Help! Custom joint mapping for motion capture


I have been trying for days to find an answer to this question. I have spent many hours trying different things, working my way through HIK, etc.

I have a character to rig. The plan is to do motion capture, then bring this into Maya and apply it to my character. The character is a robot. Due to his design, none of his joints can have more than one degree of rotation. Thus, I have a bone that will swing his arm (shoulder y rotation) another to lift his arm (shoulder z rotation) and then a roll bone in the upper arm to turn the arm (shoulder x rotation).

I can’t post the character due to IP, but I hope this is clear.

If I pull in a running motion capture clip and map it, using HIK and rotation limits , I can get the legs just about there, but the arms are a disaster. As I said, I split the rotation into three bones, but how do I then map the rotations from the single joint/bone of the mocap character?

I could try to do it with expressions for each bone, but, talk about time consuming and hard to update with any changes. And how would I then bake it out to keys?

Any help or tutorials or anything someone can point me to?

Here is a screen shot of what I am trying to do.

Or, if there is a better way, any suggestions are welcome.

I present to you our animation studio