|Teil zu Ganzes Beziehung ungeordnet - Relation|
The aggregation relationship IfcRelAggregates is a special type of the general composition/decomposition (or whole/part) relationship
IfcRelDecomposes. The aggregation relationship can be applied to all subtypes of IfcObjectDefinition.
In cases of aggregation of physical elements into a physical aggregate the shape representation of the whole (within the same
representation identifier) can be taken from the sum of the shape representations of the parts.
EXAMPLE A roof is the aggregation of the roof elements, such as roof slabs, rafters, purlins, etc. Within the
same representation identifier (such as the body geometric representation), the shape representation of the roof is given by
the shape representation of its parts.
Decompositions imply a dependency, implying that the whole depends on the definition of the parts and the parts depend
on the existence of the whole. The behaviour that is implied from the dependency relationship has to be established inside the applications.
HISTORY New entity in IFC2x.
IFC4 CHANGE The attributes RelatingObject and RelatedObjects are demoted from the supertype IfcRelDecomposes.
XSD Specification: <xs:element name="IfcRelAggregates" type="ifc:IfcRelAggregates" substitutionGroup="ifc:IfcRelDecomposes" nillable="true"/>
<xs:element name="RelatingObject" type="ifc:IfcObjectDefinition" nillable="true"/>
<xs:element ref="ifc:IfcObjectDefinition" maxOccurs="unbounded"/>
<xs:attribute ref="ifc:itemType" fixed="ifc:IfcObjectDefinition"/>
<xs:attribute ref="ifc:cType" fixed="set"/>
<xs:attribute ref="ifc:arraySize" use="optional"/>
|NoSelfReference|| : ||SIZEOF(QUERY(Temp <* RelatedObjects | RelatingObject :=: Temp)) = 0;|
|RelatingObject|| : ||
The object definition, either an object type or an object occurrence, that represents the aggregation. It is the whole within the whole/part relationship.
IFC4 CHANGE The attribute has been demoted from the supertype IfcRelDecomposes and defines the non-ordered aggregation relationship.
|RelatedObjects|| : ||
The object definitions, either object occurrences or object types, that are being aggregated. They are defined as the parts in the whole/part relationship. No order is implied between the parts.
IFC4 CHANGE The attribute has been demoted from the supertype IfcRelDecomposes and defines the non-ordered set of parts within the aggregation.
|NoSelfReference|| : ||
The instance to with the relation points as provided by RelatingObject shall not be contained in the set of RelatedObjects.
Link to this page