Specialized shaders for shading objects in computer generated images

Abstract

A computer-implemented shading system includes a geometric renderer which renders a computer generated image to produce geometric image information for an object in a scene, and a user interface which permits a user to selectively vary a designated parameter(s) to affect how that object is shaded. The system also includes a specialized shader to shade the object in the scene according to the designated parameter(s) and other shading parameters. The specialized shader is created from the user's original shader. The specialized shader has a cache loader which contains all of the terms of the user's original shader, plus load operations to load values from computations that do not depend from the designated parameter(s). The specialized shader also has a cache reader which contains a reduced set of terms from the original shader that depend on the designated parameter(s), plus read operations to read the values of the non-variant terms from the cache. When the user designates a parameter(s), the cache loader is executed once to compute the values that will not change when the user varies the designated parameter(s). The cache reader is then executed each time the user alters the value of the designated parameter(s). In this manner, only the computations that are dependent on the designated parameter(s) are recomputed for each alteration, thereby streamlining operation of the entire shading process.