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

subedgedefined in ISO 10303-42.HISTORY New entity in IFC2x2.

Informal Propositions:

- 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.
- 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*.

# | Attribute | Type | Description |
---|---|---|---|

IfcRepresentationItem | |||

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. | |

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. |

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