I'm trying to use Blender to create a custom emote for Sansar. I've downloaded the Sansar reference model and I have a BVH mocap file that I'm trying to apply to it.
I wasn't able to figure out how to apply the BVH to the Sansar armature directly, so I'm trying to use Bone Constraints to make the Sansar model follow the animation. For the left side this was easy, as the Sansar model uses similar bones to those in my BVH file.
But I'm having much more trouble on the right hand side of the body. This is because the Sansar model seems to have the rotation for all the bones on the right hand side inverted:
The Sansar model has the joints in the right places, but then the bone is pointed in the exact opposite direction. For example, the Sansar R_hip joint corresponds with my BVH's "RightUpperLeg" bone, but the Sansar bone then extends into the torso.
I'm not able to change anything about the rigging, since then my emote wouldn't be compatible with any other avatars on Sansar.
I'm using the "Copy Rotation" constraint, but for all the limbs on the right hand side of the model this leaves them grotesquely contorted. I've tried using the "Invert" options on the "Copy Rotation" constraint, but this doesn't seem to do what I expected, only rotating the bones slightly instead of a full 180 degrees. I'm wondering if maybe the "Invert" options only work in local space, not world space? Or maybe I'm misunderstanding what they are inverting.
I tried rotating the bones manually in Pose mode, but this didn't have any effect. I think my rotation is being overridden by the constraint.
Is there a way that I can apply a rotation to these bones AFTER the constraint is resolved?