IFC 4.3.x development

8.9.3.22 IfcCompositeCurveSegment

Change log

IFC4

additions where_rules ParentIsBoundedCurve
deletions where_rules WR1
modificationsattributes SameSense definitionChanged from boolean to IfcBoolean

IFC4X1

additionswhere_rulesParentIsBoundedCurve
deletionswhere_rulesParentIsBoundedCurve

IFC4X2

additionswhere_rulesParentIsBoundedCurve
deletionswhere_rulesParentIsBoundedCurve

IFC4X3_RC3

additions where_rulesParentIsBoundedCurve
deletions attributes Transition
deletions inverses UsingCurves
deletions where_rulesParentIsBoundedCurve
modificationssupertype Changed from IfcGeometricRepresentationItem to IfcSegment

8.9.3.22.1 Semantic definitions at the entity

An IfcCompositeCurveSegment is a bounded curve constructed for the sole purpose to be a segment within an IfcCompositeCurve.

NOTE  Definition according to ISO/CD 10303-42:1992
A composite curve segment is a bounded curve together with transition information which is used to construct a composite curve.

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

HISTORY  New entity in IFC1.0

8.9.3.22.1 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.
IfcCompositeCurveSegment
2 SameSense IfcBoolean An indicator of whether or not the sense of the segment agrees with, or opposes, that of the parent curve. If SameSense is false, the point with highest parameter value is taken as the first point of the segment.

> NOTE  If the datatype of ParentCurve is IfcTrimmedCurve, the value of SameSense overrides the value of _IfcTrimmedCurve.SenseAgreement_
3 ParentCurve IfcCurve The bounded curve which defines the geometry of the segment.
Dim INVALID The space dimensionality of this class, defined by the dimensionality of the first ParentCurve.

8.9.3.22.2 Entity inheritance

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

8.9.3.22.3 Formal representations

ENTITY IfcCompositeCurveSegment
 SUPERTYPE OF (ONEOF
	(IfcReparametrisedCompositeCurveSegment))
 SUBTYPE OF (IfcSegment);
	SameSense : IfcBoolean;
	ParentCurve : IfcCurve;
 DERIVE
	 Dim : IfcDimensionCount := ParentCurve.Dim;
 WHERE
	ParentIsBoundedCurve : ('IFC4X3_DEV_a1492713.IFCBOUNDEDCURVE' IN TYPEOF(ParentCurve));
END_ENTITY;