5.4.3.17 IfcFeatureElement

Modifikator (geometrischer Körper)

A feature element is a generalization of all existence dependent elements which modify the shape and appearance of the associated master element. The IfcFeatureElement offers the ability to handle shape modifiers as semantic objects within the IFC object model.

NOTE  The term "feature" has a predefined meaning in a context of "feature-based modeling" and within steel construction work. It is introduced here in a broader sense to cover all existence dependent, but semantically described, modifiers of an element's shape and appearance. It is envisioned that future releases enhance the feature-based capabilities of the IFC model.

In contrary to the aggregation, as used in IfcElementAssembly, that defines the aggregate as a container element, that has equally treated parts, the feature concept introduced by IfcFeatureElement defines the master element with subordinate parts as additions, or with voids or cut-outs as subtractions.

HISTORY  New entity in IFC2x2.
IFC2x2 CHANGE  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.

Common Use Definitions

The following concepts are inherited at supertypes:

 Instance diagram

Spatial Containment

The Spatial Containment concept applies to this entity.

As a subordinate part being fully dependent on the master element the IfcFeatureElement shall have no independent containment relationship to the spatial structure.




XSD Specification:

 <xs:element name="IfcFeatureElement" type="ifc:IfcFeatureElement" abstract="true" substitutionGroup="ifc:IfcElement" nillable="true"/>
 <xs:complexType name="IfcFeatureElement" abstract="true">
  <xs:complexContent>
   <xs:extension base="ifc:IfcElement"/>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcFeatureElement
ABSTRACT SUPERTYPE OF(ONEOF(IfcFeatureElementAddition, IfcFeatureElementSubtraction, IfcSurfaceFeature))
SUBTYPE OF IfcElement;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Inheritance Graph:

ENTITY IfcFeatureElement
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcObjectDefinition
INVERSE
HasAssignments : SET OF IfcRelAssigns FOR RelatedObjects;
Nests : SET [0:1] OF IfcRelNests FOR RelatedObjects;
IsNestedBy : SET OF IfcRelNests FOR RelatingObject;
HasContext : SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
IsDecomposedBy : SET OF IfcRelAggregates FOR RelatingObject;
Decomposes : SET [0:1] OF IfcRelAggregates FOR RelatedObjects;
HasAssociations : SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject
ObjectType : OPTIONAL IfcLabel;
INVERSE
IsDeclaredBy : SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects;
Declares : SET OF IfcRelDefinesByObject FOR RelatingObject;
IsTypedBy : SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;
IsDefinedBy : SET OF IfcRelDefinesByProperties 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;
IsInterferedByElements : SET OF IfcRelInterferesElements FOR RelatedElement;
InterferesElements : SET OF IfcRelInterferesElements FOR RelatingElement;
HasProjections : SET OF IfcRelProjectsElement FOR RelatingElement;
ReferencedInStructures : SET OF IfcRelReferencedInSpatialStructure FOR RelatedElements;
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
END_ENTITY;

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