Kurve im Parameterraum einer Fläche | |
Pcurve | |
Courbe basée sur une surface |
Item | SPF | XML | Change | Description | IFC2x3 to IFC4 |
---|---|---|---|---|
IfcPcurve | ADDED |
The IfcPcurve is a curve defined within the parameter space of its reference surface.
NOTE Definition according to ISO/CD 10303-42:1992
A pcurve is a curve which lies on the basis of a surface and is defined in the parameter space of that surface. The basis curve is a curve defined in the two-dimensional parametric space of a reference basis surface. Although it is defined by a curve in two dimensional space, the variables involved are u and v, which occur in the parametric representation of the referenced surface, rather than the x, y, Cartesian coordinates. The basis curve is only defined within the parametric range of the surface.
NOTE Entity adapted from pcurve in ISO 10303-42.
HISTORY New entity in IFC4.
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
1 | BasisSurface | IfcSurface | [1:1] | X | |
2 | ReferenceCurve | IfcCurve | [1:1] | X |
Rule | Description |
---|---|
DimIs2D | The dimensionality of the parameter space curve shall be 2. |
# | 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 | |
IfcPcurve | |||||
1 | BasisSurface | IfcSurface | [1:1] | X | |
2 | ReferenceCurve | IfcCurve | [1:1] | X |
<xs:element name="IfcPcurve" type="ifc:IfcPcurve" substitutionGroup="ifc:IfcCurve" nillable="true"/>
<xs:complexType name="IfcPcurve">
<xs:complexContent>
<xs:extension base="ifc:IfcCurve">
<xs:sequence>
<xs:element name="BasisSurface" type="ifc:IfcSurface" nillable="true"/>
<xs:element name="ReferenceCurve" type="ifc:IfcCurve" nillable="true"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcPcurve
SUBTYPE OF (IfcCurve);
BasisSurface : IfcSurface;
ReferenceCurve : IfcCurve;
WHERE
DimIs2D : ReferenceCurve.Dim = 2;
END_ENTITY;