🐛 unsupported operation for type hmax_: gradients not yet implemented! in grids3d.cpp code

[vucenovic]

Hello, I was trying to run an optimization with a volume grid, and found that the occurances of "hmax" function in the grids3d.cpp code are not compatible with it yet. I am fine with just commenting out the occurances for now, but how did you run your smoke volume optimization example with this code? Additionally, I am trying to do something similar as the smoke volume optimization and wanted to ask if there is example code for that (scene/python code).