Improved Volume Scattering

Abstract

This paper examines two approaches to improve the realism of volume scattering functions. The first uses a convex combination of multiple Henyey-Greenstein distributions to approximate a more complicated scattering distribution, while the second allows negative coefficients. The former is already supported in some renderers, the latter is not and carries a significant performance penalty. Chromatic scattering is also explored, and found to be beneficial in some circumstances. Source code is publicly available under an open-source license.