A global illumination solution for general reflectance distributions

A general light transfer simulation algorithm for environments composed of materials with arbitrary reflectance functions is presented. This algorithm removes the previous practical restriction to ideal specular and/or ideal diffuse environments, and supports complex physically based reflectance distributions. This is accomplished by extending previous two-pass ray-casting radiosity approaches to handle non-uniform intensity distributions, and resolving all possible energy transfers between sample points. An implementation is described based on a spherical harmonic decomposition for encoding both bidirectional reflectance distribution functions for materials, and directional intensity distributions for illuminated surfaces. The method compares favorably with experimental measurements.

• Type: Conference
• Year: 1991
• Where: SIGGRAPH
• Authors: François X. Sillion, James Arvo, Stephen H. Westin, Donald P. Greenberg
• Keywords: Arbitrary Reflectance Functions, Computer Graphics, Intensity Distributions, Reflectance Distribution, SIGGRAPH 1991