I'm working on a project where I have to fix the way a gun looks in someone's hand. I have to track a hand holding a gun, and then place a replacement firearm over the top. I tracked the hand/gun in a wideshot using Mocha and that worked almost perfectly.
Then I move to the close up. I track the gun in Mocha again -- the tracking appears to work perfectly; the splines move exactly with the gun. When I copy the tracking data over to After Effects, the XY values of the position, the scale, and the rotation all match up with the first tracked frame, but they don't continue to track.
For example, the first tracked frame's XY values are:
Then every single frame after that is
They don't move.
What's going on?
Maybe you exported the tracking data from a wrong layer in mocha?
Also note, that using transform data does not give you shear and perspective data. Therefore, I would use it only for background elements that don't change in perspective. Using a corner pin or doing the replacement in a stabilized precomp might be better.
This tutorial shows various workflows for using mocha:
This one gets you started with stabilized precomps very quickly:
And this one shows how to manipulate also non-flat objects with the stabilized precomps:
Thank you very much for the info.
It turns out I was just being a bit dumb.
I am only trying to track a character's hand movement in part of the shot, not throughout the duration. I forgot to reset my in and out points in Mocha, so when I copy the tracking data, it gives me a ton of stationary points before and after the part I was trying to track. Adjusting my in and out points in Mocha to fit ONLY the part of the shot I was trying to track was my solution.