AE alpha channel issues
by Matt Ziegler
on
Sep 23, 2008 at 7:00:23 pm
Hey all -
I have an AE comp where I have motion tracked a jib shot of a news desk. There is a green screen behind the anchors that I have keyed out with keylight 1.2 and cleaned up with Key Correct Pro. Everything seems to be working correctly and I can see through to the transparency grid but when I place a layer behind the set to fill in the keyed out area it doesn't show up. I've tried movie clips and generic solids and nothing shows through but the transparency grid. Anyone have any idea what I'm doing wrong? Thanks.
Re: AE alpha channel issues by Dave LaRonde on Sep 23, 2008 at 7:16:03 pm
If you have your background layer placed below your chroma key layer in the timeline, it sounds like you might be looking at your video in the layer window rather than the comp window.
Don't expect to move that background to reflect the motion of the jib very easily. You might want to look into a plugin called Syntheyes, which can generate camera movement information for a 3D application.
After you animate the background in the 3D app, you can use it as the background for your chroma key in AE, and the two motions should match up nicely.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: AE alpha channel issues by matt ziegler on Sep 23, 2008 at 10:12:03 pm
Thanks for the quick responses guys. I am using the comp window and I checked all of my switches. Nothing solo'd no transfer modes, no track mattes or anything. It's a mystery. I did manage to get it to work by pre-comping all of the foreground stuff and then placing the background below in the new comp. Thanks again.
