sppm & mlt & sppm+mlt

i want to implement and reimplement:
stochastic progressive photon mapping
metropolis light transport
hybride stochastic progressive photon mapping with metropolis light transport


document to read: Improved Stochastic Progressive Photon Mapping with Metropolis Sampling
Jiating Chen, Bin Wang, and Jun-Hai Yong

School of Software, Tsinghua University

Computer Graphics Forum, volume 30, Number 4 (Proceedings of the EGSR2011), to appear.