Problems pasting masks in After Effects

I am able to track objects fine in Mocha Pro and they look perfect when I play the tracks, but when I export into After Effects (File-Export Shape Data-Copy to clipboard (as mocha shape data for AE) several problems arise:

  • If I use the “paste” function, the track stays on the object for the most part, but the edges jump around and does not play at all like it does in Mocha Pro. It’s almost like AE is only reading the keyframes and not the actual tracking data, trying to guess to motion in between even though it should already be there.

  • If I use the “paste as mocha mask” function, the mask is off by about 50 pixels to the left and I cannot find any way to slide it over.

I am using the same frame rate and film type/pixel aspect ratio and I can’t figure out how to get these masks to line up.

Are you pasting in on the first frame? And are you sure the frame rate and aspect ratio is the same from the footage settings to the comp settings to mocha? Can you triple check? If your footage interpretation is 24 fps in a 23.976 cop, the frames are not going to line up, even if the settings in mocha are 23.976, for example.

Thanks for your help! I think there was something wrong with the video file because all of the settings were exactly the same for mocha/video/AE composition but there were so many issues exporting a working mask. I pulled the raw footage and encoded a new video and everything is working fine now.


I am wondering though what the major differences are between the regular paste function and paste as Mocha mask. I have gone through the basics of Mocha videos and the Lynda course, but I don’t think this was discussed much in either.

The main difference is that pasting in with just “paste” gives you a black and white matte via a plugin and respects any edge feathering you have done in mocha, the “paste mocha mask” function gives you a lightweight spline that does not respect edge feathering. When you have 100+ shapes, pasting them in as splines instead of as effects takes much less time to render.

I had previously been using the regular paste function because for some reason, paste as mocha mask wasn’t lining up with my videos. I’ve started using a different encoding method and now that “paste as mocha mask” works, I am in awe that my 50+ layer composition in After Effects is rendering in realtime on a Macbook Air. Amazing. Thanks for the great software!

Happy to help!