I have been trying to get my mask tracking working right. I wanted to put a mask with flames showing through in a window of a building where there is supposed to be a fire. I figured out to get the mask to work but the camera is shakey and then someone walks by and the camera follows them so the window frame moves across the scene as the camera pans. My problem is that the flames don't want to stay in the widow. My mask is jumping around all over the place. How can I get it to follow the window frame through the scene so the flames are always in the proper relative position?