Tracking mask shrinking for no reason

I’m trying to track an area on a piece of clothing for a product video. There is a lot of contrast, but even when the model is not moving, the tracking mask seems to just shrink, which means I have to adjust every point fairly regularly. I was hoping the tracking algorithm would do well in this situation, but it seems to be working against me.

Here’s a video to show you what’s happening: https://vimeo.com/170630386/76d0437292

What am I doing wrong?

-Tristan

It’s not shrinking for no reason, it’s shrinking because it thinks that’s what the data is doing. Try turning everything but translation off in problem spots where it wants to shrink, and that should help you get past those parts. You might need to use adjust track to fit it back into place and animate a mesh warp (in nuke or mocha Pro) to get it to match contours.