Custom View Transform in OCIO config in Maya Arnold

Hi everyone
Let me explain my problem ))
Before using ACES in Maya, I used to use my custom LUT during the whole production process. We have color grading and all 3D production from ` Texturing, Shading, Lighting and render we do using that LUT. And finishing all in nuke,also using that final grading.
So, after testing ACES workflow,I noticed that when I turn on OCIO config in maya color management, it automatically lock ADD button in View transform, so I got a problem adding my custom Lut.
Please people, if someone knows how can I solve the problem and show the way of changing the OCIO config please help with some tutorial :slight_smile:
Thanks a lot
Best regards

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Welcome Khcho, and thanks for your first post!
Looking forward to someone (with more experience than me!) with Maya to help you out.

Steve T
ACESCentral Admin

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what about configure your custom lut directly into a custom modified config of the aces config?
just define a new colorspace with a “file transform” from i.e. “utility - linear - srgb” to “your lut file”…then append this colorspace to your ODTs list.
of course your lut is intended to work on a specific colorspace input (assuming linear with srgb primaries)…

edit: just saw that you need directions on how to modify the config file…on the ocio homepage there is a good documentation about config files and how to customize them…(its not so complicated)…or just by looking to the existing aces config with a text editor and examin the colortransform+filetransform syntax as well as the display+view syntax

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Hello everybody,

I also tried to make a custom config OCIO File for the same purpose but was not very successfull. I tried duplicating the default config file and adding a new color space based on an existing one using a text editor as suggested but always ended with a corrupted config file. Nuke was never able to read the new file.
Maybe it’s better to use the proper “generate_config.py” but I was not able to find a good source explaining how to use it, even not on the OpenColorIO homepage.

It would be much appreciated if someone could expain, step by step, the right way to customize the config file for i.e. adding an extra colorspace driven by a custom LUT file.

Thanks a lot!
Cheers,
Andrei

Hi @NAD

there has been a discussion to do a step-by-step OCIO config documentation on the OCIO website. Have you looked at the actual OCIO documentation ?

Thanks,
Chris

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Welcome @NAD,

I would not recommend trying to run the generator, it is a can of worm you might not want to dive into. Take a look at this commit from the Gamut Mapping VWG to get an idea on how to add some new Views with custom LUTs: https://github.com/colour-science/OpenColorIO-Configs/commit/5d2b00ed255ed0b4c4d56610173de9dd599012a5

Cheers,

Thomas

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i am doing this all the time using notepad++
adding .cube files…
i think your idents maybe wrong?
i normally copy paste an existing colorspace with all the idents and modify it…
the same goes for the view syntax and display…

you have to put your LUT file into the lut folder, then with the filetransform syntax the name of that lut-file…

on what colorspace should your lut work?

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Indeed, it is worth noting that YAML is very strict about indentation, that is what defines the document structure, like Python for example.

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Hello to all,

I finally had the time to check out all the great suggestions you made and it worked like a charm.

Special Thanxs @Thomas_Mansencal for pointing me to the github source. Using this reference I got an idea how this works and only had to figure out what additional Transforms I had to add to get the proper result.

I used notepad++ as suggested

Thank you all for your help

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