At the start of a clip, the talent’s head that I’m roto’ing is in a neutral position, but then tilts there head away from the camera over time, and I need to then pull in my roto shape on their head at the end of the clip to account for this. Is there some standard/common or better way for me to keep my roto locked to the edge of my subject during this kind of movement?
Well, if I understand what you are asking correctly, for shapes like ears and nose, you can just make separate shapes to handle where they cross edges. Then it becomes easy to animate the edge of the head and only worry about keyframing shapes where they cross the line.
All current spline roto techniques coupled with tracking is going to demand a little bit of hand correction to follow the edge exactly.
Ah ok, thanks for the tips/insight Mary, I’ll try adding a few more shapes in on the head.