Houdini 20.0 Nodes Geometry nodes

Glue Cluster geometry node

Adds strength to a glue constraint network according to cluster values.

On this page
Since 12.0

The Glue Cluster operator sets the strength attribute of a glue constraint network. If a point has a cluster value of zero, all polygons connected to the point will have the Cluster to Cluster Strength. Otherwise, if a polygon connects points of the same cluster attribute value, they will get the Internal Strength.

The optional incoming cluster attribute can be further refined with the Add Cluster Noise and Random Detach parameters.


Cluster Attribute

The name of the cluster attribute.

Internal Strength

The bond strength between two pieces in the same cluster.

Cluster to Cluster Strength

The bond strength between two pieces in different clusters.

Impact Propagations

When one of the objects is hit, its impact value is spread along the glue network. This allows distant glue bonds that are weak to be broken prior to nearer, strong bonds. The impact propagations is the number of rounds of propagation to do. Impulses will not travel more than this number of bonds each solve step.

Add Cluster Noise

Add cellular noise to any input points with a zero cluster attribute value.


The offset of the cellular noise added to the input points.


The size of the cells for the noise added to the input points. This roughly corresponds to the size of the clusters.


The jitter of the cellular noise added to the input points.

Random Detach

Randomly detach pieces from clusters.

Detach Seed

The random seed used for detachment.

Detach Ratio

The probability that a particular piece will be detached.

Visualize Cluster

Color the points randomly according to which cluster they belong to. Points with zero cluster will all get unique values. Usually you will want to use a Primitive SOP to copy this to the actual geometry.


Glue Network

A set of two-point polygons describing desired gluing between objects.


glueclusterexample Example for Glue Cluster geometry node

This example shows how to use the gluecluster SOP and glue constraint networks to cluster together the pieces of a voronoi fracture. This allows clustering to be used with Bullet without introducing concave objects.

Geometry nodes