Use an Adjacent Selection node () to create a selection of all entities of a given dimension that are adjacent to entities in a specified selection (having the same or another dimension). For example, it can select all boundaries adjacent to a given domain selection.

To add an Adjacent Selection node, select entities in the graphics, then choose one of the following:

Select the Level for the geometric entities: Domain, Boundary, Edge, or Point.

From the Input list, choose Select entities (default) to select entities by clicking in the Graphics or Selection List windows. The selected entities are added to the Input Entities section below and highlighted in the Graphics window. Choose From selections to use previously defined selections as input. Click the Add button () to open an Add dialog that contains all previously defined selections for the same geometric entity level. Select one or several of the selections and click OK; you can use the search bar to filter the list. Use the Delete () button to delete any selection from the list.

Based on space dimension, select a Geometric entity level: Domain, Boundary, Edge, or Point for the entities to add to the selection list or choose a named selection in the Selection list to refer to a previously defined selection.

Select and add geometric entities in the Graphics window or using other selection methods. The selected items are highlighted in the Graphics window.

If Boundary (for 2D and 3D components) or Edge is selected, also select the Group by continuous tangent checkbox to extend the selection to all adjacent faces or edges that have continuous tangents (an angle less than the value in the Angular tolerance field) at their junctions to select all faces that make up a continuous sheet, for example. When the Group by continuous tangent checkbox is selected, set the tolerance on the continuity condition in the Angular tolerance field as the maximum angle between two faces or edges that are considered as having continuous tangents (a value between 0 and 180 degrees; the default value is 5 degrees).

In the list, choose the type of output entities: Adjacent domains, Adjacent boundaries, Adjacent edges (3D only), or Adjacent points. If the dimension for the output entities one step lower dimension than the input entities, there are also two checkboxes that you can use to select exterior and interior entities of the union of the input selections.

By default, only exterior entities are selected. For example, if the input selections are domains selections, and the output is adjacent boundaries, the Exterior boundaries (selected by default) and Interior boundaries checkboxes display.

Select the Show in physics checkbox (selected by default) to make the resulting selection available as a named selection should appear in applicable settings for physics, materials, and other parts of the model tree outside of the mesh sequence or in instances of the mesh part. Clear the checkbox to keep the selection local to this mesh sequence.

In this section, choose a color from the Color list for use with this selection. See Selection Colors.