thanks for the reply & clarification.
You’re correct, I am trying to use a Surface object imported from a DXF file representing a susceptibility iso-surface (created elswhere).
In the GA, it looks like this:
(see if the screenshot uploaded…)
When entering the object (spar_su…etc) into the Reference susceptibility, it offers only the Z for a Value (the Z coord), which is obviously not the correct vallue I want to assign to the surface, but for the testing perhaps good enough.
The inversion procedure gets past the Tiling to Creating Global Octree, Calculating global active cells from topo… then crashes with Index Error: List index out of range.
At this point, rather than creating a function that would be capable of handling just about any surface, I guess a more expedient solution would be to follow a tested and proven path, e.g. using a data format/ object type that’s known to work for the constraint definition.
I haven’t been able to find any demos /tutorials for running the inversion with constraints - anything publicly available?