IfcCurve

Semantic definitions at the entity

Entity definition

An IfcCurve is a curve in two-dimensional or three-dimensional space. It includes definitions for bounded and unbounded curves.

NOTE Definition according to ISO 10303-42:
A curve can be envisioned as the path of a point moving in its coordinate space.

NOTE Entity adapted from curve defined in ISO 10303-42

HISTORY New entity in IFC1.0

Informal Propositions:

A curve shall be arcwise connected
A curve shall have an arc length greater than zero.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
	Dim :=IfcCurveDim(SELF)	IfcDimensionCount	[1:1]	The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @AssignedItems	S[0:1]	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.	X
	StyledByItem	IfcStyledItem @Item	S[0:1]	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.	X
IfcGeometricRepresentationItem
IfcCurve
	Dim :=IfcCurveDim(SELF)	IfcDimensionCount	[1:1]	The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.	X

Formal representations

XSD Specification

 <xs:element name="IfcCurve" type="ifc:IfcCurve" abstract="true" substitutionGroup="ifc:IfcGeometricRepresentationItem" nillable="true"/>

 <xs:complexType name="IfcCurve" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:IfcGeometricRepresentationItem"/>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcCurve

 ABSTRACT SUPERTYPE OF(ONEOF(IfcBoundedCurve, IfcConic, IfcLine, IfcOffsetCurve2D, IfcOffsetCurve3D, IfcPcurve))

 SUBTYPE OF (IfcGeometricRepresentationItem);

 DERIVE

  Dim : IfcDimensionCount := IfcCurveDim(SELF);

END_ENTITY;

 EXPRESS-G diagram

	Kurve
	Curve
	Courbe