Kreis | |

Circle | |

Cercle |

An IfcCircle is a curve consisting of a set of points having equal distance from the center.

NOTE A circular arc segment is defined by using theIfcTrimmedCurvewithBasisCurvebeing an IfcCircle or alternatively as a circular arc defined by three points within an IfcIndexedPolyCurve.

Figure 173 illustrates the definition of IfcCircle within a three-dimensional position coordinate system placed within the object coordinate system of an element.

Figure 173 — Circle layout |

The IfcCircle ia parameterized using numeric values in correspondence to the plane angle unit provided within the IfcUnitAssignment. If the plane angle unit is 'Degree' the parametric range of a circle is 0 ≤ *u* ≤ 360, if the plane angle unit is radians, the parametric range is 0 ≤ *u* ≤ 2π.

NOTE Definition according to ISO/CD 10303-42:1992

A circle is defined by a radius and the location and orientation of the circle. Interpretation of data should be as follows:`C = SELF\IfcConic.Position.Location`

x = SELF\IfcConic.Position.P[1]

y = SELF\IfcConic.Position.P[2]

z = SELF\IfcConic.Position.P[3]

R = Radiusand the circle is parameterized as

The parameterization range is 0 ≤

u≤ 360 degree,uis an angular parameter and when a numerical value is specified it shall use the current units for plane angle measure. In the placement coordinate system defined above, the circle is the equationC= 0, whereThe positive sense of the circle at any point is in the tangent direction,

T, to the curve at the point, where

NOTE Entity adapted fromcircledefined in ISO 10303-42

HISTORY New entity in IFC1.0

# | Attribute | Type | Cardinality | Description | R |
---|---|---|---|---|---|

2 | Radius | IfcPositiveLengthMeasure | The radius of the circle, which shall be greater than zero. | X |

# | Attribute | Type | Cardinality | Description | R |
---|---|---|---|---|---|

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.
IFC2x3 CHANGE The inverse attribute IFC4 CHANGE The inverse attribute | ||

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.
IFC2x3 CHANGE The inverse attribute | X | |

IfcGeometricRepresentationItem | |||||

IfcCurve | |||||

Dim :=IfcCurveDim(SELF) | IfcDimensionCount | The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve. | X | ||

IfcConic | |||||

1 | Position | IfcAxis2Placement | The location and orientation of the conic. Further details of the interpretation of this attribute are given for the individual subtypes." | X | |

IfcCircle | |||||

2 | Radius | IfcPositiveLengthMeasure | The radius of the circle, which shall be greater than zero. | X |

` <xs:element name="IfcCircle" type="ifc:IfcCircle" substitutionGroup="ifc:IfcConic" nillable="true"/>`

<xs:complexType name="IfcCircle">

<xs:complexContent>

<xs:extension base="ifc:IfcConic">

<xs:attribute name="Radius" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

</xs:extension>

</xs:complexContent>

</xs:complexType>

```
ENTITY IfcCircle
```

SUBTYPE OF (IfcConic)**;**

Radius : IfcPositiveLengthMeasure;

END_ENTITY;