Mapping images over movies in FCP?

[Petey05]

Hi. I'm a FCP novice.

I want to enter the Colbert "McCain Challenge" where a greenscreened version of McCain is placed in "interesting" situations.

Somebody made this youtube video: http://www.youtube.com/watch?v=8G9jA-FGGd8

Where they took his head and mapped it over the body of one of the performers. I want to do the same thing for another music video.

I've already chroma keyed and cropped til I have just his upper body (still need to crop down to the head) but what I don't know how to do is map it to the head of one of the performers the way the other guy did. I don't even know what that technique is called so I can't do any research on my own.

Any info that might point me in the right direction would be greatly appreciated.

Thanks!

[AviationFan]

That's a funny video - I like the idea!

As far as "mapping" goes, do you mean to move the position of the image around so it matches what it's replacing? I think your best bet is to define keyframes for the position (and maybe the scale) of the image. There is a feature called "tracking" in Shake (maybe in Motion too? not sure...) which automates this process, but it requires an easy to identify point that it can track - you may or may not have such a point.

Or did I misunderstand your question?

- Martin

[Petey05]

That's a funny video - I like the idea!

As far as "mapping" goes, do you mean to move the position of the image around so it matches what it's replacing? I think your best bet is to define keyframes for the position (and maybe the scale) of the image. There is a feature called "tracking" in Shake (maybe in Motion too? not sure...) which automates this process, but it requires an easy to identify point that it can track - you may or may not have such a point.

Or did I misunderstand your question?

- Martin

I'm trying it in Motion. It's very hard because the "Thriller" video is dark!

Actually the biggest problem I'm running into in FCP is that I can't figure out how to key just McCain's face. I can use the green screen to get his upper body in the video, but I can't key on his face no matter what I do. Is there some sort of "color based crop feature" besides chroma keying that I'm missing?

[AviationFan]

Actually the biggest problem I'm running into in FCP is that I can't figure out how to key just McCain's face. I can use the green screen to get his upper body in the video, but I can't key on his face no matter what I do.Sounds like a job for rotoscoping. Section 12 of the Motion 3 manual explains how to do this. It's labor intensive, because you have to keyframe the rotoshape pretty much frame by frame - but that's what is used when automated techniques (like chroma keying) don't work.

Here's a video that shows some of the things you can do with rotoscoping:
http://www.youtube.com/watch?v=z32h-b9-8Qw

- Martin