Ok, to start with I have a skeletal mesh, with 5 bones. One root bone, and four childed bones. I’ll call them tassel bones, since they are meant to flop around. When I import the mesh from scratch, everything looks good, the skeleton shows the bones in the right position, and if I go to the default physics actor and simulate, everything works like it should at default settings.
The problem happens if I take the root bone, and set it to kinetic, so that it will remain stationary. Now, when I click simulate, all tassels but the first one in the bones list will have its transform changed. It seems as if their relative transform was scaled down to .3937.
So in the case that I set them all to be hinge joints so they flop in one axis, but should not move, it will suddenly move to this location and simulate from there.
Note that the actual bone scale does not change, just the location.
I tried importing it with a different default scale, and at a scale of .3937 import uniform scale, everything kept working fine, the first bone and all the others. On the other hand at import scale of 10 tassels 2, 3, and 4 were extremely close to the center, so it’s not just their relative transform changing to .3937 of the imported scale, but to an absolute value of .3937 in place of the imported scale.
For the record I am using 3dsmax 2015 for making the assets in this case (yes, even if the import says 2014), and this issue happens regardless of “convert scene unit” being checked on import or not.
So while I did sort of find a workaround of importing at scale .3937, I’d like to know what’s going on if possible. I’m guessing I’m missing something obvious, since I’ve worked on stuff in the past without doing that and had things work fine in similar situations.
[Zip of the example model used here][4]