The IfcRelProjectsElement is an objectified relationship between an element and one projection element that creates a modifier to the shape of the element. The relationship is defined to be a 1:1 relationship, if an element has more than one projection, several relationship objects have to be used, each pointing to a different projection element. The IfcRelProjectsElement establishes an aggregation relationship between the main element and a sub ordinary addition feature.
NOTE In contrary the IfcRelAggregates relationship established an aggregation of equal parts to a whole.
The IfcRelProjectsElement implies a Boolean operation of addition for the geometric bodies of the element and the feature element. As with all decomposition relationships it determines:
HISTORY New entity in IFC2x2.
IFC4 CHANGE Supertype changed to IfcRelDecomposes.
|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.|
|5||RelatingElement||IfcElement||Element at which a projection is created by the associated IfcProjectionElement.|
|6||RelatedFeatureElement||IfcFeatureElementAddition||Reference to the IfcFeatureElementAddition that defines an addition to the volume of the element, by using a Boolean addition operation. An example is a projection at the associated element.|
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 IfcRelProjectsElement SUBTYPE OF (IfcRelDecomposes); RelatingElement : IfcElement; RelatedFeatureElement : IfcFeatureElementAddition; END_ENTITY;