Houdini 20.0 Nodes Geometry nodes

PolyCut geometry node

Breaks curves where an attribute crosses a threshold.

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Since 13.0

This node allows you to break curves by deleting points, deleting edges, or splitting edges where an attribute crosses a threshold.

Parameters

Polygon Group

The group of polygons to operate on.

Type

Specifies whether the curve should be broken by manipulating Points or Edges.

Cut Points

The group of points that may be removed or cut when Type is Points.

Cut Edges

The group of edges that may be removed or cut when Type is Edges.

Strategy

Specifies how the curve will be broken when an invalid edge is found. Invalid edges are determined using the Cut Attribute, Cut Value, and Cut Threshold values. If the Cut Attribute is not specified, all edges are considered invalid.

The Cut Points and Cut Edges groups allow you to limit which points or edges are affected.

Remove

When Type is Points and an invalid edge is found, both endpoints of the edge are deleted (along with the adjacent edges).

When Type is Edges and an invalid edge is found, the edge is deleted.

Cut

When Type is Points and an invalid edge is found, the curve is cut at the two endpoints of the edge.

When Type is Edges and an invalid edge is found, the polygon is cut partway along that edge (the cut location is determined using the Detect Edge Changes setting).

Detect Edge Changes

Specifies how invalid edges are found.

Cut At Attribute Crossing

If the Cut Attribute crosses the Cut Value, the edge will be removed or cut. If the Cut Attribute is equal to the Cut Value for both of the edge’s points, the edge will also be removed but will not be cut.

If the edge is being cut, the location of the cut along the edge is determined by linearly interpolating to find where the Cut Attribute crosses the Cut Value.

Cut At Attribute Change

If the Cut Attribute changes by more than the Cut Threshold, the edge will be removed or cut.

If the edge is being cut, the edge will be divided into multiple shorter edges where the Cut Attribute changes by no more than the Cut Threshold.

Cut Attribute

The attribute used to determine whether edges are valid or should be cut.

Cut Value

A threshold value for the Cut Attribute. This is used when Detect Edge Changes is Cut At Attribute Crossing.

Cut Threshold

The maximum amount that the Cut Attribute may change by from one point to the next. If the Cut Attribute is a vector, the length between the two vectors will be computed. This is used when Detect Edge Changes is Cut At Attribute Crossing.

Keep Polygons Closed

Toggles whether or not the resulting fragments of a polygon will be closed if the original polygon is closed.

Examples

PolyCutBasic Example for PolyCut geometry node

This is a simple example of some different ways that the PolyCut SOP can be used to break curves based on attribute changes.

See also

Geometry nodes