ReSTIR FG: Real-Time Reservoir Resampled Photon Final Gathering
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Date
2024
Authors
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Journal ISSN
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Publisher
The Eurographics Association
Abstract
Achieving real-time global illumination for a given scene remains challenging, even with the advent of hardware ray tracing, due to the substantial quantity of rays required. To enhance the quality of the limited number of samples, spatial and temporal resampling can be used. The concept of resampling gained popularity with ReSTIR DI [BWP*20], enabling real-time direct illumination for scenes with millions of lights. This concept was further extended by combining it with path tracing to quickly approximate the indirect illumination (ReSTIR GI [OLK*21]) or correctly approximate global illumination (ReSTIR PT [LKB*22] and Suffix ReSTIR [KLR*23]). However, these algorithms fall short in effectively rendering caustic effects -bundles of reflected or refracted light- often associated with photon mapping. We introduce ReSTIR FG, an efficient real time indirect illumination algorithm that combines photon final gathering with the principles of ReSTIR. First, we introduce an efficient photon final gathering scheme, enabling quick consistent offline rendering. Then we combine our photon final gathering with spatiotemporal resampling to allow for real time global illumination. Our algorithm is capable of displaying multi bounce indirect illumination, as well as caustic effects, while remaining competitive in both runtime and quality when compared to the aforementioned state-of-the-art global illumination resampling techniques.
Description
CCS Concepts: Computing methodologies -> Rendering; Ray tracing
@inproceedings{10.2312:sr.20241155,
booktitle = {Eurographics Symposium on Rendering},
editor = {Haines, Eric and Garces, Elena},
title = {{ReSTIR FG: Real-Time Reservoir Resampled Photon Final Gathering}},
author = {Kern, René and Brüll, Felix and Grosch, Thorsten},
year = {2024},
publisher = {The Eurographics Association},
ISSN = {1727-3463},
ISBN = {978-3-03868-262-2},
DOI = {10.2312/sr.20241155}
}