A low-complexity discrete radiosity method

Rather than using Monte Carlo sampling techniques or patch projections to compute radiosity, it is possible to use a discretization of a scene into voxels and perform some discrete geometry calculus to quickly compute visibility information. In such a framework, the radiosity method may be as precise as a patch-based radiosity using hemicube computation for form factors, but it lowers the overall theoretical complexity to an O(NlogN)+O(N)O(NlogN)+O(N), where the O(N)O(N) is largely dominant in practice. Hence, the apparent complexity is linear for time and space, with respect to the number of voxels in the scene. This method does not require the storage of pre-computed form factors, since they are computed on the fly in an efficient way. The algorithm which is described does not use 3D discrete line traversal and is not similar to simple ray tracing. In the present form, the voxel-based radiosity equation assumes the ideal diffuse case and uses solid angles similarly to the hemicube.