8.20.3.7 IfcFace
8.20.3.7.1 Semantic definition
An IfcFace is topological entity used to define surface, bounded by loops, of a shell.
Informal Propositions:
- No edge shall be referenced by the face more than twice.
- Distinct face bounds of the face shall have no common vertices.
- If geometry is present, distinct loops of the same face shall not intersect.
- The face shall satisfy the Euler Equation: (number of vertices) - (number of edges) - (number of loops) + (sum of genus for loops) = 0.
8.20.3.7.2 Entity inheritance
8.20.3.7.3 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 | |||
| IfcFace (2) | |||
| 1 | Bounds | SET [1:?] OF IfcFaceBound |
Boundaries of the face. |
| HasTextureMaps | SET [0:?] OF IfcTextureMap FOR MappedTo |
No description available. |
|
8.20.3.7.4 Formal propositions
| Name | Description |
|---|---|
| HasOuterBound |
At most one of the bounds shall be of the type IfcFaceOuterBound. |
|
|
8.20.3.7.5 Examples
8.20.3.7.6 Formal representation
ENTITY IfcFace
SUPERTYPE OF (ONEOF
(IfcFaceSurface))
SUBTYPE OF (IfcTopologicalRepresentationItem);
Bounds : SET [1:?] OF IfcFaceBound;
INVERSE
HasTextureMaps : SET [0:?] OF IfcTextureMap FOR MappedTo;
WHERE
HasOuterBound : SIZEOF(QUERY(temp <* Bounds | 'IFC4X3.IFCFACEOUTERBOUND' IN TYPEOF(temp))) <= 1;
END_ENTITY;