Hi, I spent my day try to resolve this twisting skinning issue but didn't solve it.
My tail bones are not twisting as you can see, the Z axe is always up. The deform bones have copy transform constraints on bones which have "damped track" and "stretch to" constraints. If I disable the constraints and move manually the def bone of my tail base, it's ok but since I activate the constraints the skin twitst but not the bone. I exported it with the twist skinning issue to see what happends in unity.And surpris! In unity the skinning is fine. So I re-import my fbx on blender et as in unity the skinning is correct too.
So I deduce that blender misscalculate the skinning of def bones sometimes because of the constraints : the bones have correct rotations but the skinning dont get it, or I miss something ? Is someone can help me tu understand please ?
P.S: the twist skinning happens only in a short range of rotation, I think it's linked to the damped track solving P.S2: sorry for my bad english