Introduction
Triangle based scene representations are very popular in interactive computer graphics due to the fast rasterization made possible by advances in graphics hardware. In recent years, the amount of geometry in a scene has grown rapidly, to a point where triangle rasterization is no longer the most efficient rendering technique. In such situations, a representation based on point samples of the geometry can be an excellent alternative due to its relatively lighter memory footprint, and representational simplicity.
We develop a fast, parallel raytracer for point models on Graphics Processing Units (GPUs). Our contributions include a fast, octree based raytracing primitive on the GPU, techniques to handle ray-surface intersections, and a realtime raytracer that incorporates reflection, refraction, shadows, diffuse illumination, caustics and textures. We evaluate two techniques for raytracing point data, a splat-based approach, and an implicit surface approach.
