IFC 4.3.x development

5.4.3.46 IfcRelProjectsElement

Change log

IFC4

modificationssupertypeChanged from IfcRelConnects to IfcRelDecomposes

5.4.3.46.1 Semantic definitions at the entity

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.

5.4.3.46.1 Attributes

#Attribute Type Description
IfcRoot
1GlobalId IfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world.
2OwnerHistory 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.
3Name 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.
4Description OPTIONAL IfcText Optional description, provided for exchanging informative comments.
IfcRelationship
IfcRelDecomposes
IfcRelProjectsElement
5RelatingElement IfcElement Element at which a projection is created by the associated IfcProjectionElement.
6RelatedFeatureElementIfcFeatureElementAdditionReference 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.

5.4.3.46.2 Entity inheritance

dot_inheritance IfcRelProjectsElement IfcRelProjectsElement IfcRelDecomposes IfcRelDecomposes IfcRelProjectsElement->IfcRelDecomposes IfcRelDecomposes_children 3 more... IfcRelDecomposes_children->IfcRelDecomposes IfcRelationship IfcRelationship IfcRelDecomposes->IfcRelationship IfcRelationship_children 5 more... IfcRelationship_children->IfcRelationship IfcRoot IfcRoot IfcRelationship->IfcRoot IfcObjectDefinition IfcObjectDefinition IfcObjectDefinition->IfcRoot IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot

5.4.3.46.3 Definitions applying to General Usage

5.4.3.46.3.1 Identity

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

5.4.3.46.3.2 Revision Control

Ownership, history, and merge state is captured using IfcOwnerHistory.

5.4.3.46.4 Formal representations

ENTITY IfcRelProjectsElement
 SUBTYPE OF (IfcRelDecomposes);
	RelatingElement : IfcElement;
	RelatedFeatureElement : IfcFeatureElementAddition;
END_ENTITY;