IfcPreDefinedPropertySet是分配给对象或类型对象的所有静态定义的属性集的泛化。静态或预定义的属性集是具有固定属性列表的实体,这些属性具有特定的定义数据类型。
通过使用引用相应对象的关系对象,属性集与其他对象相关:
引用对象:使用反向属性DefinesOccurrence的IfcRelDefinesByProperties。
类型对象:通过反向属性DefinesType使用直接链接。
可以将IfcPreDefinedPropertySet指派给对象和对象类型,但没有定义属性集模板。
IFC4中增加的新实体
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
IfcRoot | |||||
1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world. | X |
2 | OwnerHistory | IfcOwnerHistory | [0:1] | 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. |
X |
3 | Name | IfcLabel | [0:1] | 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. | X |
4 | Description | IfcText | [0:1] | Optional description, provided for exchanging informative comments. | X |
IfcPropertyDefinition | |||||
HasContext | IfcRelDeclares @RelatedDefinitions |
S[0:1] | X | ||
HasAssociations | IfcRelAssociates @RelatedObjects |
S[0:?] | 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. | X | |
IfcPropertySetDefinition | |||||
DefinesType | IfcTypeObject @HasPropertySets |
S[0:?] | 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. |
X | |
IsDefinedBy | IfcRelDefinesByTemplate @RelatedPropertySets |
S[0:?] | 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. | X | |
DefinesOccurrence | IfcRelDefinesByProperties @RelatingPropertyDefinition |
S[0:?] | 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. | X | |
IfcPreDefinedPropertySet |