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fadgadget
04-11-2009, 11:44 PM
Hi,

I would very much like you expert opinion on the following :

I'm trying to create a material with a tiff-file, with transparency information, loaded in the color channel to cast a shadow.
(I'm using a stop motion animation of a character shot in front of a greenscreen, the background is keyed out)
Unfortunately in all my experiments I see not only a shadow of the character from the tiff-file but also of the plane to which I've attached the material.
Who can tell me how I could get rid of everything else besides the shadow from the tiff-file loaded in the color channel of my material?

jeremybirn
04-12-2009, 02:48 PM
What software are you using?

Depth maps (shadow maps) don't support transparency generally, but raytraced shadows do. If you cast a shadow of a transparency-mapped plane, you should expect a light with raytraced shadows to shine through the transparent areas and only be blocked by the parts that aren't as transparent.

-jeremy

mister3d
04-12-2009, 04:35 PM
What software are you using?

Depth maps (shadow maps) don't support transparency generally.

-jeremy

Just curious Jeremy, are there types of shadow maps that do support transparency?

mister3d
04-12-2009, 05:00 PM
Thank you, that's interesting (posts travelling in time again :D ).

jeremybirn
04-12-2009, 05:00 PM
Just curious Jeremy, are there types of shadow maps that do support transparency?

Yes, Deep shadow maps in Renderman, and Detail Shadow maps in MR, support transparency, colored transparency, and motion blur. But these are exceptions, regular shadow maps as he's likely to be using don't support transparency.

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