Path Traced Subsurface Scattering using Anisotropic Phase Functions and Non-Exponential Free Flights

Magnus Wrenninge, Ryusuke Villemin, Christophe Hery


With the recent move to path tracing for both surface and volume rendering, subsurface scattering has been one of the last light transport modes to rely on empirical or approximate models. Although rendering of subsurface scattering using path tracing is conceptually simple, making the model artist friendly is not. Our new model is an unbiased subsurface scattering estimator that retains the controllability of the previous models, while introducing both anisotropic (directional) scattering as well as non- exponential free flights, which enables artistic control over the depth of light bleed without losing fine detail.

Paper (PDF)

Additional materials: [PTSSSAlbedoInversionCoeffs.txt]

Available as Pixar Technical Memo #17-07