View Full Version : alpha problem in Mental Ray for Maya

11 November 2012, 03:27 PM
I am encountering a problem when trying to render a mib_glossy_reflection shader in maya, no matter what I do the object it's assigned to get's cut-out in the alpha as black.

I tried being smart and just assigning the output of this shader into the incandescence of a lambert and surface shader but that just caused a crash.

The attachment has an image to clarify.

I already tweaked everything around it, so I just need to find a way to fill the alpha of these objects with white. Anybody know how to do this ?

11 November 2012, 03:43 PM
Did you try the "Pass custom alpha" checkbox in the renderglobals?

11 November 2012, 06:08 PM
mib_glossy_reflection is also very much legacy. The mia_material_x_passes is the more modern alternative.

11 November 2012, 10:36 AM
Thanks Nookie,

I am having a hard time locating the pass custom alpha checkbox in the MR renderglobals.

I am using maya 2010

11 November 2012, 03:03 PM
It should be under "custom entities" but I am not sure about how and where it was on 2010. See if this image can help you :)

11 November 2012, 07:43 PM
Hi Nooki,

Thanks for the quick response. I located the button and did a 2 test renders, one with the "pass surface color alpha channel" checked, and one unchecked.

Makes no difference.

11 November 2012, 09:16 PM
Use the mia_mat_x_passes instead.

11 November 2012, 09:55 AM
Yeah in the end I decided to indeed switch over to the mia materials, I was able to get pretty close to the original look, so it all worked out. Thanks for all the advice guys.



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11 November 2012, 09:55 AM
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