Forums Technical Discussion pbr rendering fur artifact

pbr rendering fur artifact

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luoqiulin
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attached pic is renderd with PBR
i don't know why it happen like this, even if i make Min Ray Sample to 4
Max Ray Sample to 12 and Noise Level to 0.01, the black pixel appears some frames also, maybe if the Ray Sample much bigger it will be nice, but the render time is much longer.
any solutions?

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pbr_fur.jpg (163.6 KB)

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sl0throp
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Looks like a NAN to me (Not A Number)…maybe try playing with the ray bias maybe.
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Alejandro Echeverry
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Those “NAN” artifacts shows also when I apply displacement through pyro shader and use any one of the mantra raytracing engines; I had play with the ray bias without luck.
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zdimaria
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http://www.nukepedia.com/expressions/dealing-with-nan-pixels/ [nukepedia.com]
.
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zdimaria
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http://www.nukepedia.com/expressions/dealing-with-nan-pixels/ [nukepedia.com]

and that fur is looking nice!
.
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luoqiulin
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thank you
ray bias not works for me too, i even decide to fix it with houdini comp.
but the nuke's solution is simple
i wish it can be fixed in houdini render
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halfdan
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luoqiulin
thank you
ray bias not works for me too, i even decide to fix it with houdini comp.
but the nuke's solution is simple
i wish it can be fixed in houdini render

This is bad.

Can you post the .hip file so we can take a look and see what's causing this?
Halfdan Ingvarsson
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Side Effects Software Inc
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luoqiulin
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halfdan
Can you post the .hip file so we can take a look and see what's causing this?
i'm sorry that i can't take the origion file out. here is a simple file with black spot too. the same shader light setup,just no reflecter.

Attachments:
pbr_fur.hip (2.0 MB)

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halfdan
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luoqiulin
i'm sorry that i can't take the origion file out. here is a simple file with black spot too. the same shader light setup,just no reflecter.

That's perfect. Thanks!
Halfdan Ingvarsson
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Side Effects Software Inc
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andrewc
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The nans were caused by the old wirediffuse() bsdf that was being used in the shader in this scene. It should be fixed in the next build of 12.0.

Andrew
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luoqiulin
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good news
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