How do I crop images for a 4 corner match move?

Question

I have a picture frame in my video that I would like to show images on and I want to animate some zooming and panning.  The parts of the images that are out of frame need to be cropped obviously.  I'm not sure how to do this.  There is a crop property, but that is extremely inconvenient to use.  I just want to define a view rectangle such that everything outside of the rectangle does not show up in the picture frame.  This rectangle needs to be compatible with match move so that I can attach it to the picture frame.

Answer 1

Here's the setup I would suggest.  Since you are trying to match a picture frame, which tend to be standardized in size (8x10, 4x6, etc.) you just need to create a 2D group that matchs the appropriate dimensions.
-Create a 2D group, make sure it is nested inside the default group.
-Select the group in the Inspector>Group settings, make it 2D/Fixed Res, and then set the width and hight as needed (400x600 for a 4x6 frame).  This way you don't have to worry about cropping, it's done for you by the group.
-Animate your stills inside the group as needed.
-Apply the analyze motion behavior to the clip you need to track and track.  Make sure you set the trackers in a clockwise patern starting from the top left. This will simplify the setup going forward.
-Now, apply a Match Move behavior to the Fixed Res 2D group, set it to 4 Corner and in the "To" pop up, select the analzye motion behavior. Make sure the track pop-ups go clockwise, top left to bottom right.
-Draw a rectangle mask on the picture frame clip.  Apply the Shape Track behavior to mask and again, reference the Analyze Motion behavior. Again, make sure the tracks to clockwise.
-Put the picture layer underneath the frame layer.  This way you can adjust the corner points if needed and make the "images" larger or smaller to fit if needed.
You will problably want to use the Mimic source setting so you can adjust the corner points for the mask or 2D group if needed.  If you are doing complex or 3D efffects with the pictures in the frame, I would mabye set these up in their own project and then render them out as a QT movie. Same idea applies, just make sure your canvas size is roughly the same ratio (8x10, etc.) as the picture frame you are trying to match to.