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Matte-shadow object refractions? How in god's name do I do that?!
show user profile  daniel frisbee
In these images, there is a 3d composited wire structure set into a filmed set, with a big diamond. The wire character travels behind the diamond... but the alpha channel doesn't carry the refractions of the diamond...
I've tried as many variables as I can think of but had no luck...
If anyone knows you would be seriously saving my bacon!
Thanks,
daniel

This first image is inside max
This one is a render from within max with the video reference background
This is after effects trying to use the alpha channel
This one is with a refracting material rather than a matte-shadow
(I tried many times setting refraction to the matteshadow material but alas no joy...
This is the alpha channel clearly not carrying any refractions...

see what I mean? I clearly don't know what I'm doing, but if there is a setting to include reflections and refractions in an alpha channel that is what I think I need...

Hmmm...?
read 339 times
6/20/2010 3:41:10 PM (last edit: 6/20/2010 3:48:08 PM)
show user profile  graphix72
Well, I'm no expert, but think about it: An alpha channel will not carry reflections/refractions because an alpha channel is transparency information. So if the surface is 100% reflective, the alpha channel for that surface will be white. If it's 50% reflective, but otherwise transparent, the alpha channel will be medium gray. But the reflections/refractions will not be a part of the alpha channel.
I think you're trying to capture reflections/refractions in alpha, but I don't think that's possible. You will have to do it a different way, I hope some of the experts here will give you a solution. But as far as I'm concerned, alpha will not do what you want.


read 317 times
6/20/2010 4:15:31 PM (last edit: 6/20/2010 4:15:31 PM)
show user profile  daniel frisbee
you're right...
Someone got back to me, it needs to be a separate render pass for refractions... trying it now... very confusing... It's in the render elements bit..
read 309 times
6/20/2010 5:08:04 PM (last edit: 6/20/2010 5:08:04 PM)
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