Learning to Importance Sample in Primary Sample Space

dc.contributor.authorZheng, Quanen_US
dc.contributor.authorZwicker, Matthiasen_US
dc.contributor.editorAlliez, Pierre and Pellacini, Fabioen_US
dc.date.accessioned2019-05-05T17:39:40Z
dc.date.available2019-05-05T17:39:40Z
dc.date.issued2019
dc.description.abstractImportance sampling is one of the most widely used variance reduction strategies in Monte Carlo rendering. We propose a novel importance sampling technique that uses a neural network to learn how to sample from a desired density represented by a set of samples. Our approach considers an existing Monte Carlo rendering algorithm as a black box. During a scene-dependent training phase, we learn to generate samples with a desired density in the primary sample space of the renderer using maximum likelihood estimation. We leverage a recent neural network architecture that was designed to represent real-valued non-volume preserving (''Real NVP'') transformations in high dimensional spaces. We use Real NVP to non-linearly warp primary sample space and obtain desired densities. In addition, Real NVP efficiently computes the determinant of the Jacobian of the warp, which is required to implement the change of integration variables implied by the warp. A main advantage of our approach is that it is agnostic of underlying light transport effects, and can be combined with an existing rendering technique by treating it as a black box. We show that our approach leads to effective variance reduction in several practical scenarios.en_US
dc.description.number2
dc.description.sectionheadersSampling
dc.description.seriesinformationComputer Graphics Forum
dc.description.volume38
dc.identifier.doi10.1111/cgf.13628
dc.identifier.issn1467-8659
dc.identifier.pages169-179
dc.identifier.urihttps://doi.org/10.1111/cgf.13628
dc.identifier.urihttps://diglib.eg.org:443/handle/10.1111/cgf13628
dc.publisherThe Eurographics Association and John Wiley & Sons Ltd.en_US
dc.subjectComputing methodologies
dc.subjectRay tracing
dc.subjectNeural networks
dc.subjectImportance sampling
dc.subjectGlobal illumination
dc.titleLearning to Importance Sample in Primary Sample Spaceen_US
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