Houdini 20.5 Nodes Geometry nodes

Clip 2.0 geometry node

Removes or groups geometry on one side of a plane, or creases geometry along a plane.

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Since 20.5

You can use this node as a modeling tool, or to manually clip polygons outside the field of view to reduce scene complexity.

When Keep is not All primitives, this node attempts to clip all input primitives above or below the plane. If clipping would destroy the primitive’s structure (polygons, particle systems), the primitive is simply deleted.

Using Clip

  1. Select the object you want to to clip.

  2. Click the Clip tool on the Polygon tab.

  3. Specify the plane in which you would like the object to be clipped by moving the clip handle or clicking on the handle and choosing an axis in the align handle menu.

    This tool automatically clips half of the object. Moving the clip handle allows you to change how much of the object gets clipped.

Parameters

Group

Subset of the input geometry to clip.

Clip Attribute

The point attribute to clip. The default is the position attribute P. The geometry is clipped in 3D space, with the X, Y, and Z positions taken from the first three components of the Clip Attribute, respectively. Any unused components are set to zero. The clipping of a single-component attribute would thus be controlled by the plane’s intersection with the X-axis.

Keep

Primitives above the plane

Keep the geometry on the positive side of the plane, delete geometry on the other side.

Primitives below the plane

Keep the geometry on the negative side of the plane, delete geometry on the other side.

Keep All Primitives

Cut new edges into the input geometry along the plane, but do not delete geometry. Only polygons and polylines are cut by this operation.

Orient Plane with

Choose the set of parameters to orient the clipping plane with.

Direction

Orient the plane with an origin and direction.

Transform

Orient the plane with a translation and rotation.

Origin

Origin of the clipping plane.

Direction

Normal vector of the clipping plane.

Translate

Amount of translation of the clipping plane along the X,Y,Z axes.

Rotate

Amount of rotation of the clipping plane about the X,Y,Z axes.

Distance

Distance to translate the clipping plane along its normal.

Snapping Tolerance

Maximum distance to move points onto the plane.

Fill Polygons along Clipping Plane

Construct enclosing polygons from the clipped edges. When Keep is set to All Primitives, polygons will be split along the plane, and separate filled polygons will be constructed on either side.

Split Connectivity

When Keep is set to All Primitives, split the polygons along the plane so the above and below polygons are not connected.

Replace Existing

When on, replaces each existing group with the new group.

Clipped Edges

When on, adds the edges that lie on the plane to the group.

Clipped Primitives

When on, adds the remaining primitives that were clipped by the plane to the group.

Above Primitives

When Keep is set to All Primitives, adds the primitives that are above the plane to the group.

Below Primitives

When Keep is set to All Primitives, adds the primitives that are below the plane to the group.

Filled Polygons

When Fill Polygons Along Clipping Plane is on, adds the filled polygons to the group.

Examples

ClipParticle Example for Clip geometry node

This is a very basic example of how the Clip SOP can be used to control particle flow by cutting it with an infinite plane.

Play animation to see the effects.

ClipVariations Example for Clip geometry node

This network compares the various ways in which the Clip SOP can be used with geometry. Depending on what parts of the clipped geometry we want to keep, different effects are achievable.

The Clip SOP can also be used as a grouping tool by specify group boundaries with clip planes.

Clip planes can be animated. Play the animation to view the results.

See also

Geometry nodes