Errors And Corrective Actions

Fails to indentify target rig automatically

The most common problem is probably that the BVH Retargeter fails to identify the target rig automatically. There are several possible reasons for this:
  • The character is not oriented correctly. In the rest pose, the character should be standing with up being the positive Z axis and facing -Y.
  • The armature is complex with extra bones not corresponding to a standard biped rig.
  • The armature only has IK arms or legs. The BVH Retargeter retargets animations to the FK limbs, so if no such bones exist, the program will not work.
mwa-110-reverse-hip
It is rather common that an armature has a reverse hip. In a normal hip setup, the armature root is the hip or pelvis bone, and the thighs and the rest of the spine are children of this bone. In a reverse hip setup, the first bone in the spine has been reversed. There is a separate root bone, and the two lowest bones in the spine are both children of thise root, whereas the thighs are children of the reversed hip.
mwa-120-reversehip
The advantage of such a setup is that the upper and lower body can be posed independently. However, the BVH Retargeter fails to identify the bones, unless the Reverse Hip option has been enabled.

If automatic bone identification still fails, bone mapping has to be made manually. How this is done is described in this document.