Light meshes-original approach to produce soft shadows in ray tracing

Abstract

The given paper is devoted to the application of the original approach of Light Meshes to the recursive ray tracing algorithm. It is a sort of a simulation of a solution for the global illumination problem. It consumes not so much extra computational time and. nevertheless. allows: a) to speedup a process of shadow calculations, b) to build soft shadows, c) to simulate main effects of diffuse interrefiections, d) to omit the ambient term. In order to obtain the goals listed above we introduce the notion of space light meshes. A light mesh is a point set (mesh points) in 3D space of a scene. At each mesh point we compute illuminance, which characterizes some kind of "light, field intensity" in the scene. Then important part of resulting illumination of a scene object. point (object point) is obtained via interpolation of stored values of nearby mesh points. Our experiments show that the suggested approach reduces computational time with respect to ray tracing algorithm if a scene contains a lot. of light sources and/or an image has a large resolution. © Springer-Verlag Berlin Heidelberg 2002.