IfcGroup

Definition from IAI: The IfcGroup is an generalization of any arbitrary group. A group is a logical collection of objects. It does not have its own position, nor can it hold its own shape representation. Therefore a group is an aggregation under some non-geometrical / topological grouping aspects.

> NOTE Use IfcRelDecomposes together with the appropriate subtypes of IfcProduct to define an aggregation of products that may have its own position and shape representation.
> EXAMPLE An example for a group is the system, since it groups elements under the aspect of their role, regardless of their position in a building.

A group can hold any collection of objects (being products, processes, controls, resources, actors or other groups). Thus groups can be nested. An object can be part of zero, one, or many groups. Grouping relationships are not required to be hierarchical.

> NOTE Use IfcRelDecomposes together with the appropriate subtypes of IfcProduct to define an hierarchical aggregation of products.

The group collection is handled by an instance of IfcRelAssignsToGroup, which assigns all group members to the IfcGroup.

> HISTORY New entity in IFC Release 1.0.

EXPRESS specification:

ENTITY IfcGroup
SUBTYPE OF ( | IfcObject);
INVERSE
IsGroupedBy | : | IfcRelAssignsToGroup FOR RelatingGroup;
END_ENTITY;

Attribute definitions:

IsGroupedBy | : | Contains the relationship that assigns the group members to the group object.

Inheritance graph

ENTITY IfcGroup;
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 IfcGroup;
INVERSE
IsGroupedBy | : | IfcRelAssignsToGroup FOR RelatingGroup;
END_ENTITY;