Currently Being ModeratedDec 19, 2012 9:01 AM (in response to ComedyGuy)
It sounds like your movie doesn't have an alpha channel. You have a few options, first and easiest would be the Luma Key filter. At it's default, it should remove the black, but may need some adjustment. If the trapezoid has any black in it, you may have to do some addtional masking to protect areas that get keyed out because of their lumanance values.
Currently Being ModeratedDec 19, 2012 12:08 PM (in response to GFXZen)
Yikes - right, sorry about that. I did use Luma Key, but it didn't work. I also tried the Screen mode in Blending options, and that didn't work either. Any other ideas? Thanks in advance - appreciated.
Currently Being ModeratedDec 19, 2012 12:35 PM (in response to ComedyGuy)
Are you saing the luma keyer did not remove the black (after adjusting the settings), or it did not give you the complete result that you wanted (removes some of the trapazoid)? Can you be more specific as to what you are not getting that you expect? Can you post a scree shot of the problem?
-Screen over white will not mask, it's like adding white to the forground.
-Is the problem when you export the background is still black? You may need to change the background to Solid or Enviroment in the project settings before export.
-you can also add a white shape or color generator behind the layer you are keying/masking to get a white background.
-If all else fails you could animate a mask shape.
Currently Being ModeratedDec 19, 2012 12:50 PM (in response to GFXZen)
Success! (Sort of!) I followed your advice and changed the background to white and it keyed it perfectly. Only one problem: The animation no longer works. It's supposed to spin, and it doesn't move. I tried a RAM preview thinking it might just be stutter, but nope - it won't move. Any ideas? Thanks again - you rock.
Currently Being ModeratedDec 19, 2012 1:16 PM (in response to ComedyGuy)
The background does not render as part of the composition.
If you go into the Edit/Project properties you will see a notation below the bacground colour selection that tels you that.
Alternatively you can add a colour layer below the others and set it as a 2D layer and this will render out n your final composition
Currently Being ModeratedDec 19, 2012 1:35 PM (in response to Alan Apple Mac)
Thanks, Alan. I added a white layer and it rendered correctly. the only problem now is that the animation won't work. The image won't spin in 3D space like it did with a black background. I'm making progress, so thanks for your help. I'm hoping to avoid animating a mask, but I will if I have to. Cheers.