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HELP! Nested Comps and Alpha Problem

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Michael Alperowitz
HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 10:29:30 am

I'm having a problem when I add a nested comp as a layer into my active comp. The problem is I lose the alpha channel. I've played with the "Collapse Transformation" switch on both the nested comp layer as well as the layers in the nested comp (hope that makes sense). I forgot what combination worked but it did but only until I added an effect to the nested comp layer. Then the layer became a solid alpha again.

If this makes sense to anyone out there and they have an answer I would greatly appreciate it. My head is about to explode.

I'm using AE CS4 on a mac snow leopard.


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Dave LaRonde
Re: HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 3:31:15 pm

If you have areas of transparency in a nested comp, AE will see those areas of transparency, plain 'n simple. Your situation simply is no normal, so you've got other issues going on.

Perhaps you ought to tell us what you're doing, what's in that nested comp, the type of footage you have in that nested comp... don't spare the details. If you do, it becomes tougher to make an accurate diagnosis.


Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Michael Alperowitz
Re: HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 6:00:53 pm

Thanks for the response. Yeah, I never had this issue with any previous version of AE.

- I created a comp with a half dozen thin horizontal lines that stretch from end to end. Over each line I placed a small glow effect that slowly travels across the lines. The lines were created by resizing solid layers. The glow is Knoll Light Factory effect.

- I took that comp and placed it in my main comp. That's when I lose transparency as I explained before. The main comp consists of photoshop files and one FCP reference file (720x480 29.97 DV/DVCPRO-NTSC)

- In main comp there is a camera layer and 3D layers. However I am not using the nested layer as a 3D element. On a side note I tried turning off camera layer but problem still exits.

- The main comp uses the NTSC DV preset and the nested comp uses NTSC DV Widescreen.

- One more thing. A work around I tried was rendering the lines as a movie (Lossless + Alpha) and importing but for some reason it seems like AE did not render out an alpha channel. I placed it in both my active comp and a new comp of its own but no alpha.

I'm thinking there must be an issue with the program. Not sure what other info I can give you. Hope this helps.




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Erik Waluska
Re: HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 8:04:15 pm

Do any of the layers in any of the comps have Layer Styles on them? If so, try deleting them - every single one of them- not just turning them off but completely deleting them. By that I mean select the heading "Layer Styles" and delete that so that all of the styles are deleted and Layer Styles is deactivated for that layer.

The layer styles are very buggy in CS3, especially when they are in a 3D comp. They can cause all sorts of weird problems that don't seem to make any sense. Not sure if this is still the case in CS4 but it would be worth a try.

-E


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Eddie Yepez
Re: HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 8:46:22 pm

Hi, this may be silly but when you toggle the transparency button do you actually see the grid? If you are applying the Knoll Light Factory effect you might not have an alpha channel at all since you usually compose it with one of the blend modes.
If that's the case you can make a matte with a copy of the layer, then make it b/w and use it as a luma track matte.
Hope it makes sense.

Eddie


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Michael Alperowitz
Re: HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 9:00:53 pm

You sir are a GENIUS! That was the problem. Cannot thank you enough.


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Michael Alperowitz
Re: HELP! Nested Comps and Alpha Problem
on Nov 5, 2009 at 8:50:05 pm

Not clear on what you mean by Layer Styles. The layers in the nested comp have effects on them. If that's what you mean, obviously it doesn't help me to turn them off/eliminate them since they are part of the design.


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Dave LaRonde
Re: HELP! Nested Comps and Alpha Problem
on Nov 6, 2009 at 4:22:31 pm

Layer Styles was a new feature in AE8. If you haven't used it yet, you probably wouldn't know about it.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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