Real-Time Screen-Space Scattering in Homogeneous Environments

The proposed approximate algorithm computes light scattering in homogeneous participating environments in screen space. Instead of simulating full global illumination, this method models scattering by a physically based point spread function (PSF). To do this efficiently, the PSF is applied by performing a discrete hierarchical convolution in a texture MIP map. This method's main problem, illumination leaking, is solved through a custom anisotropic incremental filter. The solution is fully parallel, runs in hundreds of fps for the usual screen resolutions, and is directly applicable in most 2D and 3D rendering architectures. © 1981-2012 IEEE.