Houdini 22.0 Nodes Copernicus nodes

Laplacian Copernicus node

Computes the Laplacian of the source layer.

On this page
Since 22.0

This node computes the Laplacian of the source layer, which is the sum of the second derivatives along the layer’s width and height.

Parameters

Signature

The layer type that the source accepts.

See Signatures for more information.

Space

The space to compute the Laplacian in. This affects the magnitude of the result.

Image

Compute the Laplacian in Image Space, by normalizing the change in values by the image-space pixel size.

Pixel

Compute the Laplacian in Pixel Space, by normalizing the change in values by the pixel size.

Local

Compute the Laplacian in Local Space, by normalizing the change in values by the world-space pixel size.

Scale

Multiplies the source values before computing the Laplacian.

Read Pixels outside Image

Determines if derivatives at the boundary should read outside the image or restrict to the image range.

Turning this parameter on is useful when building seamless textures with a wrap border type. Turn this off if you want to avoid artificial flattening of the derivative at the boundary in a clamp border type, as it acts like an extrapolation.

Kernel Size

The distance (in buffer elements) to compute the derivatives used for the Laplacian.

A derivative is often computed with adjacent pixels, but if the values are slowly varying there may not be enough bit-depth to get smooth derivatives. Increasing this value may remove stepping artifacts from the result.

Inputs

source

The layer from which to compute the Laplacian.

Outputs

laplacian

The computed Laplacian. For multi-channel inputs, the Laplacian is computed for each channel.

See also

Copernicus nodes