Bézier-Spline-Flächen (verschiedene Formen) | |

BSpline Surface Form | |

Forme de surface Bspline |

Item | SPF | XML | Change | Description |
---|---|---|---|---|

IFC2x3 to IFC4 |
||||

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 fromb_spline_surface_formdefined 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