It looks like low-discrepancy sequences (http://en.wikipedia.org/wiki/Low-discrepancy_sequence http://en.wikipedia.org/wiki/Low-discrepancy_sequence) might be a

It looks like low-discrepancy sequences (http://en.wikipedia.org/wiki/Low-discrepancy_sequence http://en.wikipedia.org/wiki/Low-discrepancy_sequence) might be applicable for your quasi-Monte Carlo sampling of the scattering.