8.8.3.17 IfcFaceBasedSurfaceModel

8.8.3.17.1 Semantic definition

The IfcFaceBasedSurfaceModel represents the a shape by connected face sets. The connected faces have a dimensionality 2 and are placed in a coordinate space of dimensionality 3.

Informal Propositions

The connected face sets shall not overlap or intersect except at common faces, edges or vertices.
The fbsm faces have dimensionality 2.

8.8.3.17.2 Entity inheritance

8.8.3.17.3 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. IFC2x3-CHANGE The inverse attribute LayerAssignments has been added. IFC4-CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
	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. IFC2x3-CHANGE The inverse attribute StyledByItem has been added.
Click to show 2 hidden inherited attributes
IfcFaceBasedSurfaceModel (2)
1	FbsmFaces	SET [1:?] OF IfcConnectedFaceSet	The set of connected face sets comprising the face based surface model.
*	Dim	IfcDimensionCount	This attribute is formally derived. `3` The space dimensionality of this class, it is always 3.

Table 8.8.3.17.B

8.8.3.17.4 Examples

Figure 8.8.3.17.A

Surface Model

8.8.3.17.5 Formal representation

 ENTITY IfcFaceBasedSurfaceModel
 SUBTYPE OF (IfcGeometricRepresentationItem);
	FbsmFaces : SET [1:?] OF IfcConnectedFaceSet;
 DERIVE
	 Dim : IfcDimensionCount := 3;
END_ENTITY;

8.8.3.17 IfcFaceBasedSurfaceModel

8.8.3.17.1 Semantic definition

8.8.3.17.2 Entity inheritance

8.8.3.17.3 Attributes

8.8.3.17.4 Examples

8.8.3.17.5 Formal representation

8.8.3.17.6 References

8.8.3.17.7 Changelog

8.8.3.17.7.1 IFC4

8.8.3.17.7.2 IFC4.2

	ENTITY IfcFaceBasedSurfaceModel
	SUBTYPE OF (IfcGeometricRepresentationItem);
	FbsmFaces : SET [1:?] OF IfcConnectedFaceSet;
	DERIVE
	Dim : IfcDimensionCount := 3;
	END_ENTITY;