IFC 4.3.x development

8.20.3.18 IfcVertex

8.20.3.18.1 Semantic definitions at the entity

NOTE  Definition according to ISO/CD 10303-42:1992
A vertex is the topological construct corresponding to a point. It has dimensionality 0 and extent 0. The domain of a vertex, if present, is a point in m dimensional real space R^M^; this is represented by the vertex point subtype.

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

HISTORY  New entity in IFC2.0

Informal Propositions:

  1. The vertex has dimensionality 0. This is a fundamental property of the vertex.
  2. The extent of a vertex is defined to be zero.

# 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.

8.20.3.18.1 Entity inheritance

dot_inheritance IfcVertexPoint IfcVertexPoint IfcVertex IfcVertex IfcVertexPoint->IfcVertex IfcTopologicalRepresentationItem IfcTopologicalRepresentationItem IfcVertex->IfcTopologicalRepresentationItem IfcTopologicalRepresentationItem_children 6 more... IfcTopologicalRepresentationItem_children->IfcTopologicalRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcTopologicalRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.20.3.18.2 Formal representations

ENTITY IfcVertex
 SUPERTYPE OF (ONEOF
	(IfcVertexPoint))
 SUBTYPE OF (IfcTopologicalRepresentationItem);
END_ENTITY;