So I have an unusual deformer that requires me to do the normal deformation but also compute an extra output (which is basically some offset values).
When I tried to run it in parallel eval mode I discovered that the inputGeometry (not outputGeometry) was actually being modified during the deform method, so the value contained by inputGeo is different before and after compute. This is a problem for me because the offsets I am computing rely on the inputGeometry. which is incorrect if the ouputGeo is computed first.
I did some testing and this seems to be the case in 2018-2020, and does occur if I do the deformation in the compute method instead of the deform method. This doesn't seem to happen for the default cluster deformer so it seems like it's a bug with MPxDeformerNode not a detail about how parallel eval works.
Has anybody else experience this oddity? Do you know of a workaround?
