Houdini 20.5 Nodes Copernicus nodes

Mono Copernicus node

Convert a layer to Mono.

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This operation converts a layer into a Mono layer. This is often done with a form of luminance computation, of which this provides several. But this can also be used to extract a particular channel, grab the maximum or minimum, or the of the channels treated as a vector.

Note for extracting a channel, Channel Extract COP may be better.

Parameters

Signature

The layer type that the source accepts.

See Signatures for more information.

Operation

The method to combine the source channels into the final value. The standard channel extension rules apply if necessary, unless specified otherwise.

Some luminance methods assume a source colour space - no implicit conversion will be done from your scene_linear to this space.

SGI Luminance

This is a historical luminance computation used in Houdini, which is believed to originate with SGI.

lum = 0.3086 * red + 0.6094 * green + 0.0820 * blue

NTSC Luminance

The standard NTSC luminance computation. This is probably the most commonly used luminance options.

lum = 0.299 * red + 0.587 * green + 0.114 * blue

HDTV Luminance

The HDTV standard luminance from BT 709.

lum = 0.2126 * red + 0.7152 * green + 0.0722 * blue

Average

An average of the channels.

Maximum Channel

The maximum of the channels.

Minimum Channel

The minimum of the channels.

Magnitude / Length

The length of the vector formed by taking the channels as components. For Mono input, this is the absolute value.

Hue

Convert to HSV and return the hue channel.

Saturation

Convert to HSV and return the saturation channel.

Value

Convert to HSV and return the value channel.

Red

Extract the red, or x, channel

Green

Extract the green, or y, channel

Blue

Extract the blue, or z, channel

Alpha

Extract the alpha, or w, channel

Custom

Perform custom weighting of the channels. If you want this weighting to vary per pixel, the Dot Product COP can be used.

Weights

The weight to multiply each of the channels by before adding them up to get the luminance.

Normalize Weights

If set, the weights provided will be scaled by their total to ensure the total comes to one.

Inputs

source

The layer to convert to Mono. It can be Mono, UV, RGB, or RGBA.

Outputs

mono

The Mono layer created by combining the source values into a single channel.

See also

Copernicus nodes