IFC 4.3.x development

8.9.3.62 IfcSegment

Change log

IFC4X3_RC3

added

8.9.3.62.1 Semantic definitions at the entity

Definition of a curve segment with a trimming mechanism built in with a StartPlacement (first point) and SegmentLength (second point).

8.9.3.62.1 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.
IfcGeometricRepresentationItem
IfcSegment
1 Transition IfcTransitionCode Connectivity between the continuous segments is not enforced per se to be tangential. Setting "TangentialContinuity" to True means that the current segment shall continue with tangential continuity to the previous one.
UsingCurves SET [1:?] OF IfcCompositeCurve FOR Segments The set of composite curves which use this composite curve segment as a segment. This set shall not be empty.

8.9.3.62.2 Entity inheritance

dot_inheritance IfcCompositeCurveSegment IfcCompositeCurveSegment IfcSegment IfcSegment IfcCompositeCurveSegment->IfcSegment IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcSegment->IfcGeometricRepresentationItem IfcCurveSegment IfcCurveSegment IfcCurveSegment->IfcSegment IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.9.3.62.3 Formal representations

ENTITY IfcSegment
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcCompositeCurveSegment
	,IfcCurveSegment))
 SUBTYPE OF (IfcGeometricRepresentationItem);
	Transition : IfcTransitionCode;
 INVERSE
	UsingCurves : SET [1:?] OF IfcCompositeCurve FOR Segments;
END_ENTITY;