Constants

Environment Variables

These environmental variables are used by the OpenColorIO library (i.e. these variables are defined in src/OpenColorIO/Config.cpp).

PythonC++

PyOpenColorIO.OCIO_CONFIG_ENVVAR

The envvar ‘OCIO’ provides a path to the config file used by Config.CreateFromEnv

PyOpenColorIO.OCIO_ACTIVE_DISPLAYS_ENVVAR

The envvar ‘OCIO_ACTIVE_DISPLAYS’ provides a list of displays overriding the ‘active_displays’ list from the config file.

PyOpenColorIO.OCIO_ACTIVE_VIEWS_ENVVAR

The envvar ‘OCIO_ACTIVE_VIEWS’ provides a list of views overriding the ‘active_views’ list from the config file.

PyOpenColorIO.OCIO_INACTIVE_COLORSPACES_ENVVAR

The envvar ‘OCIO_INACTIVE_COLORSPACES’ provides a list of inactive color spaces overriding the ‘inactive_color_spaces’ list from the config file.

PyOpenColorIO.OCIO_OPTIMIZATION_FLAGS_ENVVAR

The envvar ‘OCIO_OPTIMIZATION_FLAGS’ provides a way to force a given optimization level. Remove the variable or set the value to empty to not use it. Set the value of the variable to the desired optimization level as either an integer or hexadecimal value. Ex: OCIO_OPTIMIZATION_FLAGS=”20479” or “0x4FFF” for OPTIMIZATION_LOSSLESS.

Roles

ColorSpace Roles are used so that plugins, in addition to this API can have abstract ways of asking for common colorspaces, without referring to them by hardcoded names.

Internal:

Extracting color space from file path - (ROLE_DEFAULT)

App Helpers:

ViewingPipeline         - (ROLE_SCENE_LINEAR (LinearCC for exposure))
                          (ROLE_COLOR_TIMING (ColorTimingCC))
MixingColorSpaceManager - (ROLE_COLOR_PICKING)

External Plugins (currently known):

Colorpicker UIs       - (ROLE_COLOR_PICKING)
Compositor LogConvert - (ROLE_SCENE_LINEAR, ROLE_COMPOSITING_LOG)

PythonC++

PyOpenColorIO.ROLE_DEFAULT

“default”

PyOpenColorIO.ROLE_REFERENCE

“reference”

PyOpenColorIO.ROLE_DATA

“data”

PyOpenColorIO.ROLE_COLOR_PICKING

“color_picking”

PyOpenColorIO.ROLE_SCENE_LINEAR

“scene_linear”

PyOpenColorIO.ROLE_COMPOSITING_LOG

“compositing_log”

PyOpenColorIO.ROLE_COLOR_TIMING

“color_timing”

PyOpenColorIO.ROLE_TEXTURE_PAINT

This role defines the transform for painting textures. In some workflows this is just a inverse display gamma with some limits.

PyOpenColorIO.ROLE_MATTE_PAINT

This role defines the transform for matte painting. In some workflows this is a 1D HDR to LDR allocation. It is normally combined with another display transform in the host app for preview.

PyOpenColorIO.ROLE_RENDERING

The rendering role may be used to identify a specific color space to be used by CGI renderers. This is typically a scene-linear space but the primaries also matter since they influence the resulting color, especially in areas of indirect illumination.

PyOpenColorIO.ROLE_INTERCHANGE_SCENE

The aces_interchange role is used to specify which color space in the config implements the standard ACES2065-1 color space (SMPTE ST2065-1). This may be used when converting scene-referred colors from one config to another.

PyOpenColorIO.ROLE_INTERCHANGE_DISPLAY

The cie_xyz_d65_interchange role is used to specify which color space in the config implements CIE XYZ colorimetry with the neutral axis at D65. This may be used when converting display-referred colors from one config to another.

Shared View

PythonC++

PyOpenColorIO.OCIO_VIEW_USE_DISPLAY_NAME

A shared view using this for the color space name will use a display color space that has the same name as the display the shared view is used by.

FormatMetadata

These constants describe various types of rich metadata. They are used with FormatMetadata objects as the “name” part of a (name, value) pair. All of these types of metadata are supported in the CLF/CTF file formats whereas other formats support some or none of them.

Although the string constants used here match those used in the CLF/CTF formats, the concepts are generic, so the goal is for other file formats to reuse the same constants within a FormatMetadata object (even if the syntax used in a given format is somewhat different).

PythonC++

PyOpenColorIO.METADATA_DESCRIPTION

A description string – used as the “Description” element in CLF/CTF and CDL, and to hold comments for other LUT formats when baking.

PyOpenColorIO.METADATA_INFO

A block of informative metadata such as the “Info” element in CLF/CTF. Usually contains child elements.

PyOpenColorIO.METADATA_INPUT_DESCRIPTOR

A string describing the expected input color space – used as the “InputDescriptor” element in CLF/CTF and the “InputDescription” in CDL.

PyOpenColorIO.METADATA_OUTPUT_DESCRIPTOR

A string describing the output color space – used as the “OutputDescriptor” element in CLF/CTF and the “OutputDescription” in CDL.

PyOpenColorIO.METADATA_NAME

A name string – used as a “name” attribute in CLF/CTF elements. Use on a GroupTransform to get/set the name for the CLF/CTF ProcessList. Use on an individual Transform (i.e. MatrixTransform, etc.) to get/set the name of the corresponding process node.

PyOpenColorIO.METADATA_ID

An ID string – used as an “id” attribute in CLF/CTF elements. Use on a GroupTransform to get/set the id for the CLF/CTF ProcessList. Use on an individual Transform (i.e. MatrixTransform, etc.) to get/set the id of the corresponding process node.

Caches

PythonC++

PyOpenColorIO.OCIO_DISABLE_ALL_CACHES

Disable all caches, including for FileTransforms and Optimized/CPU/GPU Processors. (Provided only to facilitate developer investigations.)

PyOpenColorIO.OCIO_DISABLE_PROCESSOR_CACHES

Disable only the Optimized, CPU, and GPU Processor caches. (Provided only to facilitate developer investigations.)

PyOpenColorIO.OCIO_DISABLE_CACHE_FALLBACK

By default the processor caches check for identical color transformations when cache keys do not match. That fallback introduces a major performance hit in some cases so there is an env. variable to disable the fallback.