8.8.3.14 IfcDirectrixDerivedReferenceSweptAreaSolid
8.8.3.14.1 Semantic definition
In most cases the case the IfcDirectrixDerivedReferenceSweptAreaSolid has exactly the same behavior as IfcFixedReferenceSweptAreaSolid, except when the Directrix not only defines a tangent direction but a tangent plane for each point on the curve. Like for example in the case of a IfcSegmentReferenceCurve, the change in y direction of the tangent plane is added to the fixed reference. The change in y direction at the start of the directrix is defined to be 0 independent from StartParam value, this means the change can be non-zero at the start of the resulting Swept Area Solid.
8.8.3.14.2 Entity inheritance
- 
- IfcSolidModel
 - IfcAnnotationFillArea
 - IfcBooleanResult
 - IfcBoundingBox
 - IfcCartesianPointList
 - IfcCartesianTransformationOperator
 - IfcCsgPrimitive3D
 - IfcCurve
 - IfcDirection
 - IfcFaceBasedSurfaceModel
 - IfcFillAreaStyleHatching
 - IfcFillAreaStyleTiles
 - IfcGeometricSet
 - IfcHalfSpaceSolid
 - IfcLightSource
 - IfcPlacement
 - IfcPlanarExtent
 - IfcPoint
 - IfcSectionedSpine
 - IfcSegment
 - IfcShellBasedSurfaceModel
 - IfcSurface
 - IfcTessellatedItem
 - IfcTextLiteral
 - IfcVector
 
 
8.8.3.14.3 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.  | 
|
| 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.  | 
|
| IfcSolidModel (1) | |||
| * | Dim | IfcDimensionCount | 
 This attribute is formally derived. 
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.  | 
| 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.  | 
| Click to show 8 hidden inherited attributes Click to hide 8 inherited attributes | |||
| IfcFixedReferenceSweptAreaSolid (1) | |||
| 6 | FixedReference | IfcDirection | 
 No description available.  | 
8.8.3.14.4 Formal representation
ENTITY IfcDirectrixDerivedReferenceSweptAreaSolid
 SUBTYPE OF (IfcFixedReferenceSweptAreaSolid);
END_ENTITY;