Eurographics Digital Library now runs dspace7. Some settings need to be completed in the next few days. Please report any problems to eg-support@eg.org. (The old server is still available at https://dlold.eg.org/ )
(The Eurographics Association, 2018) Jendersie, Johannes; Grosch, Thorsten; Jakob, Wenzel and Hachisuka, Toshiya
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.