Cleaning up motion data using a control rig

Raw motion capture data often has artifacts when mapped to a character model, such as self-intersections, floating or sinking feet, and sliding contacts with the floor. These notes assume that we have already setup an actor and character.

Post-processing using a control rig

From the character controls window, make sure character is selected. Currently, the input should be 'Actor Input'.

Now, you can edit poses using the control rig effectors. For example, suppose an arm passes through the torso. We can go to the worst intersecting frame, select the hand effector, and drag the hand out of the body. Effectors can be selected from character control pane.

When you are happy with a pose, select whether you want the whole body to be keyed, or just the selected body part. Then choose 'flat' key. Make sure keys are on their own animation layer, so that the raw animation from the motion data is not changed.

NOTE: In the character settings (tab next to character definition), you can specify that you want contacts to be clamped to the floor.

When you are happy with the animation, plot the animation to the SKELETON (Edit, plot Motion, skeleton). It's important to plot to the skeleton to ensure that

Other tips can be found here from mocappys MotionBuilder tutorials.

Fixing foot sliding

Now that we have a control rig setup, we can add additional constraints to prevent effectors from sliding when they shouldn't. Make sure story mode is turned off.

These following notes are based from this video tutorial.

Tweaking FCurves

Joints can be selected in the hierarchy view and edited directly in the FCurves window.

For more tips, check out mocappys.