Boolean selections — Union (
),
Intersection (
),
Difference (
), and
Complement (
) — are useful to combine two or more selections (union), create a selection of overlapping geometric entities (intersection), create selection of entities that are in one selection but not in another (difference), and to create a selection as the inverse (complement) of one or more selections (all boundaries except the inflow boundaries, for example). The complement can be convenient if a selection is needed that consists of all boundaries except one or a few. Then it is easier to first create a selection (just the one boundary, for example) and then use a
Complement node to create its complement. All Boolean selection nodes’
Settings windows have similar sections. To add this node, right-click the
Definitions node and choose an option from the
Selections menu.
Based on space dimension, select a Level —
Domain,
Boundary,
Edge (3D only), or
Point for the selections to add or remove from the
Selections to add (
Selections to intersect,
Selections to subtract,
Selections to invert) list.
Use the buttons in this section to move, add, or delete selections in the Selections to add (Union),
Selections to intersect (Intersection), or
Selections to invert (Complement) lists. For the
Difference selection node also choose
Selections to subtract. Click the
Add button (
) to open an
Add dialog box that contains all existing selections for the same geometric entity level. Use the
Move Up (
),
Move Down (
), and
Delete (
) buttons to organize the list.
