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	B
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	B
IfcRepresentationItem
	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	-		This attribute is out of scope for this model view definition and shall not be set.
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