I have gathered some performance data for the calculation of the intersecting volume between an elliptical cross-section cylinder (tgc) and a hexahedron (arb8) using gqa in MGED. I created a 100x scaled version of the same model and again used gqa to calculate the volume. I used the following command to get the volume and time (time "gqa ..."):
gqa -Av -g XX int.c
where XX is the grid spacing I used except for the default case.
I see that the default 0.25 lower limit for the grid size is not optimal for either the original or the 100x scaled version of the model. Also, I can get to within 0.3% error in 0.05s for the small model but for the 100x model requires more than 0.15s to get to the same error level. Here is the data in a table (hoping the formatting will stay as it is)
Grid Size (% of charc. Size)
Def. Grid Size (0.25 abs lower limit)
I also need to calculate the center of gravity for the combination but I can't seem to find out how to assign the density and then get the center of gravity/moments of inertia information.
Any help with the volume calculation accuracy and speed as well as the density assignment and center of gravity calculations is much appreciated.