IFC 4.3.0.1 (IFC4X3_TC1)

8.20.3.11 IfcLoop

8.20.3.11.1 Semantic definition

Image where V and E~l~ are the number of unique vertices and oriented edges in the loop and G^l^ is the genus of the loop.
Figure 8.20.3.11.A

Informal Propositions:

  1. A loop has a finite extent.
  2. A loop describes a closed (topological) curve with coincident start and end vertices.

8.20.3.11.2 Entity inheritance

8.20.3.11.3 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.

Table 8.20.3.11.B

8.20.3.11.4 Formal representation

ENTITY IfcLoop
 SUPERTYPE OF (ONEOF
	(IfcEdgeLoop
	,IfcPolyLoop
	,IfcVertexLoop))
 SUBTYPE OF (IfcTopologicalRepresentationItem);
END_ENTITY;

8.20.3.11.5 References