5.4.3.56 IfcRelProjectsElement
5.4.3.56.1 Semantic definition
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.
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:
- existence dependency - the RelatedFeatureElement cannot exist without the RelatingElement
- hierarchical and non-cyclical relationship - the IfcRelProjectsElement can only alter a single IfcElement
- no spatial containment - the IfcFeatureElementAddition as related element never participates in the hiearchical spatial containment relationship IfcRelContainedInSpatialStructure
5.4.3.56.2 Entity inheritance
5.4.3.56.3 Attributes
| # | Attribute | Type | Description |
|---|---|---|---|
| IfcRoot (4) | |||
| 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, |
| 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. |
| Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
| IfcRelProjectsElement (2) | |||
| 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. |
5.4.3.56.4 Concept usage
| Concept | Usage | Description | |
|---|---|---|---|
| IfcRoot (2) | |||
| Revision Control | General |
Ownership, history, and merge state is captured using IfcOwnerHistory. |
|
| Software Identity | General |
IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept. |
|
| Click to show 2 hidden inherited concepts Click to hide 2 inherited concepts | |||
5.4.3.56.5 Formal representation
ENTITY IfcRelProjectsElement
SUBTYPE OF (IfcRelDecomposes);
RelatingElement : IfcElement;
RelatedFeatureElement : IfcFeatureElementAddition;
END_ENTITY;