IFC 4.3.x development

8.9.3.72 IfcSweptSurface

Change log

IFC4

additions where_rules SweptCurveType
deletions where_rules WR1
deletions where_rules WR2
modificationsattributes Position is_optionalChanged from False to True

8.9.3.72.1 Semantic definitions at the entity

An IfcSweptSurface is a surface defined by sweeping a curve. The swept surface is defined by a open or closed curve, represented by a subtype if IfcProfileDef, that is provided as a two-dimensional curve on an implicit plane, and by the sweeping operation.

  • The swept curve is defined by positioning the profile in the xy plane of the object coordinate system,
  • The sweeping operation is applied to the swept curve as defined within the subtypes of IfcSweptSurface;

The optional _Positio_n coordinate system allows for re-positioning the resulting swept surface relative to the object coordinate system.

NOTE  Definition according to ISO/CD 10303-42:1992
A swept surface is one that is constructed by sweeping a curve along another curve.

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

HISTORY  New entity in IFC2x.

IFC4 CHANGE  The attribute Position has been changed to OPTIONAL with upward compatibility for file-based exchange.

8.9.3.72.1 Attributes

# Attribute Type Description
IfcRepresentationItem
LayerAssignmentSET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItemsAssignment 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.
IfcGeometricRepresentationItem
IfcSurface
Dim INVALID The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item.

> IFC4 CHANGE Derived attribute promoted from subtypes.
IfcSweptSurface
1 SweptCurve IfcProfileDef The curve to be swept in defining the surface. The curve is defined as a profile within the position coordinate system.
2 Position OPTIONAL IfcAxis2Placement3D 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.

> IFC4 CHANGE  The attribute has been changed to OPTIONAL with upward compatibility for file-based exchange.

8.9.3.72.2 Entity inheritance

dot_inheritance IfcSurfaceOfLinearExtrusion IfcSurfaceOfLinearExtrusion IfcSweptSurface IfcSweptSurface IfcSurfaceOfLinearExtrusion->IfcSweptSurface IfcSurface IfcSurface IfcSweptSurface->IfcSurface IfcSurfaceOfRevolution IfcSurfaceOfRevolution IfcSurfaceOfRevolution->IfcSweptSurface IfcSurface_children 3 more... IfcSurface_children->IfcSurface IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcSurface->IfcGeometricRepresentationItem IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.9.3.72.3 Formal representations

ENTITY IfcSweptSurface
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcSurfaceOfLinearExtrusion
	,IfcSurfaceOfRevolution))
 SUBTYPE OF (IfcSurface);
	SweptCurve : IfcProfileDef;
	Position : OPTIONAL IfcAxis2Placement3D;
 WHERE
	SweptCurveType : SweptCurve.ProfileType = IfcProfileTypeEnum.Curve;
END_ENTITY;