Tracking Shape Disappears between keyframes

I spent most of a day tracking the way a face moves in a piece of footage… seemed to work great until I got to near the end of the footage. Now suddenly the track shape will fly around in a flickering and crazy pattern between keyframes. I put the footage on a keyframe and the shape is lined up great with an a facial feature… I track forward one frame and the shape completely disappears. Now when I scrub through the footage the shape is flying off into the distance, being stretched weirdly off the page… only on my KEYFRAMES does it sit where it’s supposed to.

It no longer makes any effort to stick to the face the way it does in your tutorials.

The face I’m tracking just moves slowly back and forth. It’s nothing complex.

Yeah, not only is the shape ‘disappearing’… if I go frame by frame is flying all over the place into the gray void around the picture plane… taking on rediculous shapes… flickering, flying from left to right, upper corner. It’s a a glitching mess.

Sorry to spam my own thread, but I have an update as well as a question.

It took a really long time to get the keyframes set to where I want them to be… so I’d rather not spend hours and hours and redoing this shot.

Is there a way to delete the tracking data without deleting the keyframes?.. then I can let it re-track between my key frames?

Because right now whatever it’s done a horrible mess.

When I was originally making the file I was very careful and let the track play as far as it could before it needed to be adjusted with a keyframe. Now all that work is for not?


It sounds like your surface tool is behind the camera. A good way to check this is to turn the surface tool on and see if the surface tool does anything unexpected, like disappear. You may need to re-track the object.

If you using perspective when you track (or sometimes altering the surface tool to far in manual or adjust track), it may be that your surface is going behind the camera in mocha and corrupting the data. In mocha, problem splines can occur when the tracking data has become so skewed it goes off or “behind” camera, the keyframes the tracking data generates can throw the shape information out of order. You may need to re-track the shape using only translation, scale, rotation, and shear instead of perspective. This is especially true for complex roto of an object that is turning away from screen or tracking an object that is turning.

Try retracking those shapes without perspective and trying again.

To fix what you have, go into the dopesheet and twirl your layer down for the layer you want to delete tracking data from. Find the tracking data and delete it but not the shape data. Retrack without perspective. I personally recommend that folks not use perspective for complex organic roto at all.