I have a 1940's scene in which I'm hiding or replacing some modern elements, an exit sign, a fire alarm box, a modern logo, etc. The frame in the shot I'm concerned with is fairly stable, but two actors are walking toward the camera.
In one shot every good tracking point is obscured at some point by the actors. I need to use at least three succeeding points as the shot progresses. Mocha has problems as well (at least in the small amount of time I've spent with it).
Andrew Kramer's excellent "Set Extensions" tutorial showed me how to join the first two tracking points, but when I move on the the third tracking point I lose the track, and my images start to float around. His tutorial only dealt with two successive tracks.
So to pass the track from the first point (Null 1) to the second (Null 2) I parented Null 1 to Null 2. But with Null 3, do I parent the other two to it, or what?