IfcBuildingElementProxy
Definition from buildingSMART: 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.
NOTE1 The IfcBuildingElementProxy should be used to exchange special types of building elements for which the current IFC Release does not yet provide a semantic definition.
NOTE2 The IfcBuildingElementProxy can also be used to represent building elements for which the participating applications can not provide additional semantic classification.
HISTORY New entity in IFC Release 2x.
Type Use Definition
The IfcBuildingElementProxy defines the occurrence of any building element, common information about the types (or styles) is handled by IfcBuildingElementProxyType.
The IfcBuildingElementProxyType (if present) may establish the common type name, usage (or predefined) type, common material, common set of properties and common shape representations (using IfcRepresentationMap). The IfcBuildingElementProxyType is attached using the IfcRelDefinedByType.RelatingType objectified relationship and is accessible by the inverse IsDefinedBy attribute.
NOTE The IfcBuildingElementProxyType can be used to share common information among many occurrences of the same proxy without establishing a particular semantic meaning of the type.
If no IfcBuildingElementProxyType is attached (i.e. if only occurrence information is given) the predefined type may be given by using the ObjectType attribute.
Property Set Use Definition:
The property sets relating to the IfcBuildingElementProxy are defined by the IfcPropertySet and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following property set definitions specific to the IfcBuildingElementProxy/i> are part of this IFC release:
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 relatively.
Geometric Representation
Currently, the use of the representation types 'BoundingBox', 'GeometricSet', 'GeometricCurveSet', 'SweptSolid', 'SurfaceModel', 'Brep', and 'MappedRepresentation' are allowed. The geometry use definitions for 'BoundingBox', 'SurfaceModel', 'Brep', and 'MappedRepresentation' are explained at the supertype IfcBuildingElement.
GeometricCurveSet Representation
Any building element proxy may be represented by a geometric curve set, given by a collection of 2D points and curves. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
GeometricSet Representation
Any building element proxy may be represented by a geometric set, given by a collection of 2D and 3D points, curves, and surfaces. It represents the body of the proxy object, when no topological structure is available. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
Swept Solid Representation
Any building element proxy may be represented by swept solid geometry (either by extrusion or by revolution). The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
No further restrictions (e.g., for the profile or extrusion direction) are defined at this level. A single or multiple swept area solid(s) can be the Items of the IfcShapeRepresentation.
EXPRESS specification:
|
CompositionType | : | Indication, whether the proxy is intended to form an aggregation (COMPLEX), an integral element (ELEMENT), or a part in an aggregation (PARTIAL). |
WR1 | : | A Name attribute should be asserted for a building element proxy. |
|