-
“Stencil Alpha” – Not What I Thought
I have a logo (the letters ‘aim’) that I want to turn into a window that the video shows through. Then as the logo scales up, it reveals the entire full screen of video.
I can make it work using Stencil Alpha, as long as the video clip I want to use is inside of AE. However, I’d like to use this logo on top of clips in Final Cut. When I turn off the video clip (inside of AE) and send the logo out to Final Cut, the transparency from Stencil Alpha doesn’t exist.
How do I tell AE to use my logo as transparency, so that I can lay this logo over any video clip in Final Cut and have the video show through the logo?
Thanks for your help!
Nate*
* Author has no real-world experience; he works in the plastic-bubble world called “Public Education”. -
3 Replies
-
Unfortunately I think you’re going to have to do that effect inside AE. Transfer modes are a funny thing, they rely on the pixels of the layers underneath so if you isolate that layer, in your case a “stencil alpha”, it only has half the information to make that work.
Try dropping a fill effect on your logo, make it pure green
(0, 255, 0). Then key it in FCP.Or use the track matte inside AE. (may or may not give you what you need)
-
Try this:
– Pre-compose your background (everything except the logo) in After Effects so you’re left with the logo layer and the background pre-comp layer.
– The logo should be on top of the background layer.
– Set the background layer track matte to “Alpha Inverted”. Now you should have a cutout hole in the background in the shape of the logo and you should see the transparency grid (if not, turn on “show transparency grid).
– Animate the logo scaling up (use keyframe assistant>exponential scale for best results) to fill the screen.
– Render it out as a movie with an alpha channel.You should be able to bring that into FCP and drop it on top of whatever video you want to reveal.
Hope that helps.
-E
-
Hey guys, thanks for the help. I got it to work with this solution:
Made a copy of the logo and placed on top of the precomposed title sequence. I used it as a track mat set to Alpha Inverted.
The great thing about that (as opposed to stencil alpha) is that you can fade in the layer and the layers below are only affected relative to the amount of the layer’s own opacity. Stencil Alpha, on the other hand, acts like a cookie cutter at all times…even if it’s own opacity is set to 0%.
I sent it out to Final Cut and it works just like I wanted it to.
Thank you for the help – saved me a lot of trial and error time!
Nate*
* Author has no real-world experience; he works in the plastic-bubble world called “Public Education”.
Reply to this Discussion! Login or Sign Up