Personal tools
You are here: Home Publications Temporal Gradient-domain Path Tracing

Temporal Gradient-Domain Path Tracing

ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia 2016)

tgpt

Marco Manzi*
Markus Kettunen*
Fr├ędo Durand Matthias Zwicker
Jaakko Lehtinen
 University of Bern
Aalto University
Massachusetts Institute of Technology
University of Bern
Aalto University, NVIDIA

*These two authors contributed equally to this work

Abstract

We present a novel approach to improve temporal coherence in Monte Carlo renderings of animation sequences. Unlike other approaches that exploit temporal coherence in a post-process, our technique does so already during sampling. Building on previous gradient-domain rendering techniques that sample finite differences over the image plane, we introduce temporal finite differences and formulate a corresponding 3D spatio-temporal screened Poisson reconstruction problem that is solved over windowed batches of several frames simultaneously. We further extend our approach to include second order, mixed spatio-temporal differences, an improved technique to compute temporal differences exploiting motion vectors, and adaptive sampling. Our algorithm can be built on a gradient-domain path tracer without large modifications. In particular, we do not require the ability to evaluate animation paths over multiple frames. We demonstrate that our approach effectively reduces temporal flickering in animation sequences,  significantly improving the visual quality compared to both path tracing and gradient-domain rendering of individual frames. 

Materials

publication, slides, video (uncompressed, youtubevimeo)

Code

We provide code based on  Mitsuba renderer that implements temporal gradient-domain path tracing. We also provide some example scenes and configurations from the paper to test the code.

code repository, scenes

Document Actions