A practical shading model for ray tracing

Abstract

Photorealistic rendering relies on informative descriptions of its scenes. In particular, the material properties of 3D objects is important to achieve convincing results. The material of an object details how it interacts with light, for instance the color, transparency, and the sharpness of its reflections. What arises in practice is finding a brief description that allows for a wide range of materials to be represented, while preserving photorealism - in other words, a practical material system. These constraints mean that the material parameters should be few and easy to understand, and creating the material definitions themselves must be simple. This report outlines a shading model that attempts to deal with these issues, and presents a collection of base material types that exposes only a few, but powerful, parameters for artists to work with.