5.4.3.62 IfcRelVoidsElement
5.4.3.62.1 Semantic definition
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 5.4.3.62.A, the insertion of a void into a wall is represented by the relationship IfcRelVoidsElement. The opening within the wall is defined by the pattern IfcWall - IfcRelVoidsElement - IfcOpeningElement.
5.4.3.62.2 Entity inheritance
5.4.3.62.3 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, Only the last modification is stored - either as addition, deletion or modification. 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. |
| Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
| IfcRelVoidsElement (2) | |||
| 5 | RelatingBuildingElement | IfcElement |
Reference to the element in which a void is created by the associated feature subtraction element. 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. The data type has been changed from IfcOpeningElement to IfcFeatureElementSubtraction with upward compatibility for file based exchange. |
5.4.3.62.4 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 | |||
5.4.3.62.5 Examples
5.4.3.62.6 Formal representation
ENTITY IfcRelVoidsElement
SUBTYPE OF (IfcRelDecomposes);
RelatingBuildingElement : IfcElement;
RelatedOpeningElement : IfcFeatureElementSubtraction;
END_ENTITY;