IFC 4.3.x development

5.4.3.52 IfcRelVoidsElement

Change log

5.4.3.52.1 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.

HISTORY  New entity in IFC1.0

5.4.3.52.1 Attributes

#	Attribute	Type	Description
IfcRoot
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.
IfcRelationship
IfcRelDecomposes
IfcRelVoidsElement
5	RelatingBuildingElement	IfcElement	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.
6	RelatedOpeningElement	IfcFeatureElementSubtraction	Reference 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.

5.4.3.52.2 Entity inheritance

5.4.3.52.3 Definitions applying to General Usage

5.4.3.52.3.1 Identity

5.4.3.52.3.2 Revision Control

5.4.3.52.4 Formal representations

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