Class Ifc4x2::IfcRepresentationItem

Nested Relationships

This class is a nested type of Struct Ifc4x2.

Inheritance Relationships

Base Type

Derived Types

Class Documentation

class Ifc4x2::IfcRepresentationItem : public IfcUtil::IfcBaseEntity

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.

NOTE Corresponding entity in ISO 10303-43:1994: 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.

The IfcRepresentationItem is used within an IfcRepresentation (directly or indirectly through other IfcRepresentationItem’s) 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 The assignment of a style is only applicable to the subtypes IfcGeometricRepresentationItem, IfcMappedItem and some selected subtypes of IfcTopologicalRepresentationItem (IfcVertexPoint, IfcEdgeCurve, IfcFaceSurface).

In case that presentation style information is applied, it can be either applied by an IfcStyledItem, or by an assignment to an IfcPresentationLayerWithStyle. If both are present, and both style assignments include the same subtype of IfcPresentationStyle, then the style assigned by IfcStyledItem takes priority.

Figure 281 shows an instance diagram explaining the use of IfcStyledItem and IfcPresentationLayerWithStyle to apply presentation styles.

EXAMPLE The assignment of style information by a styled item and a presentation layer with style. Since the presentation styles are different, IfcCurveStyle and IfcSurfaceStyle, both are applied to the geometric representation item.

Figure 281 — Representation item style

Figure 282 shows in instance diagram explaining the override of IfcPresentationLayerWithStyle by IfcStyledItem to apply presentation styles.

EXAMPLE The assignment of style information by a styled item and a presentation layer with style. Since the presentation styles for curve style are aprovided by both, the IfcCurveStyle provided by the IfcStyledItem overrides the IfcCurveStyle provided by the IfcPresentationLayerWithStyle

Figure 282 — Representation item style override

HISTORY New entity in IFC Release 2x.

IFC2x3 CHANGE The inverse attributes StyledByItem and LayerAssignments have been added. Upward compatibility for file based exchange is guaranteed.

Subclassed by Ifc4x2::IfcGeometricRepresentationItem, Ifc4x2::IfcMappedItem, Ifc4x2::IfcStyledItem, Ifc4x2::IfcTopologicalRepresentationItem

Public Types

typedef IfcTemplatedEntityList<IfcRepresentationItem> list

Public Functions

IfcTemplatedEntityList<IfcPresentationLayerAssignment>::ptr LayerAssignment() const
IfcTemplatedEntityList<IfcStyledItem>::ptr StyledByItem() const
const IfcParse::entity &declaration() const
IfcRepresentationItem(IfcEntityInstanceData *e)

Public Static Functions

const IfcParse::entity &Class()