IfcSurface

Semantic definitions at the entity

Entity definition

Definition from ISO/CD 10303-42:1992: A surface can be envisioned as a set of connected points in 3-dimensional space which is always locally 2-dimensional, but need not be a manifold.

NOTE Corresponding STEP entity: surface, the following subtypes have been incorporated into IFC - elementary_surface (as IfcElementarySurface), swept_surface (as IfcSweptSurface) and bounded_surface (as IfcBoundedSurface). Please refer to ISO/IS 10303-42:1994, p. 68 for the final definition of the formal standard.

HISTORY New class in IFC Release 1.5

Informal proposition:

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

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	A
IfcRepresentationItem
IfcGeometricRepresentationItem
IfcSurface

Formal representations

XSD Specification

 <xs:element name="IfcSurface" type="ifc:IfcSurface" abstract="true" substitutionGroup="ifc:IfcGeometricRepresentationItem" nillable="true"/>

 <xs:complexType name="IfcSurface" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:IfcGeometricRepresentationItem"/>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcSurface

 SUBTYPE OF (IfcGeometricRepresentationItem);

END_ENTITY;

 EXPRESS-G diagram