View Full Version : diffuse render pass black for some surfaces

08 August 2010, 06:31 AM

i am trying to render passes of my image and had to notice, that some objects render out completely black in the diffuse pass.
the beauty rendering and other passes seem to work fine.
the bug it seems to be connected to the shader. if i simplify the shader or even use another one for the object it renders out fine.
someone knows that and the reason for it and even better: a workaround?



08 August 2010, 07:13 AM
What shaders and pass system do you use?

I found strange behavior of mia_material_x_passes:
diffuse_raw pass whould be black if you set material color to black (or if you have texture with black areas connected to color- this areas would be black in diffuse_raw pass ). My solution for this very simple- increase a litle bit black value.

08 August 2010, 07:39 AM
MR pass system does not accept mixing Maya shaders with the MIA shaders. You will get these issues if you do.

Solution is to work with one or the other exclusively.

You can still use maya nodes inside the network, just not the last one that is connected to the shading group.

08 August 2010, 06:36 AM
hey and thanks for the infos.
unfortunately non of them applied in my case.

the shading network consisted of a blinn shader with maya only shading nodes (files, textures, ramps, color remaps, blend colors). it seemed the complexity of it had some to do with the problem because when i disconnected some of the connections to the blinn, it worked sometime. but i was not able to find any "bad" node, that really caused the problem.
at first i tried to clamp all values - nothing.
then i tried to be sure i had no black values as proposed - nothing.
i replaced the blinn with a MIA passes shader. worked as unreliable as the original one, but a *bit* better.
desperately in the end i replaced all the blend color nodes (4) with ramp textures. after that one the passes all did work for that object.

so: still no idea what caused the problem, because blendColor nodes usually work with passes :/

cheers & thanks


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08 August 2010, 06:36 AM
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