Hardware accelerated per-texel ambient occlusion mapping

Abstract

Ambient occlusion models the appearance of objects under indirect illumination. This effect can be combined with local lighting models to improve the real-time rendering of surfaces. We present a hardware-accelerated approach to precomputing ambient occlusion maps which can be applied at runtime using conventional texture mapping. These maps represent mesh self-occlusion computed on a per-texel basis. Our approach is to transform the computation into an image histogram problem, and to use point primitives to achieve memory scatter when accumulating the histogram. Results are presented for multiple meshes and computation time is compared with a popular alternative GPU-based technique. © Springer-Verlag Berlin Heidelberg 2008.