I am rotoing a clip that is 2 seconds long. The clip is made up of several diffrent shots already edited together. I want to roto the character in the shot, where every few frames he moves abruptly from part of the screen to the other.
I do the usual roto for the whole shot, rotoing the guy in every frame, adjusting the roto shape as i go, but when i go back to see what i have done, the frames between the abrupt jumps are suddenly interpolating the movement of the rotoshape from where he was in one frame (on the right side of the screen) to the next frame (where he is on the far left.) This essentially undoes a lot of work i had just done. So i go back through a second time and realign all the points from where they have been shifted to where they should be, and everything is fine.
How do i stop this from happening? I just want the rotoshape to follow the guy during his abrupt movements from one frame to the next, rather than undoing the points i set and interpolating them. What's going on?
Thanks for your time,