Tracing specular light paths in point-based scenes

Massive point data sets representing meticulous details of various heritage sites and statues are now becoming available due to recent advances in multi-view stereo techniques. Photorealistic rendering of such point sets has not yet, however, matched their polygonal counterparts with respect to the interactivity of applications as well as the quality of light simulations. In this paper, we present a framework for tracing specular light paths in massive point model environments at interactive frame rates on Graphics Processing Units (GPUs). We introduce the Sample Octree (S-Octree), a lightweight data structure for efficient, sampled representation of point set information. The Implicit Surface Octree (ISO), an instance of the S-Octree, provides a compact representation of point set surfaces. The ISO defines a local manifold approximation of the input point data. The Caustic Sample Map (CSM), another instance of the S-Octree, represents contributions of caustic paths. These data structures enable us to further the state of the art by demonstrating reflections, refractions, shadows and caustic effects on massive, complex point models at interactive frame rates.