|modifications||attributes PlacementRelTo name||Changed from PlacementRelTo to PlacementMeasuredAlong|
|modifications||attributes PlacementMeasuredAlong definition||Changed from IfcCurve to IfcAxis2PlacementLinear|
|modifications||attributes PlacementMeasuredAlong name||Changed from PlacementMeasuredAlong to RelativePlacement|
IfcLinearPlacement provides a specialization of IfcObjectPlacement in which the placement and axis direction of the object coordinate system is defined by a reference to a curve. RelativePlacement is therefore restricted to IfcAxis2PlacementLinear.
|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 IfcLinearPlacement SUBTYPE OF (IfcObjectPlacement); RelativePlacement : IfcAxis2PlacementLinear; CartesianPosition : OPTIONAL IfcAxis2Placement3D; END_ENTITY;