Utility Raw from Mari to Maya/Arnold

Hi there, I was hoping someone could help me understand a problem I’m having.
I’m setting up a disp map in Mari with the colorspace set to Utility-Raw, my mid gray base layer is set to 0.214.
I’m exporting this out of mari with the colorspace set to Utility-Raw and as a test I’m reading the map into emission with the colorspace set as Utility-Raw in Maya/Arnold.
In my render I would expect there to be no change in the values but when I color pick my emission render in nuke I get a value of 0.49904. How can I get raw values from Mari to Maya without this value change.



Unfortunately Mari color-picker is display referred and if not mistaking hardcoded to sRGB so entering scene-referred values can become painful.

Rory (from Foundry) explained me how it was designed and you can fin its explanation here:

You can join the Mari Discord server linked at bottom of the page and ask more about this.


Thanks for your reply Liam,

Its strange to me because if I set the channels colorspace to ACEScg to begin with then change it to utility-raw, on export I get I get my linear 0.214 value.

Even if I start with the colorspace Utility-raw, if I color pick the raw values its still 0.214 but on export under Utility-raw its 0.5.

Do you know what transform is being applied here and a which stage this transform is being applied?



Hey, I still didn’t get how exactly the color picker was working but from what I understanded if you need to enter a scene-referred value, you need to enter the corresponding display-referred value with the inverse sRGB EOTF applied.

For example in Nuke I would do :

And enter 0.214 in the color picker which, when I export the texture and color pick it, would give me 0.5.

And by the way, if your working space in the OCIO config is set to ACEScg you don’t need to set the IDT at export to Utility - Raw, you can keep it ACEScg for all the maps.