Time Dependent Photon Mapping

Mike Cammarano
Henrik Wann Jensen

Stanford University

Without motion blur animations show strobing artifacts.
Our new time dependent radiance estimate enables
motion blurred global illumination such as this
motion blurred caustic.


The photon map technique for global illumination does not specifically address animated scenes. In particular, prior work has not considered the problem of temporal sampling (motion blur) while using the photon map. In this paper we examine several approaches for simulating motion blur with the photon map. In particular we show that a distribution of photons in time combined with the standard photon map radiance estimate is incorrect, and we introduce a simple generalization that correctly handles photons distributed in both time and space. Our results demonstrate that this time dependent photon map extension allows fast and correct estimates of motion-blurred illumination including motion-blurred caustics.

Mike Cammarano and Henrik Wann Jensen.
"Time Dependent Photon Mapping".
Proceedings of the 13th Eurographics Workshop on Rendering, Pisa, Italy, June 2002

time_photon.pdf (1.2MB)