Multiple Scattering Approximation in Heterogeneous Media by Narrow Beam Distributions
Computer Graphics Forum (Proceedings of Pacific Graphics 2016), Vol. 35, No. 7, pp. 373-382

Mikio Shinya1,  Yoshinori Dobashi2,  Michio Shiraishi3,  Motonobu Kawashima4
Tomoyuki Nishita5
1Toho University/UEI Research,  2Hokkaido University/UEI Research,  3Toho University,  4Momomo Works Inc.,  5UEI Research/Hiroshima Shudo University

Fast realistic rendering of objects in scattering media is still a challenging topic in computer graphics. In presence of participating media, a light beam is repeatedly scattered by media particles, changing direction and getting spread out. Explicitly evaluating this beam distribution would enable efficient simulation of multiple scattering events without involving costly stochastic methods. Narrow beam theory provides explicit equations that approximate light propagation in a narrow incident beam. Based on this theory, we propose a closed-form distribution function for scattered beams. We successfully apply it to the image synthesis of scenes in which scattering occurs, and show that our proposed estimation method is more accurate than those based on the Wentzel-Kramers-Brillouin (WKB) theory.

paper:[pdf] video:[mp4]

    author  = {Mikio Shinya and Yoshinori Dobashi and Michio Shiraishi and Motonobu Kawashima and Tomoyuki Nishit},
    title   = {Multiple Scattering Approximation in Heterogeneous Media by Narrow Beam Distributions},
    journal = {	Computer Graphics Forum (Proceedings of Pacific Graphics 2016)},
    year    = {2016},
    volume  = {35},
    number  = {7},
    pages   = {373-382}
This research was partially supported by JSPS KAKENHI, Grant-in-Aid for Scientific Research on Innovative Areas, Grant Number JP15H05924.