8.8.3.13 IfcDirectrixCurveSweptAreaSolid

ABSTRACT This definition may not be instantiated

8.8.3.13.1 Semantic 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 IfcDirectrixCurveSweptAreaSolid.

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.

8.8.3.13.2 Entity inheritance

8.8.3.13.3 Attributes

#	Attribute	Type	Description
IfcRepresentationItem (2)
	LayerAssignment	SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems	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.
	StyledByItem	SET [0:1] OF IfcStyledItem FOR Item	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.
IfcSolidModel (1)
*	Dim	IfcDimensionCount	This attribute is formally derived. `3` The space dimensionality of this class, it is always 3.
IfcSweptAreaSolid (2)
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.
2	Position	OPTIONAL 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.
Click to show 5 hidden inherited attributes Click to hide 5 inherited attributes
IfcDirectrixCurveSweptAreaSolid (3)
3	Directrix	IfcCurve	The curve used to define the sweeping operation. The solid is generated by sweeping the SELF\IfcSweptAreaSolid.SweptArea along the Directrix.
4	StartParam	OPTIONAL IfcCurveMeasureSelect	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.
5	EndParam	OPTIONAL IfcCurveMeasureSelect	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.

Table 8.8.3.13.A

8.8.3.13.4 Formal propositions

Name	Description
DirectrixBounded	If the values for StartParam or EndParam are omitted, then the Directrix has to be a bounded or closed curve.
`(EXISTS(StartParam) AND EXISTS(EndParam)) OR (SIZEOF(['IFC4X3_DEV_20bdb3d.IFCCONIC', 'IFC4X3_DEV_20bdb3d.IFCBOUNDEDCURVE'] * TYPEOF(Directrix)) = 1)`

Table 8.8.3.13.B

8.8.3.13.5 Formal representation

ENTITY IfcDirectrixCurveSweptAreaSolid
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcFixedReferenceSweptAreaSolid
	,IfcSurfaceCurveSweptAreaSolid))
 SUBTYPE OF (IfcSweptAreaSolid);
	Directrix : IfcCurve;
	StartParam : OPTIONAL IfcCurveMeasureSelect;
	EndParam : OPTIONAL IfcCurveMeasureSelect;
 WHERE
	DirectrixBounded : (EXISTS(StartParam) AND EXISTS(EndParam)) OR 
(SIZEOF(['IFC4X3_DEV_20bdb3d.IFCCONIC', 'IFC4X3_DEV_20bdb3d.IFCBOUNDEDCURVE'] * TYPEOF(Directrix)) = 1);
END_ENTITY;