Hmm, almost said it all right there. I have a MEDIUM WIDE SHOT TILT UP from the street to a building. Along the top of the building, which is not visible in the begining of the shot, is a sign I need to blur out. I would like to use the Paint effect and Motion Tracking to do this. I know if the sign were in the frame at the begining of the shot and out of it at the end I could draw my blur area over the first frame and then set my Motion Tracker to some other point that will stay in for the duration. Is there a way to do the inverse and blur the last frame and somehow track backwards?
I've already thought of and chosen not to go with the following:
1. Put a -100% Motion Effect on the shot, apply the blur to what is now the first frame, run Motion Tracker, render, export, reimport as a new file.
2. Apply an Add Edit immediately before the sign comes on screen and start the blur just off screen where it's coming from.
Any other ideas though would be welcome.