Where to find opacity mask in FCP X?

Is it possible to composite one image with another using some sort of opacity mask? It's such a basic technique that I'm sure it must be there somewhere but I can't find anything about it in the manual or online.

I know that the Alpha channel is generally used for this sort of thing in other CG programs, but I don't see how to access that in FCP X.

I'm not talking about animating the Opacity through time, but having, say, the central part of the upper image be transparent while the outer part is opaque.


I've searched this forum and the FCPX forum at Creative Cow but I can;t seem to find an answer. Any help would be appreciated

Have a look at the effect I created here:

fcp.co/forum/9-free-fcpx-plugins-and-tem...organic-opacity-mask

It might be what you're lookoing for. Do let me know if there's something that would make it more useful for what you have in mind.

Thanks Simon, this looks perfect, esp. the ability to use full-motion footage for the mattes.

I'll reply with more detail after I figure out how to install it. (Tried copying into ~/Movies/Motion Effects/ but I can't see it in FCPX)

- Bruno

[edit] - got it working now - looks good! Thanks again.

Also play with composite modes.