|modifications||inverses PlacesObject definition||Changed from SET OF [1:1] IfcProduct FOR ObjectPlacement to SET OF [0:?] IfcProduct FOR ObjectPlacement|
The object placement can be given:
In any case the object placement has to unambiguously define the object coordinate system as either two-dimensional axis placement (IfcAxis2Placement2D) or three-dimensional axis placement (IfcAxis2Placement3D). The axis placement may have to be calculated.
HISTORY New entity in IFC2x.
|PlacesObject||SET [0:?] OF IfcProduct FOR ObjectPlacement||The IfcObjectPlacement shall be used to provide a placement and |
an object coordinate system for instances of IfcProduct.
> If an IfcObjectPlacement is shared by many instances of IfcProduct it does not apply a semantic meaning of being a shared placement that needs to be maintained. The same instance of IfcObjectPlacement could simply be used to reduce exchange file size.
> IFC2x3 CHANGE New inverse attribute.
> IFC4 CHANGE The cardinality has changed to 0..n to allow reuse of instances of IfcObjectPlacement as placement object in one to many products. It takes also into account that it can act as a placement for IfcStructuralAnalysisModel.
|1||PlacementRelTo||OPTIONAL IfcObjectPlacement||Reference to object placement that provides the relative placement with its placement in a grid, local coordinate system or linear referenced placement. If it is omitted, then in the case of linear placement it is established by the origin of horizontal alignment of the referenced IfcAlignment Axis. In the case of local placement it is established by the geometric representation context.|
ENTITY IfcObjectPlacement ABSTRACT SUPERTYPE OF (ONEOF (IfcGridPlacement ,IfcLinearPlacement ,IfcLocalPlacement)); PlacementRelTo : OPTIONAL IfcObjectPlacement; INVERSE PlacesObject : SET [0:?] OF IfcProduct FOR ObjectPlacement; END_ENTITY;