IfcKnotType

Natural language names
enKnot Type
frType de nœud
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcKnotTypeADDED
Semantic definitions at the type
Type definition

The IfcKnotType indicates the particular form of b-spline knots.

NOTE  Definition according to ISO/CD 10303-42:1992
This type indicates that the B-spline knots shall have a particularly simple form enabling the knots themselves to be defaulted.
NOTE  Type adapted from knot_type defined in ISO 10303-42.
HISTORY  New type in IFC4.
Enumeration definition
ConstantDescription
UNIFORM_KNOTSThe form of knots appropriate for a uniform B-spline curve.
QUASI_UNIFORM_KNOTSThe form of knots appropriate for a quasi-uniform B-spline curve.
PIECEWISE_BEZIER_KNOTSThe form of knots appropriate for a piecewise B�?©zier curve.
UNSPECIFIEDThe type of knots is not specified. This includes the case of non uniform knots.
Formal representations
XSD Specification
 <xs:simpleType name="IfcKnotType">
  <xs:restriction base="xs:string">
   <xs:enumeration value="uniform_knots"/>
   <xs:enumeration value="quasi_uniform_knots"/>
   <xs:enumeration value="piecewise_bezier_knots"/>
   <xs:enumeration value="unspecified"/>
  </xs:restriction>
 </xs:simpleType>
EXPRESS Specification
TYPE IfcKnotType = ENUMERATION OF (
 UNIFORM_KNOTS,
 QUASI_UNIFORM_KNOTS,
 PIECEWISE_BEZIER_KNOTS,
 UNSPECIFIED);
END_TYPE;

Link to EXPRESS-G diagram EXPRESS-G diagram

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