Selection Terminology A selection represents a set of entities on an entity dimension or geometric entity level. A boundary selection is a selection with the geometric entity level boundary. For a boundary selection in 3D the set of entities is face numbers and the entity dimension is 2. In 2D, a boundary selection has a set of edge numbers and the entity dimension is 1. There are no edge selection in 2D and 1D, and no point selection in 1D, because there are redundant with the boundary selection. The table below summarizes the geometric entity levels and their entity dimensions. level Dimension3D Dimension2D, 2D axisymmetric Dimension 1D, 1D axisymmetric Dimension0D or global Domain 3 2 1 N/A Boundary 2 1 0 N/A Edge 1 N/A N/A N/A Point 0 0 N/A N/A Global -1 -1 -1 -1 2. The geometric entity type, or just entity type, is a category in which each entity in a set belongs to. Usually, the physics interface selection defines in what entity types an entity in a set belongs to. Below is a short summary of all entity types available for features and selections. Entity Type Applies to Level(s) Description Active All levels Entities where the physics interface is active Inactive All levels Entities where the physics interface is inactive Geometry All levels Same as Active Exterior Boundary Entities that are exterior to the physics interface selection Interior Boundary Entities that are interior to the physics interface selection Symmetry axis Boundary, Edge, Point Only for axial symmetry. The entities that lies on the symmetry axis (z-axis) Pair Boundary, Edge, Point Not used by entities. For a Feature it means that the program creates an automatic version for pairs. Source or destination Boundary, Edge, Point Not used by entities. For a Feature it means it only applies as a fallback feature for pairs Exterior, neither source nor destination Boundary Not used by entities. For a Feature it means that it is excluded from the list of fallback features for pairs Neither source nor destination Edge, Point Same as the previous row for edges and points Identity pair Boundary, Edge, Point For future use Contact pair Boundary, Edge, Point For future use Only a subset of these makes sense for a selection, and some are not used at all by the Physics Builder.
