Houdini 22.0 Nodes Copernicus nodes

UV Inverse Copernicus node

Computes the inverse of a UV distortion map.

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Since 22.0

This node creates the inverse of a UV distortion map. A UV distortion map is used by the Sample COPs to map from a texture into an image. The inverse map provides where to sample into the texture from the image given that map. This can be used to invert lens distortions.

Note often a distortion map is not invertible, with a texture coordinate mapping to more than one image location. The valid input can be used to restrict where inversion is computed.

Parameters

Space

The space the distortion map is in. A Texture distortion map is stretched to 0..1 range. An Image distortion map is fit to the -1..1 range.

Polish Iterations

Each valid pixel on the uv map is used as a seed by mapping it into the image space. Polish iterations improve the quality of this mapping by iterating the forward/backward maps.

Diffuse Iterations

Often many pixels in texture space have no equivalent in image space; a smooth fill is used to fill the gaps. This controls the number of iterations used, increasing will improve the quality of intermediate mapping values.

Inputs

size_ref

A representative layer that determines the size of the output image and controls the metadata.

uv

A UV distortion map, in either texture or image space, whose inverse is to be computed.

valid

A Mono layer identifying which pixels in the uv map contain valid mapping data. Pixels with a value less than 0.5 will be ignored.

Outputs

inverse

An inverse uv map. The Sample COPs can be used with this to construct a texture map from the result of having mapped the texture map with a Sample COP.

See also

Copernicus nodes