Mending Broken Arms

In my last post, I said I would discuss motion capture in relation to keyframe animation. Unfortunately, I was not able to complete everything I wanted for this post due to unforeseen complications with the character rigs. I will talk about the things I was able to finish for this week in this post and try to solve the remaining problems in my next post.

A few weeks ago, I spent about 4 days making the following animation clip using keyframe animation. It’s quite stylized and features characters making movements a normal person would not be able to.

I wanted to see if motion capture could do something similar while requiring less time and editing. This week, thanks to Kevin Yang who wore the mocap suit and acted, I was able to record several variations of this animation in about 30 minutes. Kevin, of course, is not a trained stuntman or a superhuman soldier so his movements are slower and not as sharp as the characters in the keyframed animation. But, given the circumstances, he was able to get reasonably close to the movements of the original animation. What you see below is one of Kevin’s takes.

I spent a few minutes cleaning up some of the more obvious issues with the recordings then exported them to be applied to a character. This is where the problems arose. The character I used in my animation has a custom control rig that was made with an external plugin for Maya. This made it very difficult to connect the character to the motion capture data as I had to deal with many more joint and controls than standard Maya skeletons. After about a day, I couldn’t figure out the problem which you can see below. The character’s legs follow the motion capture data correctly but the arms do not.

So for next time, I will continue this work. I will figure out a solution to arm problem then evaluate the motion capture more closely to figure out what can be done to make it more stylized. What I am proposing is fairly close to what we did for the characters in CAVE – taking motion capture and modifying it – but I think it would be nice to have it all documented and to see exactly how much time we are saving vs straight keyframe animation.