What colour space do I set my image textures to? Linear or sRGB?

[Johnny_Naro]

Hi everyone,

Long time lurker, first time poster. I'm having a tough time understanding the documentation on linear colour space workflow. I'm using Arnold 5.2.0.0. For my image textures, what should I be setting the colour spaces to? Linear or sRGB? Within Arnold's render settings, I'm using the built-in colour manager & within the IPR, I have the colour space set to sRGB. Within C4D I have linear workflow selected & input colour profile set to sRGB. Is that all correct? I know that the documentation requires bump maps to be linear. But other than that, I can't find any info on diffuse, specular, normal maps, displacement, etc. Any help would be appreciated, thanks!

[peter.horvath6V6K3]

> For my image textures, what should I be setting the colour spaces to?

I'd recommend using auto which will consider 8bit images as sRGB and floating point images as linear. Normally that's the case. There are some situations where you have to manually specify the color space, for instance a normal or displacement map contains the raw data, so you set them to linear, telling Arnold you don't need any color space transform.

> Within C4D I have linear workflow selected & input colour profile set to sRGB. Is that all correct?

Yes, that's fine.

[maxtarpini]

Frankly it's hard to tell right now. Generally you want only the albedo(diffuse) texture to be linearized. All the other textures should be considered already linear as they hold data. Yeah all the other textures..

But then you may ask yourself.. why 'auto' or 'srgb' is set by default ? Yeah that simply ain't making any sense. (It happens because engineers do not care while product designers still don't get what a linear workflow is 🙂

For example. Set a 0.3 value for all your textures in substance painter. You may expect that when you export them as ie. png.. painter is gonna convert them into srgb.. but it's not. So when you have defaults active and your texture is read in any DCC apz.. is gonna be linearized even if it does not need it.

Now considering that almost 99% of texture packs outthere do not uses exr or other linear format .. 99% of all the textures are first transformed into linear and then .. ppz while working on shading.. get the correct visual appearance just because they 'remap' them into something that's gonna visually work.

That's the same reason why ppz will tell you that 'normal' textures need to be linear.. because they're the only one that if not linear you'll see in an instant that they are impacting your shading in the wrong way (but not the others that will alter only the visual appearance without making it necessaty looking 'wrong').

So 🙂 engineers do not care, designers do not get it and artists just try to fix it and make it work.

What's left ? 🙂 Simply that you export a dummy set of textures from your painter apz and check them to see what you really need to do.

Exported pngs from painter..

Rendered with defaults in Arnold. The right is manually set to a fixed 0.3.. the left should be the same.. but you need to set it to raw to work correctly.

You may then ask yourself how to behave when you download a roughness png texture from the internet. You may have no way to tell what was the initial data meant to be (if not ping-ponging between the values you may have in the texture and the appearance you're expecting to have) however looking at the above misconception is generally better (at least theoretically and not because of the format being used but because roughness for example is not an albedo but it's 'data') you set them to linear/raw.