10.2312/SRE.20181173
An Improved Multiple Importance Sampling Heuristic for Density Estimates in Light Transport Simulations
Jendersie, Johannes
Grosch, Thorsten
The Eurographics Association
2018
978-3-03868-068-0
1727-3463
https://diglib.eg.org/bitstream/handle/10.2312/sre.20181173/065-072.pdf
8 pages
Vertex connection and merging (VCM) is one of the most robust light transport simulation algorithms developed so far. It combines bidirectional path tracing with photon mapping using multiple importance sampling (MIS). However, there are scene setups where the current weight computation is not optimal. If different merge events on a single path have roughly the same likelihood to be found, but different photon densities, this leads to high variance samples. We show how to improve the heuristic for density estimation events to overcome this issue by including the photon density into the MIS computation. This leads to a faster convergence in VCM and related techniques. The proposed change is easy to implement and is orthogonal to other improvements of the algorithm.
Eurographics Symposium on Rendering - Experimental Ideas & Implementations
Rendering Techniques II
65
72
Johannes Jendersie and Thorsten Grosch
CCS Concepts: Computing methodologies --> Ray tracing; Mathematics of computing --> Sequential Monte Carlo methods
Computing methodologies
Ray tracing
Mathematics of computing
Sequential Monte Carlo methods
Paper
065-072