Temporally Coherent Irradiance Caching for High Quality Animation Rendering
Miloslaw Smyk, Shin-ichi Kinuwaki, Roman Durikovic, Karol Myszkowski

MPI Informatik, Saarbrucken, Germany
Szczecin University of Technology, Poland
The University of Aizu, Japan
Faculty of Natural Sciences, University of Saint Cyril and Metod, Trnava, Slovakia



　Abstract
　In rendering of high quality animations that include global illumination, the final gathering and irradiance caching are considered standard procedures. However, the computational cost they incur is high enough to discourage their wide use in production rendering.

　We introduce a data structure called anchor, which lets us permanently link cache locations to points intersected by their final gathering rays. Consequently, we can cheaply probe and transfer the (ir)radiance by exploiting the temporal coherence of successive animation frames, resulting in half an order of magnitude acceleration and reduced temporal artifacts. Additionally, our anchor structure lets us render moderately glossy surfaces at the cost much lower than the traditional importance sampling techniques. We also describe an efficient, perceptually motivated and independent scheme for limiting the growth in the number of irradiance caches. Finally, an implementation in practical rendering system is demonstrated.
　Anchor
　Detail is described in Section 3, "Anchor Data Structure".
Anchor can be shared by several irradiance caches and
its visibility can be kept in temporal domain

　Sample source code for anchor and irradiancecache class.
　New Animation Framework based on Anchor and Extended Irradiance Cache
　Detail is described in Section 4.2, "Cache Update for the Animation".
　　
　Efficient Cache Management
　Detail is described in Section 4.3, "Cache Density Control"
All cache positions (black dot) unimportant cache positions (red dot)
　Glossy Surface Extension
　Detail is described in Section 5, "Rendering Moderately Glossy Surfaces"
Anchor bucketing using simple reprojection scheme
　Result
　Detail is described in Section 6, "Result"
　Also, you can see more details to download videos under this page.
Sponza Atrium (speed up x5.7) Sibenk Atrium (speed up x5.3) Glossy Cornell (speed up x2.4)
　Videos

　Here you can see some videos:
　Reference
　・Temporary Coherent Irradiance Caching for High Quality Animation Rendering
　　Miloslaw Smyk, Shin-ichi Kinuwaki, Roman Durikovic, Karol Myszkowski
　　To appear in: Proc. of EUROGRAPHICS '05 (Computer Graphics Forum, vol. 24), 2005.
　　(pdf)(slide)(bib)