Mapping two joints to the same node - mecanim.

I am working on a rather long-term project. Recently we decided to make the switch to Unity’s mecanim which has made some things much easier. Unfortunately, we created several hundred animation assets before this switch, and we’ve run up against an interesting dilemma.

Our character’s spines have 5 joints. spine01, spine02 and so on. Mecanim only allows the mapping of 3 spine joints (including the hips) for retargeting. Does anyone know of a way to either allow mecanim to utilize one or more missing joints, or allow us to map the average of two spine joints to one mecanim “slot?”

We’re using Maya/FBX to author assets.

Hi - Mecanim re-targeting should handle this - spine rotation will be redistributed from 5 joint to 3 joint. Obviously you won’t get exactly the same pose but the chest position will match the original source.

A workaround might be to create a 3 joint rig in Maya and use the Maya Human IK to re-target the motion from the original as you will have more controls over the bones there. I would imagine this process could also be automated/batched for your models with a Mel Script.