Sampling Precomputed Volumetric Lighting

Precomputing volumetric lighting allows realistic mutual shadowing and reflections between objects with little runtime cost: for example, using an irradiance volume the shadows and reflections due to a static scene can be precomputed into a three-dimensional grid and this grid can be used to shade moving objects at runtime. However, a rather low spatial resolution has to be used to keep the memory requirements acceptable. For this reason, these methods often suffer from aliasing artifacts. In this article we introduce a new sampling algorithm for precomputing lighting into a regular three-dimensional grid. The advantage of the new method is that it dramatically reduces aliasing while adding only a small overhead for the precomputation time. Additionally, the runtime component does not have to be changed at all.