View Full Version : Q: Alpha channel

02 February 2005, 08:04 PM
I have an object that I am rendering on a plane w/ FG to get a shadow underneath it. What I want to do is also get an alpha channel of this that only has the object and shadow - I don't want the plane. I can do ambient occlusion and then multiply the layer on top of another and that works great, but I need to export this as a transparent PNG for Flash and am not sure how I could achieve this. Any ideas? Thanks!

02 February 2005, 11:27 PM
Have you tried the background shader (i think that's what it is called), at the bottom of the list where lambert and phong are?

Applying that to the plane will make the plane the same colour as the background and you will only see shadows and reflection.

Also it doesnt render the plane as part of the scene so wont appear in the alpha channel.

02 February 2005, 11:35 PM
Gremlins are evil.

02 February 2005, 11:57 PM

If youre talking about my avatar, I think its just a cat with a silly face, so fear not!

02 February 2005, 12:53 AM
Yes I was referring to that. It just gave me a flash back to the 80's and feeding the cute little furballs after midnight.

That is the ugliest cat I've ever seen in my entire life though.

02 February 2005, 01:02 AM
Thanks for the replies! Tried the background and that didn't work. I was thinking maybe I could mess with the settings on the surface shader but I can't seem to figure anything out with that either. Any more ideas?

02 February 2005, 01:11 AM
As you have noticed the useBacground shader does not respect final gather shadows. This is fixed in Maya 6.5 so your options are to upgrade to 6.5 or....use the solution in this thread for your problem:


02 February 2005, 01:49 AM
Perfect, appreciate the help :).

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02 February 2006, 02:00 AM
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