Houdini 20.0 Nodes Geometry nodes

RBD Constraints From Lines geometry node

Creates rigid body constraint geometry from interactively drawn lines in the viewport.

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Since 17.5


This node allows you to create and edit constraints between pieces in the viewport. It allows you to interactively draw constraints between the pieces you want to be connected. Once the constraint is drawn, you can choose the Connection Type to determine how the constraints are set up.

To...Do this

Create a new connection line

⇧ Shift + LMB drag.

Edit a connection line

MMB drag.

Delete a connection

⌃ Ctrl + LMB click the connection.

Edit hinge position

LMB drag the hinge.

Slide hinge position along the constraint line.

MMB drag along the line.

Switch between line and hinge tools

Press 1.

Switch between edit and transform handle

Press 2.



Input geometry to create constraints for.

Constraint Geometry

Constraint geometry to be merged with.

Proxy Geometry

Proxy geometry. The constraints will be built using this geometry when available.


Connection Type

Surface Points

Creates constraints connecting closest points from nearby pieces.


Creates 0 length 2 point prim constraints placed at the intersection of the 2 surfaces.

Center of Mass

Creates constraints connecting centroids of nearby pieces.

Hinge Length

Specify the length of the hinge constraint.

Group Type

Specifies how the created constraints should be grouped together. This can be used with the Constraint Group parameter on RBD Constraint Properties to easily alter specific constraints.

Group Name

Adds the created constraints to a primitive group with the specified name.


Assigns the specified name to the constraint_tag primitive attribute for each of the created constraints.

Clear Lines

Delete all drawn lines.

Clear Hinge Edits

Remove all hinge constraint edits.


RBDConstraints Example for RBD Constraints From Lines geometry node

This example demonstrates the use of the RBD Constraints from Lines, RBD Constraints from Curves and RBD Constraints from Rules SOPs.

See also

Geometry nodes