Lighting help ( Mentalray )

ayoub44

hello
(sorry for my bad english )
i'm having a little problem with my lighting setup ,
when i put a simple color to my object and render , and don't get the same color that i pick , i get it lighter . here is a image :



i and the same for textures :



help plz
thanks you ; how i can fix that ?

Noors

If you're not familiar with linear workflow, then go to
rendering>gamma/lut>disable gamma/lut correction.

.morph3us

http://www.neilblevins.com/cg_education/linear_non_linear_visual_difference/linear_non_linear_visual_difference.htm

Noors

This article is a bit wrong. First, for a correct linear workflow, you have to degamma your diffuse textures, else by setting input at 2.2 in the gamma/lut or setting them individually. Else indeed, your diffuse textures get gamma corrected twice to 4.4 hence they're all washed out. And If you use a color from color picker, gamma has to be taken in account too. I'm used to vray where it's easy with a vraycolor node but i don't know for MR.
But keep gamma 1 for bump/normal/displacement maps
The gamma correction is applied at the end of the calculation on the complete picture.
I find a bit weird to apply level curve for his purpose as there is a gamma/exposure tool in photoshop. No need to say you'd better output a 32bits picture to adjust that.
Now i agree that you don't necesseraly aim for a realistic result, and you can always play with different gamma settings, but incorrect workflow is the reason why we had "3d looking" pictures with burnt areas and dark shadows for 2 decades.
LWF is easier to setup (no need to cheat with ambient lights), gives the correct and natural look, and compute faster.