IFC 4.3.x development

8.9.3.32 IfcElementarySurface

8.9.3.32.1 Semantic definitions at the entity

An IfcElementarySurface in the common supertype of analytical surfaces.

NOTE  Definition according to ISO/CD 10303-42:1992
An elementary surface (IfcElementarySurface) is a simple analytic surface with defined parametric representation.

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

HISTORY  New entity in IFC1.5

8.9.3.32.1 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.
IfcElementarySurface
1 Position IfcAxis2Placement3D The position and orientation of the surface. This attribute is used in the definition of the parameterization of the surface.

8.9.3.32.2 Entity inheritance

dot_inheritance IfcElementarySurface_children 3 more... IfcElementarySurface IfcElementarySurface IfcElementarySurface_children->IfcElementarySurface IfcSurface IfcSurface IfcElementarySurface->IfcSurface 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

8.9.3.32.3 Formal representations

ENTITY IfcElementarySurface
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcCylindricalSurface
	,IfcPlane
	,IfcSphericalSurface
	,IfcToroidalSurface))
 SUBTYPE OF (IfcSurface);
	Position : IfcAxis2Placement3D;
END_ENTITY;