[Kar Bon]

Thanks for your answer.

Actually the blade is already well tracked when it moves (with AE).

I was hoping that some tool would allow to transfer the position of the moving mask (blade) to the layer (towel), but I’ll keep the layer movement manual then !

[Kar Bon]

Thanks for your answer Cassius !

I actually found out why there’s a line around the blade. I kept the addition mask but I deleted the subtraction mask (kept the layer though).

I don’t know why I used subtraction mask actually, now it works !

[Kar Bon]

“If you’re blade is footage, you could track it with the tracker panel in AE and use that to apply position, rotation, and even scale to your towel (or a null that the towel is parented to would probably be better).”

How would I do that please ?

PS: I couldn’t edit the post I made just before to add this question, and the quote button doesn’t work.

[Kar Bon]

Thank you Chris and Michael for your answers.

Sorry my message wasn’t that clear (I use AE in French and I couldn’t find back the translation table that I once found for AE terms).

Here’s a picture describing more or less what I want to do :

When the blade moves, the green path automatically delimitates its edges (the render software is Keyshot btw).

The towel is actually made of 2 parts, one of the part is behind the blade (hence the mask on the blade), the other one is in front of it.

What I would like to do is that both towel parts follow exactly the same movement as the blade by using the automatically defined mask path for the blade (not by manually defining positions for the towel on the timeline). Is it possible ?

Which part of the link you sent me would be most useful Michael ?

(Sorry if this second message looks like the first one, but I want my request to be clear enough).