 | Bézier-Spline-Flächen (verschiedene Formen) |
 | BSpline Surface Form |
 | Forme de surface Bspline |
| Item | SPF | XML | Change | Description | IFC2x3 to IFC4 4.0.0.0 |
|---|---|---|---|---|
| IfcBSplineSurfaceForm | ADDED | IFC2x3 to IFC4 4.0.0.0 | ||
| IfcBSplineSurfaceForm | ADDED |
The IfcBSplineSurfaceForm represents a part of a surface of some specific form.
NOTE Definition according to ISO/CD 10303-42:1992
This type is used to indicate that the B-spline surface represents a part of a surface of some specific form.
NOTE Type adapted from b_spline_surface_form defined in ISO 10303-42.
HISTORY New type in IFC4.
| Constant | Description |
|---|---|
| PLANE_SURF | A bounded portion of a plane represented by a B-spline surface of degree 1 in each parameter. |
| CYLINDRICAL_SURF | A bounded portion of a cylindrical surface. |
| CONICAL_SURF | A bounded portion of the surface of a right circular cone. |
| SPHERICAL_SURF | A bounded portion of a sphere, or a complete sphere, represented by a B-spline surface. |
| TOROIDAL_SURF | A torus, or portion of a torus, represented by a B-spline surface. |
| SURF_OF_REVOLUTION | A bounded portion of a surface of revolution. |
| RULED_SURF | A surface constructed from two parametric curves by joining with straight lines corresponding points with the same parameter value on each of the curves. |
| GENERALISED_CONE | A special case of a ruled surface in which the second curve degenerates to a single point; when represented by a B-spline surface all the control points along one edge will be coincident. |
| QUADRIC_SURF | A bounded portion of one of the class of surfaces of degree 2 in the variables x, y and z. |
| SURF_OF_LINEAR_EXTRUSION | A bounded portion of a surface of linear extrusion represented by a B-spline surface of degree 1 in one of the parameters. |
| UNSPECIFIED | A surface for which no particular form is specified. |
<xs:simpleType name="IfcBSplineSurfaceForm">
<xs:restriction base="xs:string">
<xs:enumeration value="plane_surf"/>
<xs:enumeration value="cylindrical_surf"/>
<xs:enumeration value="conical_surf"/>
<xs:enumeration value="spherical_surf"/>
<xs:enumeration value="toroidal_surf"/>
<xs:enumeration value="surf_of_revolution"/>
<xs:enumeration value="ruled_surf"/>
<xs:enumeration value="generalised_cone"/>
<xs:enumeration value="quadric_surf"/>
<xs:enumeration value="surf_of_linear_extrusion"/>
<xs:enumeration value="unspecified"/>
</xs:restriction>
</xs:simpleType>
TYPE IfcBSplineSurfaceForm = ENUMERATION OF (
PLANE_SURF,
CYLINDRICAL_SURF,
CONICAL_SURF,
SPHERICAL_SURF,
TOROIDAL_SURF,
SURF_OF_REVOLUTION,
RULED_SURF,
GENERALISED_CONE,
QUADRIC_SURF,
SURF_OF_LINEAR_EXTRUSION,
UNSPECIFIED);
END_TYPE;
References: IfcBSplineSurface
EXPRESS-G diagram
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