|modifications||attributes DataValue is_optional||Changed from False to True|
An IfcMetric is used to capture quantitative resultant metrics that can be applied to objectives.
IfcMetric is a subtype of IfcConstraint and may be associated with any subtype of IfcRoot through the IfcRelAssociatesConstraint relationship in the IfcControlExtension schema, or may be associated with IfcProperty by IfcResourceConstraintRelationship.
The aim of IfcMetric is to capture the quantitative aspects of a constraint.
HISTORY New entity in IFC2.0.
IFC4 CHANGE ReferencePath attribute added for indicating the value to be constrained along a path of attribute references.
|1||Name||IfcLabel||A human-readable name to be used for the constraint.|
|2||Description||OPTIONAL IfcText||A human-readable description that may apply additional information about a constraint.|
|3||ConstraintGrade||IfcConstraintEnum||Enumeration that qualifies the type of constraint.|
|4||ConstraintSource||OPTIONAL IfcLabel||Any source material, such as a code or standard, from which the constraint originated.|
|5||CreatingActor||OPTIONAL IfcActorSelect||Person and/or organization that has created the constraint.|
|6||CreationTime||OPTIONAL IfcDateTime||Time when information specifying the constraint instance was created.|
|7||UserDefinedGrade||OPTIONAL IfcLabel||Allows for specification of user defined grade of the constraint beyond the enumeration values (hard, soft, advisory) provided by ConstraintGrade attribute of type IfcConstraintEnum. |
When a value is provided for attribute UserDefinedGrade in parallel the attribute ConstraintGrade shall have enumeration value USERDEFINED.
|HasExternalReferences||SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects||Reference to an external references, e.g. library, classification, or document information, that are associated to the constraint.|
> IFC4 CHANGE New inverse attribute.
|PropertiesForConstraint||SET [0:?] OF IfcResourceConstraintRelationship FOR RelatingConstraint||Reference to the properties to which the constraint is applied.|
|8||Benchmark||IfcBenchmarkEnum||Enumeration that identifies the type of benchmark data.|
|9||ValueSource||OPTIONAL IfcLabel||Reference source for data values. |
If DataValue refers to an IfcTable, this attribute identifies the relevent column identified by IfcTableColumn.Identifier.
|10||DataValue||OPTIONAL IfcMetricValueSelect||The value to be compared on associated objects. A null value indicates comparison to null.|
> IFC4 ADD1 CHANGE This attribute is now optional.
|11||ReferencePath||OPTIONAL IfcReference||Optional path to an attribute to be constrained on associated objects.|
If provided, the metric may be validated by resolving the path to the current value on associated object(s), and comparing such value with DataValue according to the Benchmark.
ENTITY IfcMetric SUBTYPE OF (IfcConstraint); Benchmark : IfcBenchmarkEnum; ValueSource : OPTIONAL IfcLabel; DataValue : OPTIONAL IfcMetricValueSelect; ReferencePath : OPTIONAL IfcReference; END_ENTITY;