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alpha channels

Posted: Mon Mar 05, 2012 1:43 pm
by pipcleo
Doing a render with a background and need an alpha also.

Any way to render the image with background and an alpha in one pass ?

I notice that rendering just the alpha channel (alpha checked , diffuse unchecked) that the diffuse will also render.
Is this normal ?

Re: alpha channels

Posted: Mon Apr 23, 2012 11:13 pm
by martgreg
Check both fields render and alpha

Re: alpha channels

Posted: Tue Apr 24, 2012 1:50 am
by Bubbaloo
You won't get a clean alpha cut out with a background image + alpha. It renders black to get proper AA edge transparency.

Re: alpha channels

Posted: Tue Apr 24, 2012 2:39 am
by rusteberg
pipcleo wrote:Any way to render the image with background and an alpha in one pass ?
you can render a depth pass and set the min value to 0 and the max value to something bogus like 9999999 and use that as alpha....

edit: combobulated reasoning on Bubbaloo's post here: http://support.nextlimit.com/display/ma ... ha+channel

although it's a bit discombobulated....