, soft reflections using radiance caches
Session/Category Title: Oh, Rats!
Presenter(s)/Author(s):
Abstract:
In Pixar’s Ratatouille a lot of scenes take place inside the kitchen where reflective surfaces like counter tops, stoves, pots and pans abound. Furthermore, these surfaces were often burnished or covered with dents, scratches or other displacements, which meant that the reflections were soft and fuzzy. Physically accurate reflections are most often achieved by tracing reflected rays into the scene. When the ray encounters another object, computationally expensive lighting and shading calculations must be performed to determine the contribution of the reflecting point. Paradoxically, surfaces that have soft or fuzzy reflections are more expensive since they have a larger reflection cone angle requiring more rays to adequately sample the reflected scene. We present a technique that utilizes radiance caches to significantly speed up the reflection calculations and discuss some of the accuracy trade-offs inherent to this approach.
References:
1. CHR87 — Robert Cook, Loren Carpenter, Edwin Catmull, The Reyes image rendering architecture, Proceedings of ACM Siggraph 1987.
2. CHR04 — Baking 3D Textures: Point Clouds and Brick Maps, PhotoRealistic RenderMan Application Note #39, Pixar 2004.
3. CHR07 — Per Christensen, Point Clouds and Brick Maps for Movie Production. Chapter in Point-Based Graphics, Markus Gross and Hanspeter Pfister editors, Morgan Kaufmann Publishers, 2007.
