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IfcSurface

Definition from ISO/CD 10303-42:1992: A surface (IfcSurface) 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, only two subtypes have been incorporated into IFC Release 1.5 - elementary_surface (as IfcElementarySurface) and a limited adaptation of bounded_surface (as IfcCurveBoundedPlane). 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
ISSUE: See issue I-226 for changes made in IFC Release 1.5.

Informal proposition:

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

EXPRESS specification:

ENTITY IfcSurface
ABSTRACT SUPERTYPE OF (ONEOF(IfcElementarySurface, IfcSweptSurface, IfcBoundedSurface))
SUBTYPE OF ( IfcGeometricRepresentationItem);
END_ENTITY;

References (5):

Name Type Referred through Express-G
IfcBoundedSurface Entity
Supertype
Diagram 7
IfcElementarySurface Entity
Supertype
Diagram 7
IfcGeometricRepresentationItem Entity
Subtype
Diagram 1
IfcRectangularTrimmedSurface Entity
Attribute 'BasisSurface'
Diagram 7
IfcSweptSurface Entity
Supertype
Diagram 8

Inheritance graph

ENTITY IfcSurface;
ENTITY IfcRepresentationItem;
ENTITY IfcGeometricRepresentationItem;
ENTITY IfcSurface;
END_ENTITY;