Global illumination in sparse voxel octrees

Abstract

This paper enhances the voxel-to-voxel radiance shooting, propagation, and scattering algorithm of Max [20]. It reduces the memory requirements by storing the radiance only on the occupied cells of a sparse voxel octree and by sampling only 24 propagation direction bins instead of 96 or more. It gives a modification of the propagation algorithm to compensate for the larger solid angle of the direction bins and allows for position-dependent fully anisotropic scattering. For a volume of $$n^3$$ n 3 voxels, the computation time is $$O(n^3(\mathrm {log}\,n)^{3/2})$$ O ( n 3 ( log n ) 3 / 2 ) .