IfcCurve

Natural language names
Kurve
Curve
Courbe
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:

  1. A curve shall be arcwise connected
  2. A curve shall have an arc length greater than zero.
Attribute definitions
#AttributeTypeCardinalityDescription G
Dim
:=IfcCurveDim(SELF)
IfcDimensionCountThe 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 IfcBoundedCurve IfcConic IfcLine IfcOffsetCurve IfcPcurve IfcPolynomialCurve IfcSpiral IfcSurfaceCurve IfcGeometricRepresentationItem IfcRepresentationItem
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRepresentationItem
LayerAssignmentIfcPresentationLayerAssignment
@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.
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.
X
StyledByItemIfcStyledItem
@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.
IFC2x3 CHANGE  The inverse attribute StyledByItem has been added.
X
IfcGeometricRepresentationItem
IfcCurve
Dim
:=IfcCurveDim(SELF)
IfcDimensionCountThe space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve. X
Formal representations
XML 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, IfcOffsetCurve, IfcPcurve, IfcPolynomialCurve, IfcSpiral, IfcSurfaceCurve))
 SUBTYPE OF (IfcGeometricRepresentationItem);
 DERIVE
  Dim : IfcDimensionCount := IfcCurveDim(SELF);
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

References  References: IfcGridAxis IfcSectionedSolid IfcSectionedSurface IfcSweptDiskSolid IfcGeometricSetSelect IfcCompositeCurveSegment IfcCurveBoundedPlane IfcCurveSegment IfcDirectrixCurveSweptAreaSolid IfcOffsetCurve IfcPcurve IfcPointByDistanceExpression IfcPointOnCurve IfcSurfaceCurve IfcTrimmedCurve IfcAnnotationFillArea IfcArbitraryClosedProfileDef IfcArbitraryProfileDefWithVoids IfcEdgeCurve

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