IFC 4.3.x development

5.4.3.59 IfcRelVoidsElement

Change log

IFC4

modificationssupertypeChanged from IfcRelConnects to IfcRelDecomposes

5.4.3.59.1 Semantic definitions at the entity

IfcRelVoidsElement is an objectified relationship between a building element and one opening element that creates a void in the element. It is a one-to-one relationship. This relationship implies a Boolean operation of subtraction between the geometric bodies of the element and the opening.

As shown in Figure 1, the insertion of a void into a wall is represented by the relationship IfcRelVoidsElement. The opening is created within the wall by IfcWall(StandardCase) o-- IfcRelVoidsElement --o IfcOpeningElement.

"relationships for voiding"

HISTORY  New entity in IFC1.0

5.4.3.59.1 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
IfcRelVoidsElement
5RelatingBuildingElementIfcElement Reference to element in which a void is created by associated feature subtraction element.

> IFC2x CHANGE  The data type has been changed from IfcBuildingElement to IfcElement with upward compatibility for file based exchange.
6RelatedOpeningElement IfcFeatureElementSubtractionReference to the feature subtraction element which defines a void in the associated element.

> IFC2x CHANGE  The data type has been changed from IfcOpeningElement to IfcFeatureElementSubtraction with upward compatibility for file based exchange.

5.4.3.59.2 Entity inheritance

dot_inheritance IfcRelVoidsElement IfcRelVoidsElement IfcRelDecomposes IfcRelDecomposes IfcRelVoidsElement->IfcRelDecomposes IfcRelDecomposes_children 4 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

5.4.3.59.3 Definitions applying to General Usage

5.4.3.59.3.1 Identity

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

5.4.3.59.3.2 Revision Control

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

5.4.3.59.4 Formal representations

ENTITY IfcRelVoidsElement
 SUBTYPE OF (IfcRelDecomposes);
	RelatingBuildingElement : IfcElement;
	RelatedOpeningElement : IfcFeatureElementSubtraction;
END_ENTITY;