Video Mask

hello vvvvunny vvvvolks,

how can i mask my video or is it possible to use an embeded alpha channel? i have seen there is already a luma and chromakey.fx but is that really the only way to solve that?

i work with several silhouettes of acting people on a clean white background (recorded on green-screen and already keyed in after-effects). i want these to interact with each other but i have always that damn white background rectangle around.

maybe there is a simple trick or a node i don’t know yet?!

thanks in advance
daniel

May be a tricky combination of blend mode.nodes is what you need. Like Photoshop you can use a sort of multiply, which copies only the dark part of overlapping images.
Actually its a simple comination ;D
check patch…

blendmode.v4p (12.5 kB)

The lumakey can inverse luma and so keyout the white, is that not working for you? Effectivly what they do it say white (or black) within a threshold is the alpha channel…

thanks for the replies.

the lumakey is working but it makes a very pixelated outline.

i hoped there is a possibility to use the video alpha channel cause it has very smooth edges.

You maybe can try using two videos…

One with the masking channel as a black and white video and one with the original video, and mixit usng the blend fx, using color as alpha (or color as inverse alpha).

I tried this effect with non animated masks images with very good results, maybe it can work with video inputs either.

I just noticed that the blend fx that i am using came with tonfilm´s svvvvitcher

Svvvvitcher

@dandesign:
for the reason that there are no example files from you i only can guess:

if you make use of DX9Texture (EX9.Texture) (or related nodes) see the pin Format which is hidden by default. maybe another setting like e.g. A8R8G8B8 already helps enabling an alphachannel.

as a second one of my very first shader-attempts perhaps is helpful here:
TexCtrlFade.fx
scroll far down at kalle.Shader to find it.

@drakko and @kalle

i will check your suggestions out on monday when i have access
to the video footage again and tell you about the results.

I think the way to do it might be to change the col.a=alpha line in the template shader to col.a=col.r;
This will copy the B/w values straight into the alpha channel, see if that gives you a better outline…

I’m not infront of a pc at the moment so can’t be exact, but hope that helps…