IfcLinearPlacement

Natural language names
Linear Placement
Change log
ItemSPFXMLChangeDescription
IFC4x1 Final 4.1.0.0
    IfcLinearPlacementADDED
IFC4x2 Candidate 4.2.0.0
    IfcLinearPlacement
      PlacementRelToXXMODIFIEDType changed from IfcCurve to IfcObjectPlacement.
Instantiation changed to OPTIONAL.
      PlacementMeasuredAlongXXMODIFIEDName changed from Distance to PlacementMeasuredAlong.
Type changed from IfcDistanceExpression to IfcCurve.
      DistanceXXMODIFIEDName changed from Orientation to Distance.
Type changed from IfcOrientationExpression to IfcDistanceExpression.
Instantiation changed from OPTIONAL.
      OrientationXXMODIFIEDName changed from CartesianPosition to Orientation.
Type changed from IfcAxis2Placement3D to IfcOrientationExpression.
      CartesianPositionADDED
      ReferencedByPlacementsDELETED
IFC4x1 Final 4.1.0.0
    IfcLinearPlacementADDED
IFC4x2 Candidate 4.2.0.0
    IfcLinearPlacement
      PlacementRelToXXMODIFIEDType changed from IfcCurve to IfcObjectPlacement.
Instantiation changed to OPTIONAL.
      PlacementMeasuredAlongXXMODIFIEDName changed from Distance to PlacementMeasuredAlong.
Type changed from IfcDistanceExpression to IfcCurve.
      DistanceXXMODIFIEDName changed from Orientation to Distance.
Type changed from IfcOrientationExpression to IfcDistanceExpression.
Instantiation changed from OPTIONAL.
      OrientationXXMODIFIEDName changed from CartesianPosition to Orientation.
Type changed from IfcAxis2Placement3D to IfcOrientationExpression.
      CartesianPositionADDED
      ReferencedByPlacementsDELETED
Semantic definitions at the entity
Entity definition

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 such as IfcAlignmentCurve.

Attribute definitions
#AttributeTypeCardinalityDescription G
2PlacementMeasuredAlongIfcCurve X
3DistanceIfcDistanceExpression X
4OrientationIfcOrientationExpression? X
5CartesianPositionIfcAxis2Placement3D? X
Inherited definitions from supertypes
Entity inheritance IfcLinearPlacementWithInclination IfcLinearSpanPlacement IfcObjectPlacement
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcObjectPlacement
1PlacementRelToIfcObjectPlacement? 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. X
PlacesObjectIfcProduct
@ObjectPlacement
S[0:?]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.
X
IfcLinearPlacement
2PlacementMeasuredAlongIfcCurve X
3DistanceIfcDistanceExpression X
4OrientationIfcOrientationExpression? X
5CartesianPositionIfcAxis2Placement3D? X
Formal representations
XML Specification
 <xs:element name="IfcLinearPlacement" type="ifc:IfcLinearPlacement" substitutionGroup="ifc:IfcObjectPlacement" nillable="true"/>
 <xs:complexType name="IfcLinearPlacement">
  <xs:complexContent>
   <xs:extension base="ifc:IfcObjectPlacement">
    <xs:sequence>
     <xs:element name="PlacementMeasuredAlong" type="ifc:IfcCurve" nillable="true"/>
     <xs:element name="Distance" type="ifc:IfcDistanceExpression" nillable="true"/>
     <xs:element name="Orientation" type="ifc:IfcOrientationExpression" nillable="true" minOccurs="0"/>
     <xs:element name="CartesianPosition" type="ifc:IfcAxis2Placement3D" nillable="true" minOccurs="0"/>
    </xs:sequence>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcLinearPlacement
 SUPERTYPE OF(ONEOF(IfcLinearPlacementWithInclination, IfcLinearSpanPlacement))
 SUBTYPE OF (IfcObjectPlacement);
  PlacementMeasuredAlong : IfcCurve;
  Distance : IfcDistanceExpression;
  Orientation : OPTIONAL IfcOrientationExpression;
  CartesianPosition : OPTIONAL IfcAxis2Placement3D;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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