IfcAnnotationSymbolOccurrence

Definition from ISO/CD 10303-46:1992: An annotation symbol occurrence is a symbol with a style assignment.

> NOTE Corresponding STEP name: annotation_symbol_occurrence. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.

Definition from IAI: The IfcAnnotationSymbolOccurrence shall only be used within a material or paper space dependent representation (note: paper space is not yet supported within this IFC release). Styled symbols within model space shall use IfcStyledItem as the instance to link the geometric symbol representation item to the (shared) style information.

An IfcAnnotationSymbolOccurrence is a relation object, that assigns a (set of) styles to a representation item. It can be used without having a geometric representation item already assigned, e.g. within an IfcMaterialDefinitionRepresentation. If it has a geometric representation item already assigned than this is further restricted to be a subtype of IfcDefinedSymbol. The applicable style information is restricted to be an IfcSymbolStyle. For each instance of a styled symbol, one instance of IfcAnnotationSymbolOccurrence has to be created, that points, via an IfcPresentationStyleAssignment, to an IfcSymbolStyle, that can be shared by many styled symbols.

> HISTORY New entity in Release IFC2x Edition 2.

EXPRESS specification:

ENTITY IfcAnnotationSymbolOccurrence
SUBTYPE OF ( | IfcAnnotationOccurrence);
WHERE
WR31 | : | NOT(EXISTS(SELF\IfcStyledItem.Item)) OR ('IFCPRESENTATIONDEFINITIONRESOURCE.IFCDEFINEDSYMBOL' IN TYPEOF (SELF\IfcStyledItem.Item));
END_ENTITY;

Formal Propositions:

WR31 | : | The Item that is styled by an IfcAnnotationSymbolOccurrence relation shall be (if provided) an IfcDefinedSymbol. NOTE If no Item is provided, the IfcAnnotationSymbolOccurrence is used to provide a symbol style to a material dependent presentation.

Inheritance graph

ENTITY IfcAnnotationSymbolOccurrence;
ENTITY IfcRepresentationItem;
INVERSE
LayerAssignments | : | SET OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem | : | SET [0:1] OF IfcStyledItem FOR Item;
ENTITY IfcStyledItem;
Item | : | OPTIONAL IfcRepresentationItem;
Styles | : | SET [1:?] OF IfcPresentationStyleAssignment;
Name | : | OPTIONAL IfcLabel;
ENTITY IfcAnnotationOccurrence;
ENTITY IfcAnnotationSymbolOccurrence;
END_ENTITY;