Metropolis Photon Sampling
  ShaoHua Fan     Stephen Chenney     Yu-Chi Lai  
Shaohua Fan, Stephen Chenney and Yu-Chi Lai, "Metropolis Photon Sampling with Optional User Guidance" , Eurographics Symposium on Rendering, 2005, pp. 127-138.

We present Metropolis Photon Sampling (MPS), a visual importance-driven algorithm for populating photon maps. Photon Mapping and other particle tracing algorithms fail if the photons are poorly distributed. Our approach samples light transport paths that join a light to the eye, which accounts for the viewer in the sampling process and provides information to improve photon storage. Paths are sampled with a Metropolis-Hastings algorithm that exploits coherence among important light paths. We also present a technique for including user selected paths in the sampling process without introducing bias. This allows a user to provide hints about important paths or reduce variance in specific parts of the image. We demonstrate MPS with a range of scenes and show quantitative improvements in error over standard Photon Mapping and Metropolis Light Transport.


@inproceedings{fan05, author = {Shaohua Fan and Stephen Chenney and Yu-chi Lai},

title = {Metropolis Photon Sampling with Optional User Guidance},

booktitle = {Rendering Techniques '05 (Proceedings of the 16th Eurographics Symposium on Rendering)},

pages = {127--138},

year = {2005} }