View Full Version : Compositing shadows without an alpha channel in Fusion

06-19-2007, 01:11 AM
Hi there.

I am rendering seperate shadow passes from Maya per Jeremy Birns method as seen here:

How can I use these in Fusion?

What nodes or combo of nodes would I use to extract an alpha channel?

06-19-2007, 09:02 PM
You'll get the shadows alone in the red, green, and blue channels. You can just channel boolean them... for instance to get the red-channel shadow alone and in greyscale, just connect the shadow pass to a channel boolean as the background and set the RGB outputs to be the red-channel background layer. Then do the same with seperate boolean nodes for the green and blue.

06-19-2007, 11:08 PM
hi there

thanks alot !

that worked for the most part.

What operation do I use?

I just have red shadows, not green or blue.
I connected the shadow to the bg input of the booleans node and then I changed the "to red" channel to "Background Red FG"

The shadows are still red though. How do I get them gray scale and pre-div and post-mult them?

06-19-2007, 11:10 PM
oh yea, also in the merge node, what blending option should I use?

over, screen, or multiply?

06-20-2007, 03:37 PM
Hook up the shadow matte to a Color correcter and darken the background to taste.

06-21-2007, 06:16 AM
thanks alot for the tips. got it all to work cept for being able to tint the shadows with a color.

06-22-2007, 10:16 PM
im new to fusion i dont no how to compose pauses so plz guide me how to compose.
if any tutorial sites for pauses compositing means plz send me site details plzzzzzzzzzz

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