8.9.3.41 IfcOffsetCurve3D

8.9.3.41.1 Semantic definition

An IfcOffsetCurve3D is a curve defined by an offset in 3D space from its BasisCurve.

Informal Propositions

At no point on the curve shall ref direction be parallel, or opposite to, the direction of the tangent vector.

8.9.3.41.2 Entity inheritance

8.9.3.41.3 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.
IfcCurve (1)
*	Dim	IfcDimensionCount	This attribute is formally derived. `IfcCurveDim(SELF)` The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.
IfcOffsetCurve (1)
1	BasisCurve	IfcCurve	The curve that is being offset.
Click to show 4 hidden inherited attributes
IfcOffsetCurve3D (3)
2	Distance	IfcLengthMeasure	The distance of the offset curve from the basis curve. The distance may be positive, negative or zero.
3	SelfIntersect	IfcLogical	An indication of whether the offset curve self-intersects, this is for information only.
4	RefDirection	IfcDirection	The direction used to define the direction of the offset curve 3d from the basis curve.

Table 8.9.3.41.B

8.9.3.41.4 Formal propositions

Name	Description
DimIs2D	The underlying curve shall be defined in three-dimensional space.
`BasisCurve.Dim = 3`

Table 8.9.3.41.C

8.9.3.41.5 Formal representation

 ENTITY IfcOffsetCurve3D
 SUBTYPE OF (IfcOffsetCurve);
	Distance : IfcLengthMeasure;
	SelfIntersect : IfcLogical;
	RefDirection : IfcDirection;
 WHERE
	DimIs2D : BasisCurve.Dim = 3;
END_ENTITY;

8.9.3.41 IfcOffsetCurve3D

8.9.3.41.1 Semantic definition

8.9.3.41.2 Entity inheritance

8.9.3.41.3 Attributes

8.9.3.41.4 Formal propositions

8.9.3.41.5 Formal representation

8.9.3.41.6 Changelog

8.9.3.41.6.1 IFC4

8.9.3.41.6.2 IFC4.1

	ENTITY IfcOffsetCurve3D
	SUBTYPE OF (IfcOffsetCurve);
	Distance : IfcLengthMeasure;
	SelfIntersect : IfcLogical;
	RefDirection : IfcDirection;
	WHERE
	DimIs2D : BasisCurve.Dim = 3;
	END_ENTITY;