Houdini 20.5 Nodes Geometry nodes

Guide Interpolation Mesh geometry node

Given a set of guide curves and a skin mesh, generates a mesh that can be used to interpolate guide curve influences at any point.

Generates a low resolution mesh, encoding the influence of each guide a pair of index & weight array attributes.

Root points of guides are inserted into the skin mesh. These points are kept in the skin geometry as hard reference points, while the rest of the geometry may be remeshed to a fairly low resolution. Points on the mesh that don’t represent a guide are then assigned weights using a biharmonic function. This results in smooth blending of guide weights across the entire mesh.

Parameters

Guide Group

The group of guides to use.

Mask

A mask defining where the mesh needs to be generated. When used for grooming, this is usually the same as a density or length mask used for generating hair.

None

Don’t use any mask. A mesh will be generated for the entire geometry.

Skin Attribute

Use a skin attribute to supply mask values.

Texture

Use a texture image on disk to supply mask values.

Texture Primitive

Use a texture primitive from the Volume input to supply mask values.

Mask Attrib

The mask attribute when Mask is set to Skin Attribute.

Mask Texture

The texture file to use when mask is set to Texture.

Mask Texture

The name of the primitive to use when Mask is set to Texture Primitive.

Mesh

Remesh

Remesh the skin geometry, usually to a lower resolution. This mostly applies to areas that have a fairly sparse guide distribution. In these areas it is often enough to have a mesh resolution far lower than the original skin’s.

Iterations

The number of remesh iterations to perform. More iterations can results in smooth mesh output.

Require Max Triangle Size

Constrain triangles to a maximum size, measured by edge length.

Max Triangle Size

The largest edge length allowed on generated triangles.

Require Minimum Triangle Size

Keep triangles above a minimum size, measured by edge length.

Minimum Size from Guide Distances

Automatically compute a suitable minimum size from the guide curve distribution.

Percentile of Guide Distances

When Minimum Size from Guide Distances is enabled, this is the percentile of guide distances to use as minimum triangle edge length.

Min Triangle Size

The minimum edge lengths allowed in generated triangles. This is used Minimum Size from Guide Distances is disabled.

Remesh Sequence

This allows you to change the order in which remeshing & guide point insertion are performed.

Note

The effects of this can be fairly subtle, but depending on the input one method or another can produce substantially better results.

Before Adding Guides (Best Interactivity)

Remeshing will occur before guide root points are added into the mesh.

Before and After Adding Guides

Remeshing occurs both before and after guide root points are added into the mesh.

After Adding Guides (Best Quality)

Remeshing occurs after guide root points are added into the mesh.

Solve

Max Solve Iterations

Maximum iterations to compute the biharmonic function. If results are within the Solve Tolerance before the maximum is reached, the loop is stopped early.

Solve Tolerance

The solve tolerance to aim for with the biharmonic weight function. When computed values fall within this threshold the computation is stopped.

Guide Attributes

Interpolate Guide Attributes

Interpolate additional guide attributes, transferring the blended value to the generated mesh.

Primitive Attributes

The list of guide primitive attribute to transfer to the mesh.

Index Attrib

The name of the index attribute to output. This stores the list of guides each mesh points references.

Weight Attrib

The name of the weight atttribute to output. This stores the weight of each guide a point references.

See also

Geometry nodes