IfcSurfaceOfRevolution

Semantic definitions at the entity

Entity definition

The IfcSurfaceOfRevolution is a surface derived by rotating a curve about an axis.

NOTE Definition according to ISO/CD 10303-42:1992
A surface of revolution is the surface obtained by rotating a curve one complete revolution about an axis. The data shall be interpreted as below.

The parameterization is as follows where the curve has a parameterization λ(u):

C = AxisPosition.Location
V = AxisPosition.Z

In order to produce a single-value surface the a complete revolution, the curve shall be such that when expressed in a cylindrical coordinate system the curve shall be such that when expressed in a cylindrical coordinate system (r,φ ,z) centred at C with an axis V no two distinct parametric points on the curve shall have the same values for (r, z). For a surface of revolution the parametric range is 0 < u < 360 degree. The parameterization range for v is defined by referenced curve.

NOTE Entity adapted from surface_of_revolution defined in ISO 10303-42.

HISTORY New entity in IFC2x.

Informal Propositions:

The surface shall not self-intersect
The swept curve shall not be coincident with the axis line for any finite part of its legth.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
3	AxisPosition	IfcAxis1Placement	[1:1]	A point on the axis of revolution and the direction of the axis of revolution.	X
	AxisLine :=IfcRepresentationItem() \|\| IfcGeometricRepresentationItem () \|\| IfcCurve() \|\| IfcLine(AxisPosition.Location, IfcRepresentationItem() \|\| IfcGeometricRepresentationItem () \|\| IfcVector(AxisPosition.Z,1.0))	IfcLine	[1:1]	The line coinciding with the axis of revolution.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	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
IfcSurface
	Dim :=3	IfcDimensionCount	[1:1]	The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item.	X
IfcSweptSurface
1	SweptCurve	IfcProfileDef	[1:1]	The curve to be swept in defining the surface. The curve is defined as a profile within the position coordinate system.	X
2	Position	IfcAxis2Placement3D	[0:1]	Position coordinate system for the swept surface, provided by a profile definition within the XY plane of the Position coordinates. If not provided, the position of the profile being swept is determined by the object coordinate system. In this case, the swept surface is not repositioned.	X
IfcSurfaceOfRevolution
3	AxisPosition	IfcAxis1Placement	[1:1]	A point on the axis of revolution and the direction of the axis of revolution.	X
	AxisLine :=IfcRepresentationItem() \|\| IfcGeometricRepresentationItem () \|\| IfcCurve() \|\| IfcLine(AxisPosition.Location, IfcRepresentationItem() \|\| IfcGeometricRepresentationItem () \|\| IfcVector(AxisPosition.Z,1.0))	IfcLine	[1:1]	The line coinciding with the axis of revolution.	X

Formal representations

XSD Specification

 <xs:element name="IfcSurfaceOfRevolution" type="ifc:IfcSurfaceOfRevolution" substitutionGroup="ifc:IfcSweptSurface" nillable="true"/>

 <xs:complexType name="IfcSurfaceOfRevolution">

  <xs:complexContent>

   <xs:extension base="ifc:IfcSweptSurface">

    <xs:sequence>

     <xs:element name="AxisPosition" type="ifc:IfcAxis1Placement" nillable="true"/>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcSurfaceOfRevolution

 SUBTYPE OF (IfcSweptSurface);

  AxisPosition : IfcAxis1Placement;

 DERIVE

  AxisLine : IfcLine := IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcCurve() || IfcLine(AxisPosition.Location, 
  IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcVector(AxisPosition.Z,1.0));

END_ENTITY;

 EXPRESS-G diagram

Item	Change	Description
IFC2x3 to IFC4
IfcSurfaceOfRevolution
Position	MODIFIED	Instantiation changed to OPTIONAL.

	Oberfläche - Entlang einer Achse rotiert
	Surface Of Revolution
	Surface de révolution