 | Knot Type |
 | Type de nœud |
| Item | SPF | XML | Change | Description | IFC2x3 to IFC4 4.0.0.0 |
|---|---|---|---|---|
| IfcKnotType | ADDED |
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.
| Constant | Description |
|---|---|
| UNIFORM_KNOTS | The form of knots appropriate for a uniform B-spline curve. |
| QUASI_UNIFORM_KNOTS | The form of knots appropriate for a quasi-uniform B-spline curve. |
| PIECEWISE_BEZIER_KNOTS | The form of knots appropriate for a piecewise Bezier curve. |
| UNSPECIFIED | The type of knots is not specified. This includes the case of non uniform knots. |
<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>
TYPE IfcKnotType = ENUMERATION OF (
UNIFORM_KNOTS,
QUASI_UNIFORM_KNOTS,
PIECEWISE_BEZIER_KNOTS,
UNSPECIFIED);
END_TYPE;
References: IfcBSplineCurveWithKnots
IfcBSplineSurfaceWithKnots
EXPRESS-G diagram
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