Improved Adaptive Antialiasing for Ray Tracing Implicit Surfaces

Abstract

Interval arithmetic has been extensively used to create guaranteed intersection test when ray tracing implicit surfaces. Aliasing is one of the principal problems in ray tracing, but the interval algorithms are not designed to correct this situation. This paper shows a novel technique to create a guaranteed interval adaptive anti aliasing method (IAA) for interval ray tracing of implicit surfaces. The method is based in the study of the coherence of sets of neighboring rays in a pixel, to detect variations over the hit surface. If those variations are not small enough, the area of the pixel is subdivided and the process is started over the new sub pixels. The subdivision continues until the variations over the surface are small. This method allows us to obtain a better visualization than traditional interval ray tracing.