Lattice-Boltzmann Lighting

A new technique for lighting participating media is suggested. The technique is based on the lattice-Boltzmann method, which is gaining popularity as alternative to finite-element methods for flow computations, due to its ease of implementation and ability to handle complex boundary conditions. A relatively simple, grid-based photon transport model is postulated and then shown to describe, in the limit, a diffusion process. An application to lighting clouds is provided, where cloud densities are generated by combining two well-established techniques. Performance of the new lighting technique is not real-time, but the technique is highly parallel and does offer an ability to easily represent complex scattering events. Sample renderings are included.