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View Full Version : Subsurface scatter shader and straight alphas

vg1
12-31-2008, 01:24 AM
Is it possible to render straight alphas from an object with a SSS shader applied onto it. When I render out premultiplied images, the images and alpha render out fine. When I render out straight, for some reason, my SSS image is engulfed with a nasty white overlay. I'm not referring to the straight alpha edges that get rendered out that need to me composited to see them work, I actually get a complete white mess over my entire SSS render. Any ideas as to why rendering straight alphas may be conflicting with the SSS shader?
vg1
12-31-2008, 03:24 AM
Ok, I think I'm on to something. In the mentalrayTexture node of the misss_fast_simple shader, there is a File Size Depth attribute that defaults at 32 bits. If I render out as premultiplied...the shader renders out fine. When I render out as straight, I get a blown out "white" image. When I change the File Size Depth from 32 bits to "16 bits", it seems to render out the straight alpha without the "blown out white overlay" but, the color is a bit off in comparing it to the premultiplied beauty image, perhaps because I switched it from 32 bit down to 16 bit depth. Can anyone explain why I am getting blown out "white" images when I render out straight alphas with the File Size Depth attribute in the mentalrayTexture node of the misss_fast_simple shader set to 32 bits?