Using hierarchical octrees in Monte Carlo radiative transfer simulations
2013
A crucial aspect of 3D Monte Carlo
radiative transferis the choice of the spatial
gridused to partition the
dustymedium. We critically investigate the use of
octree
gridsin Monte Carlo dust
radiative transfer, with two different
octreeconstruction algorithms (regular and
barycentric subdivision) and three different
octreetraversal algorithms (top-down, neighbour list, and the
bookkeepingmethod). In general, regular
octree
gridsneed higher levels of
subdivisioncompared to the barycentric
gridsfor a fixed maximum cell mass threshold criterion. The total number of
gridcells, however, depends on the geometry of the model. Surprisingly, regular
octree
gridsimulations turn out to be 10 to 20% more efficient in run time than the barycentric
gridsimulations, even for those cases where the latter contain fewer
gridcells than the former. Furthermore, we find that storing neighbour lists for each cell in an
octree, ordered according to decreasing overlap area, is worth the additional memory and implementation overhead: using neighbour lists can cut down the
gridtraversal by 20% compared to the traditional top-down method. In conclusion, the combination of a regular node
subdivisionand the neighbour list method results in the most efficient
octreestructure for Monte Carlo
radiative transfersimulations.
Keywords:
-
Correction
-
Cite
-
Save
0
References
0
Citations
NaN
KQI