Problem with surface

Hi,

I’m working on a proof of concept for a scene where I pull a white paper out of a white envelope.

The idea is to track the white paper and place something on it hence the reason why I put x markers on the sheet.

I’ve tried to track it via Mocha AE, but my surface keeps getting distorted at the moment I pull it out off the envelope.

I think it’s probably because of the change in length of the tracked plane?

Short video to show what I mean

Since I’m pretty new to Mocha, I’m all out of ideas of how to solve it. Any suggestions or tips would be greatly appreciated!

Track from where the object is largest in frame, least blurry, and most parallel to the camera.

In this case that’s from the end of near the end of your shot to the beginning. You can start the track anywhere on the timeline.

Also, you want a holdout shape (either hand rotoscoped or tracked, tracked is easier) around the envelope and you want to drag that above your paper layer before you start tracking.

That will help a lot.

Hi, @maryp Thanks for answering. I started my tracking from a clear frame at the end and then worked my way backwards to the beginning.

The problem is once I’m at the part where it disappears in the envelop, my surface changes perspective.

I think it’s because my tracked plane is getting smaller and smaller towards the “beginning” of my shot?

Are you using a holdout shape?

You mean a seperate track for the enveloppe?

Yes, in the layer above your paper.