Stochastic Substitute Trees for Real-Time Global Illumination

Wolfgang Tatzgern, Benedikt Mayr, Bernhard Kerbl, Markus Steinberger

Research output: Contribution to conferencePaperpeer-review


With the introduction of hardware-supported ray tracing and deep learning for denoising, computer graphics has made a considerable step toward real-time global illumination. In this work, we present an alternative global illumination method: The stochastic substitute tree (SST), a hierarchical structure inspired by lightcuts with light probability distributions as inner nodes. Our approach distributes virtual point lights (VPLs) in every frame and efficiently constructs the SST over those lights by clustering according to Morton codes. Global illumination is approximated by sampling the SST and considers the BRDF at the hit location as well as the SST nodes' intensities for importance sampling directly from inner nodes of the tree. To remove the introduced Monte Carlo noise, we use a recurrent autoencoder. In combination with temporal filtering, we deliver real-time global illumination for complex scenes with challenging light distributions.

Original languageEnglish
Publication statusPublished - 5 May 2020
Event2020 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games: I3D 2020 - Virtual, San Francisco, United States
Duration: 15 Sept 202017 Sept 2020


Conference2020 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games
Country/TerritoryUnited States
CityVirtual, San Francisco


  • Global illumination
  • many lights
  • ray tracing
  • real-time

ASJC Scopus subject areas

  • Human-Computer Interaction
  • Computer Graphics and Computer-Aided Design

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