Area Lights Voxelization for Light Propagation Volumes

Simulation of the area light sources direct illumination is a topic of interest in the field of Computer Graphics. In the real world, all light sources have a surface from which light is emitted. Thus, for a physically correct simulation of the light transport in graphical applications, area light sources are required. In addition, there are complex lighting effects that can only be simulated with such light sources. In this paper, we present an improvement of the direct lighting simulation for area light sources within the real-time global illumination technique called light propagation volumes. Our method is based on a voxelization of the area light source geometry in a voxel volume of the same resolution as the light propagation volume used in the global illumination technique. With a sample for every voxel that intersects a triangle, for every triangle of the mesh, we obtain an optimal distribution of the samples needed to approximate the direct illumination of the area light source for the light propagation volumes technique.