Level-of-Detail Shaders

Current graphics hardware can render objects using simple procedural shaders in real-time. However, detailed, highquality shaders will continue to stress the resources of hardware for some time to come. Shaders written for film production and software renderers may stretch to thousands of lines. The difficulty of rendering efficiently is compounded when there is not just one, but a scene full of shaded objects, surpassing the capability of any hardware to render. This problem has many similarities to the rendering of large models, a problem that has inspired extensive research in geometric level-of-detail and geometric simplification. We introduce an analogous process for shading, shader simplification. Starting from an initial detailed shader, shader simplification produces a new shader with extra level-of-detail parameters that control the shader execution. The resulting level-of-detail shader, can automatically adjust its rendered appearance based on measures of distance, size, or importance as well as physical limits such as rendering time budget or texture usage. CR categories and subject descriptors: I.3.3 [Computer Graphics]: Picture/Image generation — Display algorithms; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism — Color, shading, shadowing and texture.