IfcFeatureElementAddition

Definition from IAI: A specialization of the general feature element, that represents an existence dependent element which modifies the shape and appearance of the associated master element. The IfcFeatureElementAddition offers the ability to handle shape modifiers as semantic objects within the IFC object model that add to the shape of the master element.

HISTORY: New entity in Release IFC2x Edition 2.
NOTE: The entity is introduced as an upward compatible extension of the IFC2x platform. It is an intermediate abstract supertype without defining its own explicit attributes.

The IfcFeatureElementAddition is associated to its master element by virtue of the objectified relationship IfcRelProjectsElement. This relationship implies a Boolean 'union' operation between the shape of the master element and the shape of the addition feature.

Geometry Use Definitions

The geometric representation of IfcFeatureElementAddition is given by the IfcProductDefinitionShape, allowing multiple geometric representations.

Local Placement

The local placement for IfcFeatureElementAddition is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations. The local placement is always defined in relation to the local placement of the element to which the feature element is added:

The PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcElement, which is used in the HasAdditionFeature.RelatingElement inverse attribute.

Shape Representation

The geometry use definitions for the shape representation of the IfcFeatureElementAddition is given at the level of its subtypes.

EXPRESS specification:

ENTITY IfcFeatureElementAddition

ABSTRACT SUPERTYPE OF

(IfcProjectionElement)

SUBTYPE OF (

IfcFeatureElement);

INVERSE

ProjectsElements

IfcRelProjectsElement FOR RelatedFeatureElement;

END_ENTITY;

Attribute definitions:

ProjectsElements

Reference to the IfcRelProjectsElement relationship that uses this IfcFeatureElementAddition to create a volume addition at an element. The IfcFeatureElementAddition can only be used to create a single addition at a single element using Boolean addition operation.

Inheritance graph

ENTITY IfcFeatureElementAddition;

ENTITY IfcRoot;

GlobalId

IfcGloballyUniqueId;

OwnerHistory

IfcOwnerHistory;

Name

OPTIONAL IfcLabel;

Description

OPTIONAL IfcText;

ENTITY IfcObjectDefinition;

INVERSE

HasAssignments

SET OF IfcRelAssigns FOR RelatedObjects;

IsDecomposedBy

SET OF IfcRelDecomposes FOR RelatingObject;

Decomposes

SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;

HasAssociations

SET OF IfcRelAssociates FOR RelatedObjects;

ENTITY IfcObject;

ObjectType

OPTIONAL IfcLabel;

INVERSE

IsDefinedBy

SET OF IfcRelDefines FOR RelatedObjects;

ENTITY IfcProduct;

ObjectPlacement

OPTIONAL IfcObjectPlacement;

Representation

OPTIONAL IfcProductRepresentation;

INVERSE

ReferencedBy

SET OF IfcRelAssignsToProduct FOR RelatingProduct;

ENTITY IfcElement;

Tag

OPTIONAL IfcIdentifier;

INVERSE

FillsVoids

SET [0:1] OF IfcRelFillsElement FOR RelatedBuildingElement;

ConnectedTo

SET OF IfcRelConnectsElements FOR RelatingElement;

HasCoverings

SET OF IfcRelCoversBldgElements FOR RelatingBuildingElement;

HasProjections

SET OF IfcRelProjectsElement FOR RelatingElement;

HasStructuralMember

SET OF IfcRelConnectsStructuralElement FOR RelatingElement;

ReferencedInStructures

SET OF IfcRelReferencedInSpatialStructure FOR RelatedElements;

HasPorts

SET OF IfcRelConnectsPortToElement FOR RelatedElement;

HasOpenings

SET OF IfcRelVoidsElement FOR RelatingBuildingElement;

IsConnectionRealization

SET OF IfcRelConnectsWithRealizingElements FOR RealizingElements;

ProvidesBoundaries

SET OF IfcRelSpaceBoundary FOR RelatedBuildingElement;

ConnectedFrom

SET OF IfcRelConnectsElements FOR RelatedElement;

ContainedInStructure

SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;

ENTITY IfcFeatureElement;

ENTITY IfcFeatureElementAddition;

INVERSE

ProjectsElements

IfcRelProjectsElement FOR RelatedFeatureElement;

END_ENTITY;