Procedural Textures and Gamma Correction

#1

So I was adding some gamma correction to my scene and when I finished everything I noticed that a wood texture that I had created with the procedural textures is a lot darker than it should be. The texture is almost black.

All of my other materials look fine except for the wood. I would prefer not to have to retexture the table, but I’m not sure if the problem can be fixed.

This is what my material looks like right now.

I didn’t bother putting any gamma correction on my bump maps. I also didn’t put gamma correction on the solid fractal which is connected to diffuse on my material. Whenever I try and connect the gamma correction with the diffuse on my material it just sends me to the connection editor. Also in the connection editor diffuse doesn’t show up anywhere.

#2

Why are you using 2 gamma nodes in the same chain? Correct only once per channel, before plugging it in the material slot. Also correct only color slots, not value ones. Btw, what type of material are you using?

#3

I was placing 2 gamma nodes in the chain because one file was connected to color and the other to vein color. It does make sense that you would only need one though. I wasn’t really sure though because I haven’t really used procedural textures much.

I am also using blinn, I may change it to mia material x though.

#4

Hi there

Someone will obviously correct me if I’m wrong but I’ve always thought that procedurals do not need any gamma correction because there’s no conversion whatsoever done to them as they’re calculated ( why would the coder of a basic noise embed ie. sRGB conversion into the code ?? ) so just leave procedurals be, my friend :slight_smile:

And for the file textures, you can convert them with imgcvt ( mr - utility ) to linear space so you wont need any gamma nodes in your shader networks.

/Risto

#5

I think it depends how you setup the procedural node. If you do it by manipulating the values and check the result in the color managed renderview, you will need no conversion.

But if you do it in the hypershade by checking the swatch images, you set the values in way it looks good in the default sRGB color space of your display. So they would appear wrong in the rendering and needs a gamma correction.

#6

call me old-fashioned but why would anyone care anything else than a render ?

:wink:

/risto

#7

I thought that it wouldn’t need the gamma correction, but when I rendered it looked really washed out. It might just have to do with my lighting though.

#8

you shouldn’t have two gamma nodes in the same chain

either use one at the very end of the chain, or use one for each and every color input.

Do not gamma correct the color and then gamma correct the entire result. Either correct the result or all the input attributes. Technically you should be correcting all the inputs to get accurate mixing, but this is a royal pain. Since this is procedural anyway there’s already some artistic license anyway so most people just gamma correct the result at the end of a chain.