If you track motion in Mocha and want to redo it, do you need to erase the keyframes first, or can you just make your alterations and then redo the tracking? (wasn't sure if that would overwrite old keys so no need to erase)
Mocha updates keyframes just like AE does. No need to erase them. You would only do so, when you accidentally have changed the shape in refinement mode and have messed up your track.
Retrieving data ...