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View Full Version : Noise reduction causes hair to be transparent



hdace
01-23-2009, 04:45 PM
About a month or two ago, on the OB forum, I started a thread called, "Noise reduction causes weird aliasing". No one ever gave me a decent work-around or explanation and no one could reproduce it.

Now I've got this crazy hair situation with the same scene (nearly finished). If I turn off NR the hair is properly opaque but (using area lights that I don't want to change!) the face is all speckled. With NR on you can see the edge of the skull beneath the hair as if he's backlit (which he isn't).

When is someone else going to have the same problem so I can fog it? Do we still fog when we're out of OB?

hdace
01-23-2009, 04:47 PM
almost forgot the png's!

hdace
01-23-2009, 04:49 PM
changing hair color doesn't help

jayroth
01-23-2009, 05:28 PM
Don't use noise reduction if it causes artifacts for you. It is a very old portion of the code, and fights with the newer stuff. And frankly, with the new AA stuff, as well as the caches, you do not really need it anyway...

hdace
01-23-2009, 10:12 PM
Thanks Jay.

Okay, well it took 28 minutes to render this tiny patch of an otherwise HD-size image. This is with no NR, AA @ 16 & AS @ 0.0314. Oddly enough I think the splotchy shadow on Gabriel's face is worse with high AA & AS than with low (see picture 2 above). BUT, the hair looks much better and of course there is now no skull glow.

I always knew this scene would eventually require higher AA & AS anyway so I guess that's not too much of a s*** sandwich, but I really liked the NR's effect on his face. So I'm gonna have to get used to not using NR anymore.

Thanks again, Hal