Abstract: Realistic rendering of materials such as milk, fruits, wax, marble, and so on, requires the simulation of subsurface scattering of light. This paper presents an algorithm for plausible reproduction of subsurface scattering effects. Unlike previously proposed work, our algorithm allows to interactively change lighting, viewpoint, subsurface scattering properties, as well as object geometry.

The key idea of our approach is to use a hierarchical boundary element method to solve the integral describing subsurface scattering when using a recently proposed analytical BSSRDF model. Our approach is inspired by hierarchical radiosity with clustering. The success of our approach is in part due to a semi-analytical integration method that allows to compute needed point-to-patch form-factor like transport coefficients efficiently and accurately where other methods fail.

Our experiments show that high-quality renderings of translucent objects consisting of tens of thousands of polygons can be obtained from scratch in fractions of a second. An incremental update algorithm further speeds up rendering after material or geometry changes.