Re: Confused about MATTES. by John Pale on Apr 26, 2007 at 1:31:29 pm
You can use the matte to make the grass grow over the background video of your choice.
You would do this by placing this matte between on a video track between the grass video (put on top layer) and your background (bottom layer) and then selecting "travel matte-luma" as the compositing mode of the top layer clip.
For more on this and other compositing modes see page III-366 in the FCP Help guide.
Re: Confused about MATTES. by Enge on Apr 26, 2007 at 1:38:18 pm
O.K.
Layer 1 : Background ( Sky, 720 x 576 )
Layer 2 : Grass Fill ( 720 x 576 )
Layer 3 : Grass Matte ( 720 x 576 )
You can see that all these images fill a normal sized SD PAL frame, if you were to layer each of them you would only see the top layer, in this case the matte. What this matte does, when the travel matte luma composite mode is used, is to let you see the background,(sky), with only the white part of the grass showing, it 'cuts the hole' really. That hole is then filled with the Grass fill.
A matte and fill need to be the same length, size and speed, and each needs to be started at the correct frame for them to work properly, if not you get a lag and unsightly black edging, which is just plain wrong.
I hope this helps...