Definition from IAI: The IfcBuildingElementProxy is a
proxy definition that provides the same functionality, as an
IfcBuildingElement, but without having a defined meaning of the special
type of building element, it represents.
NOTE The building element proxy should be used to
exchange special types of building elements, for which the current IFC Release
does not yet provide a semantic definition.
HISTORY: New entity in IFC Release
2.x.
Geometry Use Definitions
The geometric representation of any IfcBuildingElementProxy is
given by the IfcProductDefinitionShape and IfcLocalPlacement
allowing multiple geometric representations. The representation types defined
at the supertype IfcBuildingElement also apply.
Local Placement
The local placement for any IfcBuildingElementProxy is defined in
its supertype IfcProduct. It is defined by the IfcLocalPlacement,
which defines the local coordinate system that is referenced by all geometric
representations. The local placement can be given relativly.
Geometric Representation
Currently, the use of 'GeometricCurveSet', 'SurfaceModel', 'SweptSolid',
'Brep' representations is supported. In addition the general representation
types 'BoundingBox' and 'MappedRepresentation' are allowed.
GeometricSet Representation
Any building element proxy may be represented by a geometric set, given
by a collection of 2D points, curves and surfaces. It is ensured by assigning
the value 'GeometricSet' to the RepresentationType attribute of
IfcShapeRepresentation The RepresentationIdentifier of
IfcShapeRepresentation should then have the value 'FootPrint'.
SurfaceModel Representation
Any building element proxy may be represented by a surface model. The
surface model representation allows for the representation of complex element
shape without defining a volume. It is ensured by assigning the value
'SurfaceModel' to the RepresentationType attribute of
IfcShapeRepresentation The RepresentationIdentifier of
IfcShapeRepresentation should then have the value 'Body'.
Swept Solid Representation
Any building element proxy may be represented by a swept area solid
(either by extrusion or by revolution). The attribute RepresentationType
of IfcShapeRepresentation should have the value 'SweptSolid' and the
RepresentationIdentifier of IfcShapeRepresentation should then
have the value 'Body'. No further restrictions (e.g., for the profile or
extrusion direction) are defined at this level.
Brep Representation
The general b-rep geometric representation of
IfcBuildingElementProxy is defined using the Brep geometry. The Brep
representation allows for the representation of complex element shape. It is
ensured by assigning the value 'Brep' to the RepresentationType
attribute of IfcShapeRepresentation The RepresentationIdentifier
of IfcShapeRepresentation should then have the value 'Body'.
