The Finalize feature (Form Union/Assembly) combines all available geometry objects in the sequence to form a single geometry object. In 2D and 3D you can modify this object by using virtual operations. The output of the last geometry feature is the finalized geometry used when meshing and when setting up physics. If the property action is set to union, and multiple geometry objects are present in the geometry sequence, the objects are combined into a single object with multiple domains corresponding to the input objects and overlaps between these. In a 1D and 2D axisymmetric geometry, the union action also removes the part of the geometry that falls in the region r<0.

Set the property action to assembly to keep multiple objects in the finalized geometry. Use this option when modeling physics that needs separate geometry objects, for example, when modeling mechanical contact.