Modifying the show grading space using looks

grading-space-looks-base.ocio

ocio_profile_version: 2.1

search_path:
  "grades/$SCENE/$SHOT/$ELEMENT:
  grades/$SCENE/$SHOT:
  grades/$SCENE:
  grades:
  luts:
  /my/global/config/location/luts/no-op"

environment:
  SCENE: ""
  SHOT: ""
  ELEMENT: ""

displays:
  Rec709:
    - !<View> {name: Show Look, colorspace: showLook}
    - !<View> {name: Show Look Graded, colorspace: showLook, looks: grade}

looks:
  - !<Look>
    name: grade
    process_space: Input - RED - REDLog3G10 - REDWideGamutRGB
    description: |
      The primary grade for this show.
    transform: !<FileTransform> {src: primary.cdl, direction: forward}

colourspaces:

  - !<ColorSpace>
    name: show_grading
    description: |
      Camera log space
    isdata: false
    from_reference: !<GroupTransform>
      children:
        - !<ColorSpaceTransform> {src: ACES - ACES2065-1, dst: Input - RED - REDLog3G10 - REDWideGamutRGB}

  - !<ColorSpace>
    name: showLook
    family: "Output"
    equalitygroup: ""
    bitdepth: 16ui
    description: |
      Simulation of show look output (contextual)
    isdata: false
    allocation: uniform
    allocationvars: [0.0, 1.0]
    from_reference: !<GroupTransform>
      children:
        - !<ColorSpaceTransform> {src: ACES - ACES2065-1, dst: show_grading}
        - !<FileTransform> {src: show_lut.cube, interpolation: tetrahedral}

grading-space-looks-input.ocio

ocio_profile_version: 2.1

looks:
  - !<Look>
    name: grade
    process_space: ARRI LogC3 (EI800)
    description: |
      The primary grade for this show.
    transform: !<FileTransform> {src: primary.cdl, direction: forward}

colourspaces:

  - !<ColorSpace>
    name: show_grading
    description: |
      Camera log space
    isdata: false
    from_reference: !<GroupTransform>
      children:
        - !<ColorSpaceTransform> {src: ACES - ACES2065-1, dst: ARRI LogC3 (EI800)}

Diff of base and merged configs:

% diff grading-space-look-base.ocio grading-space-look-merged.ocio 
24c24
<     process_space: Input - RED - REDLog3G10 - REDWideGamutRGB
---
>     process_space: ARRI LogC3 (EI800)
38c38
<         - !<ColorSpaceTransform> {src: ACES - ACES2065-1, dst: Input - RED - REDLog3G10 - REDWideGamutRGB}
---
>         - !<ColorSpaceTransform> {src: ACES - ACES2065-1, dst: ARRI LogC3 (EI800)}