Real time image based volume lighting

Cyril Delalandre, Pascal Gautron, Jean-Eudes Marvie

Abstract

We propose a two-step, GPU-friendly technique for real-time rendering of heterogeneous participating media under distant environment lighting. First, our algorithm estimates the spherical scattered radiance at a number of points in the medium and projects this function into the spherical harmonics basis. In the second step we render use the scattered radiance information to compute single scattering by ray-marching. Our method is easy to implement using GPu shaders and does not require any precomputation, hence supporting dynamic lighting, animated media, dynamic optical properties of the volume, emission and self-shadowing