What (exact, down to the last decimal point) version of AE are you running?
Could somebody please confirm this for me? Load up some footage, liquify it then add a freeze area mask and see if it cancels out the effect? Just so I know I'm not doing something stupid.
The mask must be set as a freeze area before you do the liquifying. I just tried it to be sure.
I did some liquifying. Then I set a mask. The previous liquifying still happens, but any subsequent liquifying doesn't.
Hmmm. Not working for me. I have a circle and a rectangle in a precomp. The rectangle is animated to move towards the circle then back again. I mask out the rectangle and animate the mask to follow it, then set the mask as the freeze area. Then I apply liquify to the layer and distort the edge of the circle closest to the rectangle. Now, what I'd expect to see it the rectangle move towards the circle and keep its shape because its masked off but what actually happens is that the rectangle also distorts as it approaches the circle. So the liquify effect is working on the masked area too. Seems like the freeze area is pointless if it doesn't respect whatever is under the mask. Note that the animation is happening in a precomped layer, so its just like normal footage with moving content.
Start a new project.
Make a composition.
Make a solid (comp size).
Apply an effect to generate something that you can clearly see liquefying in (grid, fractal noise set all blocky, etc.).
Precompose that (moving all attributes).
Apply a mask, set to none.
Apply the liquefy effect.
Set the mask to be the freeze mask.
Brush the liquefy brush over it. The mask should prevent any liquefy effects from happening.
That's what I did and it worked just fine. I did not animate the mask and I suspect that may be the issue. If what I just went through works for you, but doesn't work with an animated mask, then it may be that the underlying structure of the plugin can't deal with animated masks.
Yes, that also works fine if nothing is moving. It has always done that but I thought that the mask could be animated to 'cancel out' the effect. Perhaps not.
Yep, good idea.
I'll mark thread as answered
Awesome. You might be able to achieve the effect you're after by using a Displacement Map effect with an animated precomp driving the effect. (Depending on what you're doing.)