OCIONamedTransform

OCIONamedTransform uses the new NamedTransforms in the OCIO configs shipped with Nuke to emulate older methods of color management that ignored the RGB primaries and simply applied one-dimensional transformations. These NamedTransforms have been added to the config as sometimes it is helpful to include one or more transforms in a config that are essentially stand-alone transforms that do not have a fixed relationship to a reference space or a process space. An example would be a utility curve transform where the intent is to simply apply a LUT1D without any conversion to a reference space.

Note: There are a number of NDK examples covering OCIO workflows that ship with the Nuke developer documentation, which can be found here:
<install_directory>/Documentation/NDKExamples/Plugins/00b_8source.html

Inputs and Controls

Connection Type	Connection Name	Function
Input	unnamed	The image sequence to receive the colorspace conversion.
mask	An optional image to use as a mask. By default, the colorspace conversion is limited to the non-black areas of the mask. At first, the mask input appears as a triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Connection Type

Connection Name

Function

Input

unnamed

The image sequence to receive the colorspace conversion.

mask

An optional image to use as a mask. By default, the colorspace conversion is limited to the non-black areas of the mask.

At first, the mask input appears as a triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Control (UI)	Knob (Scripting)	Default Value	Function
OCIONamedTransform Tab
channels	channels	rgb	The transform is applied only to these channels. If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.
named transform	named_transform	none	Sets the named transform to apply to the input image. Select the family name first and then transform form the dropdown. For example, Input > ARRI > LogC3 - Curve (EI800). The transforms available are contained in the selected OCIO config file under the named_transforms: section.
mask	N/A	disabled	Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.
mask	maskChannelInput	none	The channel to use as a mask. By default, the colorspace conversion is limited to the non-black areas of this channel.
inject	inject	disabled	Copies the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.
invert	invert_mask	disabled	Inverts the use of the mask channel so that the colorspace conversion is limited to the non-white areas of the mask.
fringe	fringe	disabled	When enabled, only apply the effect to the edge of the mask. When disabled, the effect is applied to the entire mask.
(un)premult by	N/A	disabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
(un)premult by	unpremult	none	The image is divided by this channel before being processed, and multiplied again afterwards. If you are using premultiplied input images, you may want to check (un)premult by and select rgba.alpha here. This will simulate doing the color conversion before the premultiplication was done. It is the same as adding an Unpremult node before this node and a Premult node after, but allows you to work faster if you’re only using one color correct node. If you are using unpremultiplied input images, you should leave this set to none.
invert	invert_unpremult	disabled	Inverts the use of the (un)premultiply channel.
mix	mix	1	Dissolves between the original image at 0 and the full transform at 1.
Context Tab
key1	key1	n/a	Allows you to add variables to register certain viewer processes by creating a custom config.ocio and specifying the variable in the to_reference file transform. See Adding Context Viewer Processes for more information.
value1	value1	n/a
key2	key2	n/a
value2	value2	n/a
key3	key3	n/a
value3	value3	n/a
key4	key4	n/a
value4	value4	n/a