I am wondering if there is a good way to fill the space with specific cube sizes. I assume this will be something to do with Galapagos or Kangaroo? Thanks in advance!
Do a search for “volume packing” or “volume nesting” or “3D nesting”.
The algorithms are typically used for commercial 3D printing to optimize piece orders for a given build volume (powder layered prints).
This problem is an order of magnitude harder that the 2D nesting case where there are plug-ins like OpenNest.