Coherent Out-of-Core Point-Based Global Illumination

Janne Kontkanen
janne.kontkanen@gmail.com
Eric Tabellion
et@pdi.com
Ryan S. Overbeck
roverbeck@gmail.com

PDI/DreamWorks


The Paper: OutOfCorePBGI.pdf

Auxiliary Material: AuxiliaryMaterial.pdf

Abstract:

We describe a new technique for coherent out-of-core point-based global illumination and ambient occlusion. Point-based global illumination (PBGI) is used in production to render tremendously complex scenes, so in-core storage of point and octree data structures quickly becomes a problem. However, a simple out-of-core extension of a classical top-down octree building algorithm would be extremely inefficient due to large amount of I/O required. Our method extends previous PBGI algorithms with an out-of-core technique that uses minimal I/O and stores data on disk compactly and in coherent chunks for later access during shading. Using properties of a space-filling Z-curve, we are able to preprocess the data in two passes: an external 1D-sort and an octree construction pass.

Published at Eurographics Symposium on Rendering 2011.


June 15th, 2011