My video is shot from a moving head cam. I have placed a cartoon character on the edge of a piste using Track layer and in front of it is a sign that i have traced using Drivex shape mask. That works fine and the sign travels across the cartoon masking as required. A skier then enters the shot and travels past the cartoon and the sign. I add another shape mask. I cannot get both masks to work together as one puts an image in where the other is taking it out. Is it possible to mask two objects? If so how. Thanks for your help. KK
Why are you using DriveX to do a simple shape mask? It's really meant to do other things, complex effects. You don't need a plugin to do masking in Motion. Or are you working in FCPX? In which case TrackX is probably what you want to use.
Can you post the video for us to see?
Off the bat, I'd say you need to put the skier, who appears in front, as the very top layer.