IfcAnnotationSurfaceOccurrence

Definition from IAI: The IfcAnnotationSurfaceOccurrence shall only be used within a material or paper space dependent representation (note: paper space is not yet supported within this IFC release). Styled surfaces or solids within model space shall use IfcStyledItem as the instance to link the geometric surface, solid or annotation surface (for texture maps) representation item to the (shared) style information.

An IfcAnnotationSurfaceOccurrence 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. Each instance of IfcAnnotationSurfaceOccurrence points, via an IfcPresentationStyleAssignment, to an IfcSurfaceStyle, that can be shared by many styled surfaces, or solids.

> NOTE No direct corresponding STEP entity, the entity has been defined in analogy to the other annotation occurrence entity.

> HISTORY New entity in Release IFC2x Edition 2.

EXPRESS specification:

ENTITY IfcAnnotationSurfaceOccurrence
SUBTYPE OF ( | IfcAnnotationOccurrence);
WHERE
WR31 | : | NOT(EXISTS(SELF\IfcStyledItem.Item)) OR (SIZEOF( ['IFCGEOMETRYRESOURCE.IFCSURFACE', 'IFCGEOMETRICMODELRESOURCE.IFCFACEBASEDSURFACEMODEL', 'IFCGEOMETRICMODELRESOURCE.IFCSHELLBASEDSURFACEMODEL', 'IFCGEOMETRICMODELRESOURCE.IFCSOLIDMODEL'] * TYPEOF(SELF\IfcStyledItem.Item)) > 0);
END_ENTITY;

Formal Propositions:

WR31 | : | The Item that is styled by an IfcAnnotationSurfaceOccurrence relation shall be (if provided) a subtype of IfcSurface, IfcSolidModel, IfcShellBasedSurfaceModel, IfcFaceBasedSurfaceModel. NOTE If no Item is provided, the IfcAnnotationSurfaceOccurrence is used to provide a surface style to a material dependent presentation.

Inheritance graph

ENTITY IfcAnnotationSurfaceOccurrence;
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 IfcAnnotationSurfaceOccurrence;
END_ENTITY;