8.9.3.69 IfcSurfaceOfLinearExtrusion

Definition according to ISO/CD 10303-42:1992 This surface is a simple swept surface or a generalized cylinder obtained by sweeping a curve in a given direction. The parameterization is as follows where the curve has a parameterization λ(u): Entity adapted from surface_of_linear_extrusion defined in ISO 10303-42. New entity in IFC2x.

V = ExtrusionAxis

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

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. 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.
IfcSurface (1)
*	Dim	IfcDimensionCount	This attribute is formally derived. `3` The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item. IFC4-CHANGE Derived attribute promoted from subtypes.
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. 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
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

IfcSweptSurface

8.9.3.69 IfcSurfaceOfLinearExtrusion

8.9.3.69.1 Semantic definition

8.9.3.69.2 Entity inheritance

8.9.3.69.3 Attributes

8.9.3.69.4 Formal propositions

8.9.3.69.5 Formal representation

8.9.3.69.6 References

8.9.3.69.7 Changelog

8.9.3.69.7.1 IFC4