Masking, with camera move

[David5D]

Hi all, I'm undertaking a new project. The basic idea is to mask out parts scenes, for example the sky, and replace it with something else.

In the attached video clip sample, my process is:

Apply an Alpha Matt to original footage, manually mask the Alpha Matt, to remove the sky. Then, frame by frame, animate / track the mask, so it stays aligned with the alpha matt / original footage, during the actual camera move.

I'm new enough to After Effects, so any tips on how to improve this technique would be great. The most important part of the process, I presume is obviously, the accuracy of the mask, as the camera moves.

My approach feels a little stone age though?

Example below:

http://iplayerhd.com...c71132c49/share

Cheers,

David

[Dave_LaRonde]

I don't get what I'm looking at in that example.

I see two pieces of video, both of which appear to contain water -- no sky. 

Where's the sky supposed to go?

[David5D]

Ha. The sky has been replaced by another clip. I think that's fairly obvious, with the horizon.

What might cause some confusion, is the fact that the original clip, which the sky has been taken out of, is actually blended with a third scene, a little bit.

Not a good sign for me, if someone doesn't even know what they're seeing.

[Mylenium]

And exactly what is the problem? There's tons of sky replacment tutorials out there, but it all begins with shooting your footage suitably. Otherwise if you were hoping for a magic button to churn out hundreds of these videos a day, then no, it doesn't exist. For ev erything else simply learn how it's done by looking up those tutorials and educating yourself about masking techniques, tracking, using mocha AE, keying, channel-based operations to generate mattes and ultimately arraniging stuff in 3D for a realistic perception of your composite.

Mylenium

[David5D]

There's no ''problem'', my friend. I was hoping for someone to comment on my process, possibly compare it to their's?

I wasn't hoping for magic button, no.

Thanks, I'll look at tutorials.

[Kevin-Monahan]

Hey David,
Did you end up solving this issue? Let us know how you did so.

Thanks,
Kevin

[David5D]

Hey Kevin, thanks for the reply. I haven't progressed my original idea much, but I've moved in a slightly different direction with it. Here are some latest composite tests. I need to shoot some footage, purposefully, with this technique in mind.

For now, I only have the chimneys as surfaces to work on. It certainly looks 3d though, which helps make it convincing. Very early though. If anyone is interested in the process I used, I'm happy to share

password: 'pw'

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