Unifying Points, Beams, and Paths in Volumetric Light Transport Simulation
Efficiently computing light transport in participating media in a manner that is robust to variations in media density, scattering albedo, and anisotropy is a difficult and important problem in realistic image synthesis.
July 27, 2014
ACM SIGGRAPH 2014
Authors
Jaroslav Křivánek (Charles University, Prague)
Iliyan Georgiev (Light Transportation Ltd.)
Toshiya Hachisuka (Aarhus University)
Petr Vévoda (Charles University, Prague)
Martin Šik (Charles University, Prague)
Derek Nowrouzezahrai (Université de Montréal)
Wojciech Jarosz (Disney Research)
Unifying Points, Beams, and Paths in Volumetric Light Transport Simulation
Efficiently computing light transport in participating media in a manner that is robust to variations in media density, scattering albedo, and anisotropy is a difficult and important problem in realistic image synthesis. While many specialized rendering techniques can efficiently resolve subsets of transport in specific media, no single approach can robustly handle all types of effects. To address this problem we unify volumetric density estimation, using point and beam estimators, and Monte Carlo solutions to the path integral formulation of the rendering and radiative transport equations. We extend multiple importance sampling to correctly handle combinations of these fundamentally different classes of estimators. This, in turn, allows us to develop a single rendering algorithm that correctly combines the benefits and mediates the limitations of these powerful volume rendering techniques.
