Enhancements to Directional Coherence Maps

Directional Coherence Maps as proposed by Guo in ’98 are a very efficient acceleration technique for ray tracing based global illumination renderers. It vastly reduces the number of pixels which have to be computed exactly by identifying regions which are suitable for interpolation. By using oriented finite elements for interpolation, the sampling density can be kept low for large regions of the target image. In this paper we describe extensions of the method. An improved object test is presented which prevents that small objects are missed. Additionally, it is shown how to handle textures efficiently, which was not possible with the original approach.