8.20.3.2 IfcClosedShell
8.20.3.2.1 Semantic definition
Informal Propositions:
- Every edge shall be referenced exactly twice by the loops of the face.
- Each oriented edge shall be unique.
- No edge shall be referenced by more than two faces.
- Distinct faces of the shell do not intersect, but may share edges or vertices.
- Distinct edges do not intersect but may share vertices.
- Each face reference shall be unique.
- The loops of the shell shall not be a mixture of poly loop and other loop types. Note: this is given, since only poly loop is defined as face bound definition.
- The closed shell shall be an oriented arcwise connected 2-manifold.
- The Euler equation shall be satisfied. Note: Please refer to ISO 10303-42 for the equation.
8.20.3.2.2 Entity inheritance
8.20.3.2.3 Attributes
| # | Attribute | Type | Description |
|---|---|---|---|
| IfcRepresentationItem (2) | |||
| LayerAssignment | SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems |
Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items. |
|
| StyledByItem | SET [0:1] OF IfcStyledItem FOR Item |
Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. |
|
| Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes | |||
| IfcConnectedFaceSet (1) | |||
| 1 | CfsFaces | SET [1:?] OF IfcFace |
The set of faces arcwise connected along common edges or vertices. |
8.20.3.2.4 Examples
8.20.3.2.5 Formal representation
ENTITY IfcClosedShell
SUBTYPE OF (IfcConnectedFaceSet);
END_ENTITY;