IfcRepresentationItem

Definition from ISO/CD 10303-43:1992: A representation item is an element of product data that participates in one or more representations or contributes to the definition of another representation item. A representation item contributes to the definition of another representation item when it is referenced by that representation item.

Definition from IAI The IfcRepresentationItem is used within (and only within - directly or indirectly through other IfcRepresentationItem's or IfcShapeAspect's) an IfcRepresentation to represent an IfcProductRepresentation. Most commonly these IfcRepresentationItem's are geometric or topological representation items, that can (but not need to) have presentation style infomation assigned.

NOTE Corresponding STEP entity: representation_item. Please refer to ISO/IS 10303-43:1994, for the final definition of the formal standard. The following changes have been made: The attribute 'name' and the WR1 have not been incorporated.

HISTORY New entity in IFC Release 2x.
IFC2x Edition 3 CHANGE The inverse attributes StyledByItem and LayerAssignments have been added. Upward compatibility for file based exchange is guaranteed.
EXPRESS specification:

ENTITY IfcRepresentationItem

ABSTRACT SUPERTYPE OF (ONEOF(IfcTopologicalRepresentationItem, IfcGeometricRepresentationItem, IfcMappedItem, IfcStyledItem));

INVERSE

LayerAssignments : SET OF IfcPresentationLayerAssignment FOR AssignedItems;

StyledByItem : SET [0:1] OF IfcStyledItem FOR Item;

END_ENTITY;

Attribute definitions:

LayerAssignments : Assignment of the representation item to a single or multiple layer(s). The LayerAssigments can override a LayerAssigments of the IfcRepresentation it is used within the list of Items.
NOTE Implementation agreements can restrict the maximum number of layer assignments to 1.
IFC2x Edition 3 CHANGE The inverse attribute LayerAssignments has been added.

StyledByItem : Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.
IFC2x Edition 3 CHANGE The inverse attribute StyledByItem has been added.

Inheritance graph

ENTITY IfcRepresentationItem;

ENTITY IfcRepresentationItem;

INVERSE

LayerAssignments : SET OF IfcPresentationLayerAssignment FOR AssignedItems;

StyledByItem : SET [0:1] OF IfcStyledItem FOR Item;

END_ENTITY;

LayerAssignments	:	Assignment of the representation item to a single or multiple layer(s). The LayerAssigments can override a LayerAssigments of the IfcRepresentation it is used within the list of Items. NOTE Implementation agreements can restrict the maximum number of layer assignments to 1. IFC2x Edition 3 CHANGE The inverse attribute LayerAssignments has been added.
StyledByItem	:	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. IFC2x Edition 3 CHANGE The inverse attribute StyledByItem has been added.