We introduce a novel photon gathering method to achieve unbiased rendering with photon mapping. We also show that our method can be combined with bidirectional path tracing and Metropolis light transport via multiple importance sampling to achieve unbiased rendering with superior performance over alternative algorithms.

Hao Qin, Zhejiang University
Xin Sun, Microsoft Research Asia
Qiming Hou, Zhejiang University
Baining Guo, Microsoft Research Asia
Kun Zhou, Zhejiang University