Parallel Solution to the Radiative Transport

László Szirmay-Kalos, Gábor Liktor, Tamás Umenhoffer, Balázs Tóth, Shree Kumar, and Glenn Lupton
Department of Control Engineering and Information Technology, Technical University of Budapest,
Budapest, Magyar tudósok krt. 2, H-1117, HUNGARY


This paper presents a fast parallel method to compute the solution of the radiative transport equation in inhomogeneous participating media. The efficiency of the method comes from different factors. First, we use a novel approximation scheme to find a good guess for both the direct and the scattered component. This scheme is based on the analytic solution for homogeneous media, which is modulated by the local material properties. Then, the initial approximation is refined iteratively. The iterative refinement is executed on a face centered cubic grid, which is decomposed to blocks according to the available simulation nodes. The implementation uses CUDA and runs on a cluster of GPUs. We also show how the communication bottleneck can be avoided by not exchanging the boundary conditions in every iteration step.


Participating media, radiative transfer equation, iteration, FCC grid, diffusion solution, Scalable Visualization Array