A Hierarchical Volumetric Shadow Algorithm for Single Scattering

Rendering volumetric shadows in participating media requires integrating scattering over view rays. Left: The visibility component of this integral has a special structure: once a light ray hits an occluder, that light ray does not contribute to the integral along any view ray past the occluder. Middle: Our method exploits this structure by computing the integrals in an epipolar coordinate system, in which light rays (dashed grey) and view rays (solid black) are orthogonal and the integration can be performed asymptotically efficiently using a partial sum tree. Right: This enables us to compute high-quality scattering integrals much faster than the previous state of the art.

Authors: 
Ilya Baran (MIT CSAIL)
Jiawen Chen (MIT CSAIL)
Jonathan Ragan-Kelley (MIT CSAIL)
Frédo Durand (MIT CSAIL)
Jaakko Lehtinen (MIT CSAIL)
Publication Date: 
Wednesday, December 1, 2010
Research Area: