Its only half the solutiom. I need to apply the right view transform now.
If i manage to get it working i update the thread here.
This node looks fine to me.
https://natron.readthedocs.io/en/rb-2.3/plugins/fr.inria.openfx.OCIODisplay.html
But i cant get it to work.
But it did look right in the viewer before. Didn’t it?
What colorspace you plan to output?
The image above is untonemapped.
I like to us the new Viewtransform “ACES 1.0 SDR-video” like in the Arnold Renderview.
Like in the first image in this thread.
Not exactly sure what you are after but from my limited 3D experience with Maya you won’t get it to match properly.
This fortunately isn’t correct, both should absolutely be able to be matched… That’s kind of the point of colour management! If your colours aren’t matching in a colour managed workflow something is wrong with what you’re doing or what the software is doing and should be sorted out. In this case I think the issue is on your end so with some settings tweaks we should be able to make it work! 
I don’t know what you (or anyone else who stumbles upon this) are already familiar with so I’ll just try to explain the whole process, pay attention to parts that concern and don’t concern you accordingly!
Firstly, I’d recommend using the official OCIO config for both programs. Maya 2022 comes with an ACES config but just to iron out problems and making sure our settings are in sync here I’d recommend downloading the latest version of the official one and setting that as your OCIO config in Windows > Settings/Preferences > Preferences > Settings > Color Management over in Maya (nice labels Autodesk lol) and Edit > Preferences > Color Management over in Natron.
In Maya’s colour management settings the rendering space should be ACES - ACEScg and the display space should be ACES.
Now that these configs are synced to the regular standard ACES config you should notice your output transform options are a little different. Pick the one for your monitor, it’s probably sRGB if you’re on Windows or Linux… If you don’t know you should really find this out before doing anything else!
In Arnold’s render settings files should be written out as EXRs and Color Space should be set to “Raw”.
In Natron make sure the read node is set to ACEScg as both the File Colorspace and Output Colorspace (it’s not in your screenshot!). In your OCIO Display node the Input Colorspace should be set to ACEScg, the view transform (which should be configured for your monitor as mentioned above) should be set to the same one that you use in Maya (or any other OCIO enabled application).
Remember that when using the OCIODisplay node you need to set Natron’s built-in viewer transform (located beside the exposure & gamma sliders) to Linear(none) because Natron’s display transform settings are rather limited AFAIK and this only supports sRGB & REC709, once that’s all sorted it should give you no issues!
As always, if I’ve made any errors here please let me know and I’ll correct them 
As a bonus feature request / gripe, I’d love to see more robust integration of OCIODisplay into the viewer, the user experience of having to always place the node above the viewer in the graph for anything other than linearized images with 709 primaries → sRGB is kind of clunky.
Hank i agree with your workflow but with maya2022 you have three color transforms to match.
Rendering Space
Display Space
View Space
Here’s what those settings specifically should (most likely) look like for you when everything is set up using the instructions above:
I can explain the rationale behind each of these if you’d like, but these three transforms are actually the defaults when loading the actual ACES config… How convenient!
The important setting to note here (other than the view transform) is the “Apply Output Transform to Render” box which should be checked off. This is because we’ve set our rendering space to ACEScg and in our render settings we’ve told Arnold to dump that raw output right into the EXR and not apply any transformations so that we have all that data to work with over in Natron. If you’re only using ACES for your 3D rendering space and conforming to some other gamut for comp (don’t really know why you’d do this) this is the setting you’d change to make that happen.
The apply transform to playblast box is checked on so those will be rendered with the sRGB transform from the viewer, this way playblasts will look correct when they’re rendered to video files.
I trust the maya default on this one. Cause its from the same team they did OCIO 2.
Why should my display set to ACES?
Here is some more info about the setting in this Colorpicker Video from one of the Maya developers. Maybe it does help us to understand whats goin on.
Hmm looks like Natron cant load the maya OCIO 2 config file.
If you’re trying to work with ACES proper use the ACES configs from Colour Science, not the built in Maya ACES configs. It’s not really a matter of “trust” but rest assured that Thomas Mansencal (pipeline lead @ Weta) knows what he’s doing. The Arnold docs reference this config as well. This document does mention that new users are probably good with the default transforms, I disagree with this method as the whole point of OCIO is for users to manage their own unified colour pipeline settings independently of any single software package. For users that are looking to render in and not use ACES for the rest of their pipeline (or who are completely new to the scene and don’t understand colour management at all) this default config is fine, they can simply use the render transform method as mentioned above, that’s why it’s included… Also the software literally wouldn’t be colour managed without a config, they have to include something.
As for Natron compatibility, you’re correct in that it will not work with OCIO 2 specific features (Like the display transform box in Maya!) It’s almost like there are reasons behind these instructions or something…
In any case, I’ll reiterate again… go download the industry standard ACES config which includes far more output options that you will likely want when exporting your comps or final renders out of your NLE. It’s ALSO updated more frequently Follow the steps above, you’ll have a working ACES pipeline. It should be that simple?
ADDITIONALLY follow that repo closely for the ACES 1.3 update which will hopefully make its way over there sooner rather than later. They have fixed some pretty serious bugs in the latest update which I’ve been loosely following but haven’t tested myself yet.
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ACES 1.3 is running fine. I try to upgrade the pipeline to 1.4 but there is only the one from Maya compiled. Cause Autodesk is doing OCIO 2.
As we stuck here i wait until there is a solution.
The reason id like to go that route is cause most Artists here do not understand anything about color management. We need a out of the box solution without touching settings in maya.
The reason id like to go that route is cause most Artists here do not understand anything about color management. We need a out of the box solution without touching settings in maya.
Bad news is that this isn’t how OCIO is meant to be used (covered above) so any problems you have with this method are yours to deal with, sorry. I cannot help people who have a settings related issue if they refuse to change the setting. If you aren’t changing the default OCIO config to your global config (whatever that may be, maybe you prefer Filmic over ACES, that’s cool too) you’re not using OCIO in the way it is intended to be used.
ACES 1.3 is running fine. I try to upgrade the pipeline to 1.4 but there is only the one from Maya compiled. Cause Autodesk is doing OCIO 2.
What? ACES 1.3 came out 20 days ago, if you’ve found built configs for 1.4 (if that even exists) you absolutely shouldn’t be using those yet. Maya’s default config likely uses ACES 1.2 assuming they follow the VFX reference platform specs.
Thanks for bearing with me. I know im annoying.
I dont refuse to change settings but i want to change them only in Natron and my global setting is the one from maya.
I assume that wont work until Natron does read OCIO2 files. Im fine with that back to Maya2020.
https://opencolorio.readthedocs.io/en/latest/configurations/ocio_v2_demo.html
Thanks for your help!
Hey whatever works… Just so we’re all on the same page though, this absolutely works fine in Maya 2022 as long as you’re using the color-science ACES configs in both programs. If you want to use the default config in Maya 2020 as your OCIO config that will do whatever it does in both programs but at least your configs are synced!
In any case, hope you’ve been able to fix your issues and match your colors between programs! 
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Hi, sorry if I’m resurrecting a thread that should stay dead. I joined the forum because this post helped me with an issue I was having. But because I’m one of those people that doesn’t truly understand color management, I’m not sure which color space to use for some of my textures in Maya/Arnold. I converted a previous scene to the new color management settings you described here, but I’m getting errors for textures that used to be set to the Raw color space. Would Utility-Raw be the equivalent that I should use now? And what about the textures that used to be set to just sRGB? That color space doesn’t exist in the list any more.
Thanks again for this awesome info!
Everyone’s gotta start somewhere so no worries. I’m glad you found this information helpful!
Yes, textures that do not contain colour information (roughness, normals and the like) should indeed be set to Utility - Raw, I believe Role - data works the same way but only exists for OCIO features that I don’t personally use or really understand, for a description of why this exists see here.
sRGB encoded colour information needs to be moved into the ACES space as you know, so for that we use Utility - sRGB - Texture. It performs the same task as Maya’s default sRGB transform but is just labelled differently. If you have lots of these already set up in your files it may be worth scripting VS manually changing every file node over to the new name.
Hope this clears things up! 
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Thanks for the quick reply! I’m assuming HDRI’s should also be set to Utility - Raw if they were set to Raw in the previous system? That seems to give me good looking results so I hope it’s right.
Not quite. Your HDRIs are likely encoded with sRGB primaries and those need to be converted to ACES primaries. HDRIs do contain colour (light) data, they aren’t just arbitrary values that the render engine uses for material or position information like other raw data sources. Previously setting these to raw was probably fine as they are already linearized and you were likely rendering with the same RGB primaries (rec709/sRGB) as the HDRIs themselves. Now that you’ll be using AP1 primaries to render you gotta convert em.
I can already hear Tory getting mad about this so do note that this conversion process isn’t without it’s problems. I think ACES is interesting and I’m sympathetic to the problems they’re trying to solve but just know that it’s not yet a perfect system today from a technical perspective. 
The config option you want for these is probably going to be Utility - Linear - sRGB. Maya’s default config also has an option for this under a slightly different name.
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Brilliant thanks! It’s hard to find this info on other VFX forums, or they just give the answer but don’t explain why. I think I’ll stick around a bit
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