Setting moving masks on imported composition from Photoshop

[tareyza]

Hey guys, I have a question about masks.

So I imported an fairly simple image from Photoshop containing transparency as a composition in AE. I wanted to apply a moving mask to it. However, the imported composition is significantly smaller in pixels than the main composition I am working on. When I apply the mask, I discovered that it was applying to the composition as if it was the same size as my main composition, and the mask didn't apply to where the imported composition was physically. (The mask is a rectangular layer that is animated.) Is there a way for me to expand the imported composition to the dimensions of the main composition by keeping original size, position, and orientation by increasing the transparent area to the size of my main composition, or is there another way to solve this problem? Thanks!

[Szalam]

When you say "moving mask", could you describe what you're doing?

Putting a mask on a layer should have no problems, but the Set Matte effect would cause issues if the scales were different. Creating a solid layer, masking it, and using it as a track matte should also work.

Screenshots of your full interface would really help us to see your problem more clearly.

[tareyza]

By moving mask, I am using set matte on the composition to make the alpha channel matte a rectangle that goes down the screen. Both the blue rectangle, the mask, and the composition, have scale 100%.

Imported composition:

Mid-anmation:

End of animation:

The intent was to have the entire imported composition be displayed in front of the blue rectangle, which also serves as the mask.

[Szalam · Accepted solution]

The Set Matte effect is the issue. It currently only works if both layers are the same size. (Join me in filing feature requests to improve its functionality!)

Duplicate the layer (using the copy with property links option if you want to make sure any changes you do to one are reflected in the other) and use one as a Track Matte instead of using the Set Matte effect.

[Roei Tzoref]

A few other ideas. I am with my phone so can't test all of it or show how it's done but:

1. What if you set the blue rectangle as vector solid by toggling it's continuously rasterize switch in the switches panel? Does set matte behave then?

2. same as option 1 but with a rectangle shape layer (which you can apply a feathered mask if you want)

3. If these are the only 2 layers in the composition then lose the set matte and you can use preserve underline transparency switch which is located in the modes panel for the logo. This is Ae's Photoshop's clipping mask.

[tareyza]

Thanks Szalam! Your solution worked. I will definitely let Adobe know in a feature request.

[Szalam]

Glad it worked!