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8.9.3.69 IfcSurfaceOfLinearExtrusion

8.9.3.69.1 Semantic definition

The IfcSurfaceOfLinearExtrusion is a surface derived by sweeping a curve along a vector.

V = ExtrusionAxis

Image The parameterization range for v is -∞ < v < ∞ and for u it is defined by the curve parameterization.
Figure 8.9.3.69.A

Informal Propositions

  1. The surface shall not self-intersect

8.9.3.69.2 Entity inheritance

8.9.3.69.3 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.
IfcSurface (1)
* Dim IfcDimensionCount

This attribute is formally derived. 

3

The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item.
IfcSweptSurface (2)
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.
Click to show 5 hidden inherited attributes Click to hide 5 inherited attributes
IfcSurfaceOfLinearExtrusion (3)
3 ExtrudedDirection IfcDirection

The direction of the extrusion.
4 Depth IfcLengthMeasure

The depth of the extrusion, it determines the parameterization.
* ExtrusionAxis IfcVector

This attribute is formally derived. 

IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcVector (ExtrudedDirection, Depth)

The extrusion axis defined as vector.
Table 8.9.3.69.B

8.9.3.69.4 Formal propositions

Name Description
DepthGreaterZero

No description available. 

Depth > 0.
Table 8.9.3.69.C

8.9.3.69.5 Formal representation 

ENTITY IfcSurfaceOfLinearExtrusion
 SUBTYPE OF (IfcSweptSurface);
	ExtrudedDirection : IfcDirection;
	Depth : IfcLengthMeasure;
 DERIVE
	 ExtrusionAxis : IfcVector := IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcVector (ExtrudedDirection, Depth);
 WHERE
	DepthGreaterZero : Depth > 0.;
END_ENTITY;

8.9.3.69.6 References

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8.9.3.69.7 Changelog

8.9.3.69.7.1 IFC4

  • where rule, DepthGreaterZero
  • where rule, WR41