Ae screws mask for 15 frames then fits perfectly again

hello …
i’m working on a project that requires to erase the background of whole movie scenes, time consuming work, lots of long distance shots in there, lots of moving body parts
i’ve erased the background of a clip with 400 frames, looks perfect in mocha so i import the masks to ae and apply those to the clip which gets me one particular mask that wanders off just to jump back in place after 15 frames, it’s motion not shown in mocha, all other masks fit perfectly. i’ve no idea what causes this hickup. one time mocha crashed while i was working on this very project, afterwards mocha wasn’t able to restore all masks (lost four of 85 masks), mocha did list all masks in the layer control window but these four masks weren’t actually shown in my clip window. might this crash have caused my weird mask hickup? any ideas how i might be able to get the actual masks shown in mocha without any changes into my ae project?
so long
juergen

hello martin
thanks for your quick reply, i’ve bypassed the problem, i dublicated the layer unlinked the shape layer from the tracking layer and covered the screwed up parts with shapes frame by frame …
i don’t want to send the file cause it’s an uncompressed clip but thanks for the offer.
what i’d like to know if this is a common issue and how to prevent it?
sorry for being vague in my first post…
juergen

oh, i might reconsider your suggestion but i’m not at university right now, have to check on the file size of the mocha project, could be 45 mb…
as i said in mocha everything looks fine, all the shapes fit as i intended, the tracking layer is defenitly far from perfect but there are a lot of keyframes to fix the inacurate track…
i’ll let you know if i decide to send the mocha project
juergen

well then it’s just a matter of time : )

martin
i need to apologise …i’ve never sent you anything… sry
looks like my layer names caused the loss of shape information …
mocha for ae … seems to have difficulty coping with names like:
“body garbage roto 4.1.1.”
it’s the three digits i think … e.g. “body garbage roto 4” works fine…
so long
juergen

I meant the mocha file, not the footage (I can test with my own footage), sorry, I should have been clearer.
No, this is not common. Normally a shape can be thrown if the object you have tracked has made the tracking surface too large and rotated beyond the camera. If you turn on the blue surface object and it’s twisted or going off on strange tangents, this is possibly the case. You can try to fix it using Align Surface to pull the surface object back into place.

Hi juergen, i’d have to see the file, but it could be that the tracking for one shape is being thrown off and causing problems when it’s exported.
A crash could corrupt the mocha file to make the missing layers occur.
If you want me to take a look at it, send me the mocha file:
martinb[at] imagineersystems{dot}com.

If you zip the mocha file it will shrink considerably.

Thanks for letting me know Juergen, i’ll test this out.