8.9.3.67 IfcSurface

RV ⓘ

AbV ⓘ

ABSTRACT This definition may not be instantiated

8.9.3.67.1 Semantic definition

An IfcSurface is a 2-dimensional representation item positioned in 3-dimensional space. 2-dimensional means that each point at the surface can be defined by a 2-dimensional coordinate system, usually by u and v coordinates.

Informal Propositions

A surface has non zero area.
A surface is arcwise connected.

8.9.3.67.2 Entity inheritance

8.9.3.67.3 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.
Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes
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.

Table 8.9.3.67.A

8.9.3.67.4 Formal representation

ENTITY IfcSurface
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcBoundedSurface
	,IfcElementarySurface
	,IfcSectionedSurface
	,IfcSweptSurface))
 SUBTYPE OF (IfcGeometricRepresentationItem);
 DERIVE
	 Dim : IfcDimensionCount := 3;
END_ENTITY;