The calculation of the photon path is repeated in the forced first scattering code. Once to determine the maximum optical depth along the line-of-sight and a 2nd time to move the photon to the picked scattering site. Code was written by Ka-Hei to do this, but it only worked for a single grid (no hierarchical grids). Need to re-integrate or develop code to do this. A similar issue exists for the next_scatter/scatter_photon functions. Also may want to cache this calculation for the stellar classification in the case of discrete sources.
The calculation of the photon path is repeated in the forced first scattering code. Once to determine the maximum optical depth along the line-of-sight and a 2nd time to move the photon to the picked scattering site. Code was written by Ka-Hei to do this, but it only worked for a single grid (no hierarchical grids). Need to re-integrate or develop code to do this. A similar issue exists for the next_scatter/scatter_photon functions. Also may want to cache this calculation for the stellar classification in the case of discrete sources.