IFC 4.3.x development

8.20.3.16 IfcSubedge

8.20.3.16.1 Semantic definitions at the entity

NOTE  Definition according to ISO/CD 10303-42:1992
A subedge is an edge whose domain is a connected portion of the domain of an existing edge. The topological constraints on a subedge are the same as those on an edge.

NOTE  Entity adapted from subedge defined in ISO 10303-42.

HISTORY  New entity in IFC2x2.

Informal Propositions:

  1. The domain of the subedge is formally defined to be the domain of the parent edge, as trimmed by the subedge start vertex and subedge end vertex.
  2. The start vertex and end vertex shall be within the union of the domains of the vertices of the parent edge and the domain of the parent edge.

8.20.3.16.1 Attributes

# Attribute Type Description
IfcRepresentationItem
LayerAssignmentSET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItemsAssignment 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.
IfcTopologicalRepresentationItem
IfcEdge
1 EdgeStart IfcVertex Start point (vertex) of the edge.
2 EdgeEnd IfcVertex End point (vertex) of the edge. The same vertex can be used for both EdgeStart and EdgeEnd.
IfcSubedge
3 ParentEdge IfcEdge The Edge, or Subedge, which contains the Subedge.

8.20.3.16.2 Entity inheritance

dot_inheritance IfcSubedge IfcSubedge IfcEdge IfcEdge IfcSubedge->IfcEdge IfcEdgeCurve IfcEdgeCurve IfcEdgeCurve->IfcEdge IfcTopologicalRepresentationItem IfcTopologicalRepresentationItem IfcEdge->IfcTopologicalRepresentationItem IfcOrientedEdge IfcOrientedEdge IfcOrientedEdge->IfcEdge IfcTopologicalRepresentationItem_children 6 more... IfcTopologicalRepresentationItem_children->IfcTopologicalRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcTopologicalRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.20.3.16.3 Formal representations

ENTITY IfcSubedge
 SUBTYPE OF (IfcEdge);
	ParentEdge : IfcEdge;
END_ENTITY;