Gradient-Domain Bidirectional Path Tracing [article]

Marco Manzi, Markus Kettunen, Miika Aittala, Jaakko Lehtinen, Frédo Durand, Matthias Zwicker
2015 Symposium on Rendering  
Gradient-domain path tracing has recently been introduced as an efficient realistic image synthesis algorithm. This paper introduces a bidirectional gradient-domain sampler that outperforms traditional bidirectional path tracing often by a factor of two to five in terms of squared error at equal render time. It also improves over unidirectional gradient-domain path tracing in challenging visibility conditions, similarly to how conventional bidirectional path tracing improves over its
more » ... nal counterpart. Our algorithm leverages a novel multiple importance sampling technique and an efficient implementation of a high-quality shift mapping suitable for bidirectional path tracing. We demonstrate the versatility of our approach in several challenging light transport scenarios.
doi:10.2312/sre.20151168 fatcat:4j6lexfijbfpjotgzjn3iprgbq