Ray Tracing Point Sampled Geometry

Abstract

We present a novel technique for ray tracing geometry represented by points. Our approach makes it possible to render high quality ray traced images with global illumination using unstructured point–sampled data thus avoiding the time-consuming process of reconstructing the underlying surface or any topological information. Com- pared with previous point rendering methods, our approach allows for more complex illumination models while still maintaining the simplicity of the point primitive. Intersections with the point–sampled geometry are detected by tracing a ray through the scene until the local density of points is above a predefined threshold. We then use all the points within a fixed distance of the ray to interpolate the position, normal and any other attributes of the intersection. The considered distance from the ray must be larger than the largest “hole” among the points. We demonstrate results for soft shadows, reflection and refraction, global illumina- tion and subsurface scattering.