Mocap walks in Motionbuilder that bounce
Hi, Whenever I work on motion capture walk cycles I find that I always need to "fix" them, the main issue for me is too much hip bounce. Even when the mocap data looks perfect on the Actor, it doesn't look the same once it is on the Character's rig - it acquires a certain extra hip bounce. Ive used mocap walks captured from different people, and yet every time that peculiar bounce creeps in at the Actor-to-Character step. What's going on?
I realize that all mocap requires hand keying to really look nice, but what bugs me is that the results I seek are sitting right in front of me in the Actor's motion and I am baffled by why I cannot get that exact motion onto my Character. Recently, I've been using the sliders in the CharacterSettings pane to remove the bounce, but doing so also effects other aspects of the motion, such as side-to-side motion, or dampening it to the point of killing most of the spine/neck/head play. One slider I found to be particularly effective at removing the bounce is HipsPull with a value at about 60+, this basically forces the hips to ride high so that the dip in the walk cycle gets minimized. It sort of works, but I'm really more interested in avoiding the causes of the issue. I would like to preserve the mocap since I like the mocap fine, but I dont like the way it looks once its on the Character. I would like to avoid re-creating my mocap by hand key-framing, I want to change mocap as little as possible.
I have tried a few variations on the skeletal structure of the hip, I started with the traditional upsidedown "Y", I've tried the upsidedown "T", and I've also tried a "dingle" version that connects the legs to the second spine (bypassing the hips) with the hope that I could drop the dingle into the HipsTranslation field of the CharacterDefinitions pane, but no luck. I have yet to discover what this field actually does.
I used to be concerned that my bone placement was to blame, or that my weighting was poorly distributed around the hips. So I tried out a few pre-rigged characters that come from Maya , Cinema & Motionbuilder, hoping that I could find a good example, no luck, they all move with the same characteristic bounce. I'm assuming these are good examples of bone placement and weighting, but maybe they aren't.
Anybody got a tip?