IfcCircularArcSegment2D

Natural language names
Circular Arc Segment 2D
Change log
ItemSPFXMLChangeDescription
IFC4x1 Release Candidate 1
    IfcCircularArcSegment2DADDED
IFC4x2 FINAL
    IfcCircularArcSegment2D
      PositioningElementADDED
Semantic definitions at the entity
Entity definition

The circular arc segment uses the inherited attributes StartPoint as the start of the circular arc, StartDirection as the tangent at the start point and SegmentLength as the arc length.

 

Figure 370 — Circular arc segment 2D

Figure 371 — Circular arc segment 2D CCW

Attribute definitions
#AttributeTypeCardinalityDescription G
4RadiusIfcPositiveLengthMeasure The radius of the circular arcX
5IsCCWIfcBoolean (counter-clockwise or clockwise) as the orientation of the circular arc with Boolean=”true” being counter-clockwise, or “to the left", and Boolean=”false” being clockwise, or “to the right”.X
Inherited definitions from supertypes
Entity inheritance IfcCurveSegment2D IfcBoundedCurve IfcCurve 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
IfcBoundedCurve
PositioningElementIfcLinearPositioningElement
@Axis
? X
IfcCurveSegment2D
1StartPointIfcCartesianPoint The start point of the 2D curve as x/y coordinates defined by a 2D Cartesian point.X
2StartDirectionIfcPlaneAngleMeasure The direction of the tangent at the start point. Direction value 0. indicates a curve with a start tangent along the positive x-axis. Values increases counter-clockwise, and decreases clockwise. Depending on the plane angle unit, either degree or radians, the sensible range is -360° ≤ n ≤ 360° (or -2π ≤ n ≤ 2π). Values larger then a full circle (>|360°| or >|2 π| shall not be used.X
3SegmentLengthIfcPositiveLengthMeasure The length along the curveX
IfcCircularArcSegment2D
4RadiusIfcPositiveLengthMeasure The radius of the circular arcX
5IsCCWIfcBoolean (counter-clockwise or clockwise) as the orientation of the circular arc with Boolean=”true” being counter-clockwise, or “to the left", and Boolean=”false” being clockwise, or “to the right”.X
Formal representations
XML Specification
 <xs:element name="IfcCircularArcSegment2D" type="ifc:IfcCircularArcSegment2D" substitutionGroup="ifc:IfcCurveSegment2D" nillable="true"/>
 <xs:complexType name="IfcCircularArcSegment2D">
  <xs:complexContent>
   <xs:extension base="ifc:IfcCurveSegment2D">
    <xs:attribute name="Radius" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="IsCCW" type="ifc:IfcBoolean" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcCircularArcSegment2D
 SUBTYPE OF (IfcCurveSegment2D);
  Radius : IfcPositiveLengthMeasure;
  IsCCW : IfcBoolean;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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