IfcPlacement

Semantic definitions at the entity

Entity definition

An IfcPlacement is an abstract supertype of placement subtypes that define the location of an item, or an entire shape representation, and provide its orientation. All placement subtypes define right-handed Cartesian coordinate systems and do not allow mirroring.

NOTE Cartesian transformations including mirroring and scaling are supported by IfcCartesianTransformationOperator

NOTE Definition according to ISO/CD 10303-42:1992
A placement locates a geometric item with respect to the coordinate system of its geometric context. It locates the item to be defined and, in the case of the axis placement subtypes, gives its orientation.

NOTE Entity adapted from placement defined in ISO 10303-42.

HISTORY New entity in IFC1.0

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
1	Location	IfcCartesianPoint	[1:1]	The geometric position of a reference point, such as the center of a circle, of the item to be located.	X
	Dim :=Location.Dim	IfcDimensionCount	[1:1]	The space dimensionality of this class, derived from the dimensionality of the location.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @AssignedItems	S[0:1]	Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.	X
	StyledByItem	IfcStyledItem @Item	S[0:1]	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.	X
IfcGeometricRepresentationItem
IfcPlacement
1	Location	IfcCartesianPoint	[1:1]	The geometric position of a reference point, such as the center of a circle, of the item to be located.	X
	Dim :=Location.Dim	IfcDimensionCount	[1:1]	The space dimensionality of this class, derived from the dimensionality of the location.	X

Formal representations

XSD Specification

 <xs:element name="IfcPlacement" type="ifc:IfcPlacement" abstract="true" substitutionGroup="ifc:IfcGeometricRepresentationItem" nillable="true"/>

 <xs:complexType name="IfcPlacement" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:IfcGeometricRepresentationItem">

    <xs:sequence>

     <xs:element name="Location" type="ifc:IfcCartesianPoint" nillable="true"/>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcPlacement

 ABSTRACT SUPERTYPE OF(ONEOF(IfcAxis1Placement, IfcAxis2Placement2D, IfcAxis2Placement3D))

 SUBTYPE OF (IfcGeometricRepresentationItem);

  Location : IfcCartesianPoint;

 DERIVE

  Dim : IfcDimensionCount := Location.Dim;

END_ENTITY;

 EXPRESS-G diagram

	Positionierung
	Placement
	Positionnement