Non-linear approximation of reflectance functions

We introduce a new class of primitive functions with non-linear parameters for representing light reflectance functions. The functions are reciprocal, energy-conserving and expressive. They can capture important phenomena such as off-specular reflection, increasing reflectance and retro-reflection. We demonstrate this by fitting sums of primitive functions to a physically-based model and to actual measurements. The resulting representation is simple, compact and uniform. It can be applied efficiently in analytical and Monte Carlo computations. CR Categories: I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism; I.3.3 [Computer Graphics]: Picture/Image Generation

• Type: Conference
• Year: 1997
• Where: SIGGRAPH
• Authors: Eric P. Lafortune, Sing-Choong Foo, Kenneth E. Torrance, Donald P. Greenberg
• Keywords: Computer Graphics, Light Reflectance Functions, Primitive Functions, SIGGRAPH 1997