IfcDirectrixCurveSweptAreaSolid

Item	SPF	XML	Change	Description
IFC4x2 to IFC4x3_RC1
IfcDirectrixCurveSweptAreaSolid			ADDED

Semantic definitions at the entity

Entity definition

An abstract entity defining common information about a type of swept area solid which is the result of sweeping an area along a Directrix. The swept area is provided by a subtype of IfcProfileDef. The profile is placed by an implicit cartesian transformation operator at the start point of the sweep, where the profile normal agrees to the tangent of the directrix at this point. The direction of profile�s x-axis is specialized by the subtypes of IfcDirextrixCurveSweptAreaSolid. The start of the sweeping operation is at the StartParam, the parameter value is provided based on the curve parameterization. If no StartParam is provided the start defaults to the begin of the directrix. The end of the sweeping operation is at the EndParam, the parameter value is provided based on the curve parameterization. If no EndParam is provided the end defaults to the end of the directrix.

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
3	Directrix	IfcCurve		The curve used to define the sweeping operation. The solid is generated by sweeping the SELF\IfcSweptAreaSolid.SweptArea along the Directrix.	X
4	StartParam	IfcParameterValue	?	The parameter value on the Directrix at which the sweeping operation commences. If no value is provided the start of the sweeping operation is at the start of the Directrix.	X
5	EndParam	IfcParameterValue	?	The parameter value on the Directrix at which the sweeping operation ends. If no value is provided the end of the sweeping operation is at the end of the Directrix.	X

Formal Propositions

Rule	Description
DirectrixBounded	If the values for StartParam or EndParam are omited, then the Directrix has to be a bounded or closed curve.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
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. IFC2x3 CHANGE The inverse attribute LayerAssignments has been added. IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.	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. IFC2x3 CHANGE The inverse attribute StyledByItem has been added.	X
IfcGeometricRepresentationItem
IfcSolidModel
	Dim :=3	IfcDimensionCount		The space dimensionality of this class, it is always 3.	X
IfcSweptAreaSolid
1	SweptArea	IfcProfileDef		The surface defining the area to be swept. It is given as a profile definition within the xy plane of the position coordinate system.	X
2	Position	IfcAxis2Placement3D	?	Position coordinate system for the resulting swept solid of the sweeping operation. The position coordinate system allows for re-positioning of the swept solid. If not provided, the swept solid remains within the position as determined by the cross section or by the directrix used for the sweeping operation. IFC4 CHANGE The attribute has been changed to OPTIONAL with upward compatibility for file-based exchange.	X
IfcDirectrixCurveSweptAreaSolid
3	Directrix	IfcCurve		The curve used to define the sweeping operation. The solid is generated by sweeping the SELF\IfcSweptAreaSolid.SweptArea along the Directrix.	X
4	StartParam	IfcParameterValue	?	The parameter value on the Directrix at which the sweeping operation commences. If no value is provided the start of the sweeping operation is at the start of the Directrix.	X
5	EndParam	IfcParameterValue	?	The parameter value on the Directrix at which the sweeping operation ends. If no value is provided the end of the sweeping operation is at the end of the Directrix.	X

Formal representations

XML Specification

 <xs:element name="IfcDirectrixCurveSweptAreaSolid" type="ifc:IfcDirectrixCurveSweptAreaSolid" abstract="true" substitutionGroup="ifc:IfcSweptAreaSolid" nillable="true"/>

 <xs:complexType name="IfcDirectrixCurveSweptAreaSolid" abstract="true">

  <xs:complexContent>

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

    <xs:sequence>

     <xs:element name="Directrix" type="ifc:IfcCurve" nillable="true"/>

    </xs:sequence>

    <xs:attribute name="StartParam" type="ifc:IfcParameterValue" use="optional"/>

    <xs:attribute name="EndParam" type="ifc:IfcParameterValue" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcDirectrixCurveSweptAreaSolid

 ABSTRACT SUPERTYPE OF(ONEOF(IfcFixedReferenceSweptAreaSolid, IfcSurfaceCurveSweptAreaSolid))

 SUBTYPE OF (IfcSweptAreaSolid);

  Directrix : IfcCurve;

  StartParam : OPTIONAL IfcParameterValue;

  EndParam : OPTIONAL IfcParameterValue;

 WHERE

  DirectrixBounded : (EXISTS(StartParam) AND EXISTS(EndParam)) OR 

(SIZEOF(['IFCGEOMETRYRESOURCE.IfcConic', 'IFCGEOMETRYRESOURCE.IfcBoundedCurve'] * TYPEOF(Directrix)) = 1);
END_ENTITY;

 EXPRESS-G diagram