Houdini 20.5 Nodes Geometry nodes

Attribute Transform Compute geometry node

Computes transform matrices using vector and matrix point attributes.

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Since 19.0

This SOP provides an interface to take vector and matrix point attributes such as those created by the Attribute Transform Extract SOP, and use them to compute transform matrices. The node interprets these vectors and matrices as the results of one of two transform matrix decompositions and then uses them to reconstruct the matrix.

The two decomposition which can be reversed are polar decompositions and the process of cracking transform matrices. These are the same decompositions methods which can be performed by the Attrib Transform Extract SOP.

In 'Polar Decomposition' mode, translation and rotation vectors can be specified as well as a stretch matrix.

When the 'Crack Transform' decomposition mode is selected, translation, rotation, scale, and shear vectors can be specified.

If any component is not selected or is missing, then the matrix will be constructed without that component.

Tip

You can easily remove components from matrices by extracting each of the components with the Attribute Transform Extract SOP and then recomputing the matrix with only the desired components using this SOP.

Parameters

Group

Specifies which points will have their matrices re-computed.

Transform

These parameters manage what matrix point attributes to decompose and how they should be decomposed.

Decomposition

The decomposition method which is reversed to compute the matrices.

Polar Decomposition

A polar decomposition will be reversed to compute the matrix attributes. Translation vectors, rotation vectors, and 3×3 stretch matrices can be used to compute the matrices.

Crack Transform

The matrix attributes will be computed by treating the components as if they were obtained from cracking the matrix. Translation, rotation, scale, and shear vectors can be used to compute the matrices.

Transform Order

Order in which the transformations occur to compute the matrices.

Rotation Order

Order in which the rotations occur to compute the matrices.

Attributes

The matrix attributes to be computed.

Translation

The prefix and suffix of the translation vector attributes which are used to compute the matrix. Translation attributes will only be used when computing 4×4 matrices.

For example, if the localtransform 4×4 matrix attribute is being computed, the translation prefix is _ and the suffix is _t, the translation attribute should be _localtransform_t.

Rotation

The prefix and suffix of the rotation vector attributes which are used to compute the matrices. The rotations should be specified in degrees.

Stretch

The prefix and suffix of the 3×3 stretch matrix attributes which are used to compute the matrices.

This parameter is only available when Decomposition is set to Polar Decomposition.

Scale

The prefix and suffix of the scale vector attributes which are used to compute the matrices.

This parameter is only available when Decomposition to Reverse is set to Crack Transform.

Shear

The prefix and suffix of the shear vector attributes which are used to compute the matrices.

This parameter is only available when Decomposition is set to Crack Transform.

Inputs

Geometry to Process

The geometry with matrix point attributes to compute.

Outputs

Geometry with Computed Transforms

The geometry with re-computed matrix point attributes.

See also

Geometry nodes