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How will I get this matte to work?
Hello everybody,
here you can see two small pictures:
https://green.cybton.com/prob/screen1.jpg
https://green.cybton.com/prob/screen2.jpgIn the end I’d like to get a composition which only has these figures left.
How will I do that in Aftereffects 6.5 ?
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7 Replies
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if you mean you just want the characers left and it is a still photo that you are using , it would be easiest and cleacnest to just draw a mask around them.
Chris Smith
https://www.sugarfilmproduction.com -
is is not a still
it’s a movie-clip
so selfmade masking is NOT a way to do this ^^ -
Need more info then. You obviously can’t key it. Are you suggesting doing a difference matte?
Do you have access to the game engine? So you can kill the surrounding and replace it with a keyable BG.
Chris Smith
https://www.sugarfilmproduction.com -
well, I do have access so that I could make the figures completely red/green whatever (I got a tool from a friend, I was unable to do this till 5 minutes before)
but there must be a oppoturnity to do this difference matte, the principle is:
values of pixel a – values of pixel b where a=b .. so where the pixels are exactly the same, they shall be substracted, otherwise not
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Assuming the shot is EXACTLY the same, pixel for pixel with the other shot, the only difference being the figures, then you can use the difference key. However , difference keys usually look rough.
If you can replace the figures with 100% of a flat color, then by all means, key that and invert the matte to isolate the figures.
Chris Smith
https://www.sugarfilmproduction.com -
so I should possibly fokus on the second method:
I can get the same clip which includes the map (the surrounding) and the players in it, but the players will be completely red/green. How will I proceed then ? I do know how to key the red things out (or the opposite of it) but I don’t wanna isolate the red players but habe these as an alpha matte for my clip with map+normally skinend players…
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Have one layer be the normal movie with the dudes you want to isolate. Have a second layer that is the exact same shot except make your characters 100% green.
Drop a color key onto the second layer and pick the green of the dudes on screen. Set the keyer till they disappear. Now you have isolated them albeit with the opposite alpha than what you need. Not a big deal.
Put this second layer (the one with the green dudes and the color key) on top of the normal clip layer. Under the track matte setting, on the bottom (normal) layer, select ‘alpha inverted’. Then it should isolate your guys by using the key you did on the layer above it.
You may want to keyframe some garbage roto around the guys though in case the key picked up other garbage that is away from your subject.
For details on track mattes, alpha channels, etc.. check your help files or manual obviously.
Chris Smith
https://www.sugarfilmproduction.com
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