ifc-syntax-geometry-placement
IFC Syntax : Geometry Placement
IFC stores an element's shape and its position separately. The geometry items
inside a representation are defined in a local coordinate system whose origin is
(0,0,0). Where that local system sits in the world is carried by
IfcProduct.ObjectPlacement, an IfcObjectPlacement.
This skill covers the placement tree : how placements chain parent to child, how an
axis placement defines a coordinate system, and how a consumer resolves a product to
world coordinates. Georeferencing (IfcMapConversion, IfcProjectedCRS, the
IfcSite reference latitude/longitude) is a separate concern : see
ifc-syntax-georeferencing.
Applies to IFC2x3, IFC4, and IFC4.3. One attribute moved between versions and IFC4.3 added a third placement subtype : see the Version Differences section.