Jaroslav Křivánek

Adaptive Environment Sampling on CPU and GPU

Asen Atanasov
Chaos Group
Vladimir Koylazov
Chaos Group
Blagovest Taskov
Chaos Group

Alexander Soklev
Chaos Group
Vassillen Chizov
IMPRS, Saarland University
Jaroslav Křivánek
Render Legion
Charles University, Prague


teaser

"Office" and "Living room" scenes rendered with classical environment sampling (Baseline) and our adaptive strategy. We present both CPU and GPU implementation results and show that our algorithm produces much cleaner images in the same time. The effective speedup, measured as the time to achieve the same noise level, for CPU/GPU implementations is, respectively: "Office" - 6.6/3.8 and "Living room" - 2.7/2.4. "Office" scene courtesy of Evermotion.


Abstract

We present a production-ready approach for efficient environment light sampling which takes visibility into account. During a brief learning phase we cache visibility information in the camera space. The cache is then used to adapt the environment sampling strategy during the final rendering. Unlike existing approaches that account for visibility, our algorithm uses a small amount of memory, provides a lightweight sampling procedure that benefits even unoccluded scenes and, importantly, requires no additional artist care, such as manual setting of portals or other scene-specific adjustments. The technique is unbiased, simple to implement and integrate into a render engine. Its modest memory requirements and simplicity enable efficient CPU and GPU implementations that significantly improve the render times, especially in complex production scenes.


Reference

Asen Atanasov, Vladimir Koylazov, Blagovest Taskov, Alexander Soklev, Vassillen Chizov, and Jaroslav Křivánek:
Adaptive Environment Sampling on CPU and GPU. ACM SIGGRAPH 2018 Talks, 2018
DOI | BibTeX


Links and Downloads

paper
supplemental
document
V-ray Next
pdf (1 MB) pdf (6 MB) V-ray Next implements the method as described in the paper

Acknowledgments

The HDR image "Hallway" and the HDR images "Day", "Sunset" and "Night" were kindly provided by Wouter Wynen (Aversis 3D), and Peter Sinitra and Marek Denko (NoEmotion), respectively.