Texel Shading

Abstract

We have developed a texture space shading system built on modern graphics hardware. It begins with a conventional rasterization stage, but records texel accesses as shading work rather than running a shade per pixel. Shading is performed by a separate compute stage, storing the results in a texture. As a baseline, the texels correspond to those required for mipmapped texturing. A final stage collects data from the texture. Storing results in a texture allows for reuse across frames. We also show how adapting shade rate to less than once per pixel further increases performance. We vary shading load to show when these techniques provide a performance win, with up to 4.1x speedup in our experiments at shading times less than 4 ms.