After effects white screen footage issue

[Guest]

Hey,

For a personal project, I'm using some VFX footage of smokes unfortunately being on a white background. The thing is, KeyLight doesn't work with that kind of background and despite being able to have some sort of decent result with blending modes, I wish I could find a way to work with that white background as if it was a greenscreen.

Using keylight or any other functionnality provided by AE, can I work my way around that issue ?

Thanks for your help.

[Mylenium · Accepted solution]

can I work my way around that issue ?

Sure you can. White screens scream "(inverted) luma matte" all over the place and of course there is any number of ways to build sort of a manual keyer using channel effects and adjustments. Either way, without seeing your footage nobody can advise specifically.

Mylenium

[Guest]

My footage is one of the smoke plumes available on that link : https://www.actionvfx.com/collections/free-vfx/category

You can see the preview, they're all basically similar so I would like to apply any method to the lot of them since they have the same background.

Thanks.

EDIT : Alright, so I actually with a bit of experiment after my unsuccessful research, manage to get rid of the white background ! I will share it here if anyone is having the same issue.

Basically, all you have to do is invert the colors of your footage, by using "invert" in the effects>channels, then you'll use a "shift channel" from the same menu and modify the first alpha to "luminance", that'll get rid of the background who's now black. Then just apply an other invert and you have it ! You can also remove color matting to clean it up.

Problem solved then !

[Mylenium]

Basically, all you have to do is invert the colors of your footage, by using "invert" in the effects>channels, then you'll use a "shift channel" from the same menu and modify the first alpha to "luminance", that'll get rid of the background who's now black. Then just apply an other invert and you have it ! You can also remove color matting to clean it up.

Which is what I was hinting at when mentioning channel effects...

Mylenium