IfcQuantitySet is the the abstract supertype for all quantity sets attached to objects. The quantity set is a container class that holds the individual quantities within a quantity tree. These quantities are interpreted according to their name attribute and classified according to their measure type. Some quantity sets are included in the IFC specification and have a predefined set of quantities indicated by assigning a significant name. These quantity sets are listed as "quantity sets" within this specification. Quantity sets applicable to certain objects are listed in the object specification.
An IfcPropertySetTemplate may define the underlying structure, i.e. the required name, the applicable object or object types to which the quantity set can be attached, and the individual quantities that maybe included. Quantity sets are related to other objects by using the relationship object that refers to the corresponding object:
HISTORY New entity in IFC4.
|1||GlobalId||IfcGloballyUniqueId||Assignment of a globally unique identifier within the entire software world.|
|2||OwnerHistory||OPTIONAL IfcOwnerHistory||Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, |
> NOTE only the last modification in stored - either as addition, deletion or modification.
> IFC4 CHANGE The attribute has been changed to be OPTIONAL.
|3||Name||OPTIONAL IfcLabel||Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule.|
|4||Description||OPTIONAL IfcText||Optional description, provided for exchanging informative comments.|
|HasContext||SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions|
|HasAssociations||SET [0:?] OF IfcRelAssociates FOR RelatedObjects||Reference to the relationship IfcRelAssociates and thus to those externally defined concepts, like classifications, documents, or library information, which are associated to the property definition.|
|DefinesType||SET [0:?] OF IfcTypeObject FOR HasPropertySets||The type object to which the property set is assigned. The property set acts as a shared property set to all occurrences of the type object.|
> NOTE The relationship between the IfcPropertySetDefinition and the IfcTypeObject is a direct relationship, not utilizing IfcRelDefinesByProperties, for maintaining compatibility with earlier releases of this standard.
> IFC4 CHANGE The cardinality has been changed from 0:1 to 0:? with upward compatibility for file based exchange.
|IsDefinedBy||SET [0:?] OF IfcRelDefinesByTemplate FOR RelatedPropertySets||Relation to the property set template, via the objectified relationship IfcRelDefinesByTemplate, that, if given, provides the definition template for the property set or quantity set and its properties. |
> IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.
|DefinesOccurrence||SET [0:?] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition||Reference to the relation to one or many object occurrences that are characterized by the property set definition. A single property set can be assigned to multiple object occurrences using the objectified relationship IfcRefDefinesByProperties.|
> IFC4 CHANGE Inverse attribute renamed from PropertyDefinitionOf with upward compatibility for file-based exchange.
IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.
Ownership, history, and merge state is captured using IfcOwnerHistory.
ENTITY IfcQuantitySet ABSTRACT SUPERTYPE OF (ONEOF (IfcElementQuantity)) SUBTYPE OF (IfcPropertySetDefinition); END_ENTITY;