5.4.3.38 IfcRelReferencedInSpatialStructure

Bezieht sich auf eine räumliche Struktur - Relation

The objectified relationship, IfcRelReferencedInSpatialStructure is used to assign elements in addition to those levels of the project spatial structure, in which they are referenced, but not primarily contained. 

NOTE  The primary containment relationship between an element and the spatial structure is handled by IfcRelContainsInSpatialStructure.

Any element can be referenced to zero, one or several levels of the spatial structure. Whereas the IfcRelContainsInSpatialStructure relationship is required to be hierarchical (an element can only be contained in exactly one spatial structure element), the IfcRelReferencedInSpatialStructure is not restricted to be hierarchical.

EXAMPLE  A wall might be normally contained within a storey, and since it does not span through several stories, it is not referenced in any additional storey. However a curtain wall might span through several stories, in this case it can be contained within the ground floor, but it would be referenced by all additional stories, it spans.

Predefined spatial structure elements to which elements can be assigned are

Elements can also be references in a spatial zone that is provided as IfcSpatialZone.

The same element can be assigned to different spatial structure elements depending on the context.

HISTORY  New entity in IFC2x3.

Use Definition

Figure 132 shows the use of IfcRelContainedInSpatialStructure and IfcRelReferencedInSpatialStructure to assign an IfcCurtainWall to two different levels within the spatial structure. It is primarily contained within the ground floor, and additionally referenced within the first and second floor.

reference and containment

Figure 132 — Relationship for spatial structure referencing


XSD Specification:

 <xs:element name="IfcRelReferencedInSpatialStructure" type="ifc:IfcRelReferencedInSpatialStructure" substitutionGroup="ifc:IfcRelConnects" nillable="true"/>
 <xs:complexType name="IfcRelReferencedInSpatialStructure">
  <xs:complexContent>
   <xs:extension base="ifc:IfcRelConnects">
    <xs:sequence>
     <xs:element name="RelatedElements">
      <xs:complexType>
       <xs:sequence>
        <xs:element ref="ifc:IfcProduct" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcProduct"/>
       <xs:attribute ref="ifc:cType" fixed="set"/>
       <xs:attribute ref="ifc:arraySize" use="optional"/>
      </xs:complexType>
     </xs:element>
     <xs:element name="RelatingStructure" type="ifc:IfcSpatialElement" nillable="true"/>
    </xs:sequence>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcRelReferencedInSpatialStructure
SUBTYPE OF IfcRelConnects;
RelatedElements : SET [1:?] OF IfcProduct;
RelatingStructure : IfcSpatialElement;
WHERE
WR31 : SIZEOF(QUERY(temp <* RelatedElements | 'IFCPRODUCTEXTENSION.IFCSPATIALSTRUCTUREELEMENT' IN TYPEOF(temp))) = 0;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

RelatedElements : Set of products, which are referenced within this level of the spatial structure hierarchy.
NOTE  Referenced elements are contained elsewhere within the spatial structure, they are referenced additionally by this spatial structure element, e.g., because they span several stories.
RelatingStructure : Spatial structure element, within which the element is referenced. Any element can be contained within zero, one or many elements of the project spatial and zoning structure.
IFC4 CHANGE  The attribute RelatingStructure as been promoted to the new supertype IfcSpatialElement with upward compatibility for file based exchange.

Formal Propositions:

WR31 : The relationship object shall not be used to include other spatial structure elements into a spatial structure element. The hierarchy of the spatial structure is defined using IfcRelAggregates.

Inheritance Graph:

ENTITY IfcRelReferencedInSpatialStructure
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcRelationship
ENTITY IfcRelConnects
ENTITY IfcRelReferencedInSpatialStructure
RelatedElements : SET [1:?] OF IfcProduct;
RelatingStructure : IfcSpatialElement;
END_ENTITY;

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