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.

Containment use definition

The containment to the spatial structure is defined at the level of the supertype IfcFeatureElement

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 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
HasStructuralMember | : | SET OF IfcRelConnectsStructuralElement FOR RelatingElement;
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;
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;