I created an animation in which a Bezier spline is animated to interact with an actor. The source footage we had was reshot, so the timing of the animation and placement of the control points is no longer in sync with the footage. I am able to move the existing keyframes around, but for some reason, I am unable to duplicate an existing keyframe such that the control points freeze in place for several frames before the next keyframe where the control points are moved. Whenever I select a keyframe and copy/paste it using the command-c/command-v shortcuts, the new keyframe is created almost the same way as when the new keyframe button is pressed. Is there no way to duplicate control point keyframes in Motion? The only options I can see right now are to tediously copy every control point's x and y position individually, to redo the animation in Motion, or to redo the animation in a different application. None of those options are particularly viable given the project's schedule.
One theory I have is that Motion does not save control point location, but control point displacement in its keyframes. If this is the case, is there an easy way to make a zero-displacement keyframe? Making a keyframe on the first frame and pasting it after another keyframe does not work.
I no longer need help with this problem (I ended up reanimating a significant part of the animation (a whiteboard sequence explaining the Doppler effect), which is now available for viewing on Vimeo at http://www.vimeo.com/18164007). If anyone has an answer, though, I am sure that it would help me (and other artists) in the future.