Keeping a mask still!

[Kevin Camp]

you can’t unlink a mask from a layer… you could animate the mask to act counter to the animation of the layer, but that’s usually not the easiest way….

i would copy the mask, and paste it onto a new solid. position the solid directly above the ai layer that is masked. select ‘alpha matte inverted’ from the track matte pulldown for the ai file (this is an option in the modes panel in the timeline). now you can remove the mask from the ai layer, and the ‘mask’ will be separate from the layer’s animation.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Todd Kopriva]

I’d precompose the layer, add the rotation animation to the layer inside the precomposition, but add the mask to the precomposition layer. If you’ve already created the mask, just cut it from the layer inside the precomposition and paste it onto the precomposition layer.

Does that make sense?

For information on precomposing, see the “Nesting, precomposing, and pre-rendering” section of After Effects Help.

CreativeCOW also has many articles related to the subject by clicking on the following link…

https://library.creativecow.net/search.php?q=precompos

————————————————————————————————–
Todd Kopriva, technical editor, Adobe Systems Incorporated
putting the ‘T’ back in ‘RTFM’ : After Effects Help on the Web
————————————————————————————————–
How about taking a survey about After Effects documentation? Please?
————————————————————————————————–

[Roland R. kahlenberg]

Masks are rendered before Transforms and Transforms are rendered after Effects. Your AE render pipeline looks like this Mask>Effects>Transform.

This is why your mask is being rotated along with the layer. If you have Collapse Transformations switched on, the render pipeline changes to Transforms>Mask.Effects.

I’d suggest that you switch on Collapse Transformations. It should work but hopefully the change in the render order doesn’t disaffect anything else that you may have applied or changed to the layer.

Cheers
Roland Kahlenberg
https://www.broadcastGEMs.com – Adobe After Effects project files
https://www.myspace.com/rorkrgbspace

[Kevin Camp]

good tip, thanks roland…

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Ian Collister]

Cheers all!
I went for Moldys first reply. It worked a treat. Thanks again.

c

[Jon Merrifield]

For anyone else looking for this.
You can hold down the Y key (the pan behind tool)to re-position the fill inside your mask. For rotation however, I just use an alpha track matte on a mask only layer…

Jon Merrifield
PELi VFX

[John Lucas]

Hey, Jon! Very nice tip! I was googling around for tips about masks, just got into this post, and your reply was really helpful!

[Andy Hall]

I am having trouble with the fill inside mine – I preposition the fill using ‘Y’ – but it affects it in another part of the mask. OR the mask has to zoom to accommodate an image coming toward the camera, and there isn’t enough composition stage behind the mask to work. See image: