Easy fix for when your Roto track/shape goes WONKY?


So I have a problem that comes up once in a while, where the Talent’s head turns so drastically, from a side profile to basically looking away from the camera, and it ends up throwing my cheek/eye/nose track into limbo at the extreme-away-from-camera frames.

I try to skip the track at these frames and just move the shapes manually, but I get into this situation where some of the edges go waaay of screen and the roto shape ends up twisting.

Is there some guideline or tips I should follow to avoid this from happening, or to fix it when it does show up?


I’m not sure if this is a bug or an inevitable consequence of tracking data that flips too extremely but it is a really common issue.
Only solution I know of is to turn off the shape and make a new one in a new tracked layer which is a bit of an inconvenience.

@persyst I suggest going to the Timeline and removing the Layer’s Transform keyframes on the frames where you are experiencing the issue. Does this solve the problem?

Thanks for this, yes these seems to be the only thing I can do as a workaround.

Hi Marco, it seems even with a deleted keyframe on the layer, the shape still goes wacky when making the shape adjustment. Only drawing and tracking a new shape is the thing that is working for me unfortunately. I was adjusting the forehead shape above the nose shape in this screenshot, which are both part of the same layer. Please let me know if any more incite on this. Thanks again!

Can you send me the project without footage?

Hi Marco, here’s the project. You can see the problem at frame 1339 just for reference, when you open the file. Let me know how it goes. Thanks!!
shape problem demo - frame 1339.sfx.zip (4.8 MB)

You have a bogus shape keyframe for the forehead shape at frame 1339. If you delete that, you should be good to go.

Hi Marco, I put in that shape keyframe just to show how the shape gets skewed at frame 1339. What I’m trying to actually do is stretch the left points of forehead shape further to the Left. Please let me know what you find. Thanks!

Before pulling the points left

After pulling the points left

@persyst I had a look at your project again and the transform really goes crazy at frame 1339. If you select the layer with the Transform tool selected you can see what is happening. So, this is one of those cases where the transform is too extreme.

What did you use to track this?

Got it, yea so the clip starts out with the talent’s face as a side profile, but then at around frame 1339 they look almost completely away from the camera, which ends up squishing the shape, and then the talent returns to a profile view of their face, and then the track is fine again. I guess for that section, do you think maybe retracking those frames but only using X,Y,rotate,scale and unchecking perspective might work, instead of just drawing a new shape for those frame?

Other than the face, the camera motion looks like it is mostly x/y. You could probably just use 1 or 2 point trackers instead of a planar tracker.

Ah oh cool, yea I’ll give the point tracking a go an let you know, thanks!