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Authoring the Open Color IO Configuration

This article will show you how to set the OCIO config file for a new project.

Establishing the Color Workflow in Text Form​

The color workflow for a project can be found in two places, the OCIO (which is a text based version of the operations) and in the Render Template. In the OCIO, it is under the "Shot Look" section of the file and looks like this:

  - !<Look>
    name: Shot Look
    process_space: ACEScg
    transform: !<GroupTransform>
      children:
        - !<ColorSpaceTransform> {src: ACES2065-1, dst: ACEScg}  # Convert ACES Interchange to linear
        - !<ColorSpaceTransform> {src: ACEScg, dst: ARRI LogC3 (EI800)}  # Convert linear to ARRI LogC3
        - !<FileTransform> {src: "$CDL_PATH", cccid: 0, interpolation: linear}  # Apply the shot-specific look cdl or neutral if no cdl
        - !<FileTransform> {src: "$LUT_PATH", interpolation: linear}  # Apply Sequence Dependent LUT
info

This code block can be found by searching "Shot" in the default ocio config in P:\Admin\resources\ocio\baked_fn-nuke_studio-config-v1.0.0_aces-v1.3_ocio-v2.1.ocio

It's a bit confusing at first glance, but if you read it carefully, it's mostly in plain english. The 'children' are basically just the node stack you'd usually find in a nuke script and details the different operations. 9/10 times, you're just adjusting these "children" sections.

The $SHOT_CUBE token allows for specific cdl ids to switch out depending on the shot context.

In the Render Template​

The other place you'll find the color workflow is in the Render Template in a group node called COLOR. In there you should put a OCIO Look Transform node which gets picked up at render to be context specific - it should point to the Look used in your OCIO.

Testing the OCIO Config​

When you're all set, you can test the OCIO by looking at your viewer in a nuke script in that project and shot environment. You can also reach out to a coordinator and ask them to generate a v000.