View Full Version : Mental Ray Car Paint Shaders and Mental Ray Physical Sun/Sky

11 November 2009, 08:10 PM
I have a scene I have setup with a Mental Ray Physical Sun/Sky with default options (except for the direction I have the sun facing).

I have a car in the scene that I threw on a mental ray mi_metallic_paint_x shader on with default values.

As you can see in the image, when I render the scene, the paint color is very orange instead of the red I expected that the shader sphere shows.

I have been playing with the shader trying to make it look red like it should but I'm not having any luck.

Is this common behavior? Where do I start to fix this?

11 November 2009, 08:31 PM
try adding a gamma node to all your color slots inside your material, set the color and then add a gamma value of .4545

11 November 2009, 08:52 PM
Ahh that did the trick. For some reason I thought the .454 gamma trick only applied to textures.

Kinda dumb that you are expected to make this gamma adjustment to pretty much everything in your scene when using Mental Rays physical sun and sky. You would think it would automatically account for it so it doesn't wash everything out.


11 November 2009, 12:22 AM
A simple fix is to set your Framebuffer's gamma to .454. This will be a global fix for your scene, although it's not the "accurate" way to do a linear lighting workflow. This way you don't have to degamma every single little node...

11 November 2009, 06:46 AM
This way you don't have to degamma every single little node...Actually, even if you do this, you still have to degamma the color swatches. But you dont always need extra nodes to do it if you are brave and just make your colors darker. Works for me. :)

-- David

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11 November 2009, 06:46 AM
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