VRay Color Gamma

[YoyoBoy]

I don't understand what the point in the VRay Color's Gamma Correction roll-out is if it has no affect on how the color renders. Is it just me? Is it a bug?

[rivoli]

usually one would tick don't affect colours when working linearly, and with linear outputs such as exr. this way vray will know that you are rendering with a gamma correction, and will perform the correct sampling in dark areas which would otherwise left undersampled. it will also not affect the actual gamma of the image, so that you won't get double corrected outputs. it's not a bug, rather a workflow option. if I understood your question correctly, that is.

[YoyoBoy]

I'm sorry, I'm talking about the VRayColor map. I should have been more careful. When you change the gamma value of the VRayColor map, the swatch changes, but the rendered color does not.

[rivoli]

aaa ok, I see now. no problem, a simple case of me being dense. anyway, the colour map works as expected here. the gamma correction actually correct both swatches and rendered colours..

[YoyoBoy]

Hmm... I'm messing with every setting there is and I can't get it to change anything but the swatch.

[leehumphries]

i think i read somewhere that the gamma setting is ignored in Vray Colour Map..

[YoyoBoy]

Oh, perhaps I should have mentioned that I am still on VRay 1.5.

[berglte]

I use this for example, when I have to use predefined colors for something and I´m using linear workflow.
Try creating a RGB 0,100,100 color in photoshop and then try rendering something with a value 0,100,100 in the materials diffuse swatch. When you open that render in photoshop, you see that the color is actually 0,165,165 as the image at least should have a gamma of 2,2 applied to it when you save it. (if you try see what the color is with max vfb, max will tell you it is 0,100,100 because the info isn´t gamma corrected)
Now try rendering again with the vray color texture, first specify the gamma to be 2,2 and then pick the color 0,100,100 with color selector. When you open this image in PS, the color is actually 0,100,100 after saving.

So, basically it´s the same thing as with using diffuse bitmaps with specifying the gamma to be 2.2.

[YoyoBoy]

Several hours after I posted this, I figured out a simple solution to this and the color-swatch problem in general, and posted an explanation here: http://www.chaosgroup.com/forums/vbu...l-maps-for-LWF