OK, never used sculpt (other than just to bake map), so not exactly sure how that works, but guessing it fits the desc of object being modified, so displacements can be mapped onto unmodified base object.
In my case, I have 2 separate objects One is base smooth mesh. The other is 4x sub of that base mesh which is then deformed after sub applied, so I can’t just get from one to the other by applying sub, and sculpt tag method doesn’t seem to allow choosing a separate object as the bake target… only subdivided version of itself.
Will take another look at BM. Did you select tan option somewhere that I missed? Which type of displacementmap did you feed it from c4d? Object, tangent, world, intensity, etc)? If it’s just spitting out normal map that matches the type of displacement map that was input, then…
If I understand correctly, burning a tangent displacement map from c4d won’t work for me for the same reason… because the high and low poly are two separate objects, and attempting to bake from the high poly yields zero tangential displacement since it is… itself.