Linear-Time Algorithms for Finding the Shadow Volumes from a Convex Area Light Source

Abstract.

An area light source in three-dimensional space shines past a scene polygon to generate two types of shadow volumes for each scene polygon, i.e., one with partial occlusion and the other with complete occlusion. These are called penumbra and umbra, respectively. In this paper we propose linear-time algorithms for computing the penumbra and the umbra of a scene polygon from an area light source, respectively.