IfcAnnotationFillAreaOccurrence

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

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

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

An IfcAnnotationFillAreaOccurrence 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 IfcAnnotationFillArea. The applicable style information is restricted to be an IfcFillAreaStyle. For each instance of a styled fill area, one instance of IfcAnnotation FillArea Occurrence has to be created, that points, via an IfcPresentationStyleAssignment, to an Ifc FillArea Style, that can be shared by many styled fill areas.

The IfcAnnotationFillAreaOccurrence determines how an IfcFillAreaStyle, and in particular how an included IfcFillAreaStyleHatching or IfcFillAreaStyleTiles, is placed at a particular annotation occurrence. The FillStyleTarget specifies the point (if omitted it defaults to the origin) at which the (virtual) point of origin of the hatching style is placed, it can either be:

- a point relative to the world coordinate system (if GlobalOrLocal = .GLOBAL.), or
- a point relative to the local (object) coordinate system (if GlobalOrLocal = .LOCAL.), or
- a point relative to the surface parameterization (if GlobalOrLocal is omitted).

> HISTORY New entity in Release IFC2x Edition 2.
> IFC2x Edition 3 CHANGE The IfcAnnotationFillAreaOccurrence has changed by making the attribute FillStyleTarget OPTIONAL and by adding the attribute GlobalOrLocal.

EXPRESS specification:

ENTITY IfcAnnotationFillAreaOccurrence
SUBTYPE OF ( | IfcAnnotationOccurrence);
FillStyleTarget | : | OPTIONAL IfcPoint;
GlobalOrLocal | : | OPTIONAL IfcGlobalOrLocalEnum;
WHERE
WR31 | : | NOT(EXISTS(SELF\IfcStyledItem.Item)) OR ('IFCPRESENTATIONDEFINITIONRESOURCE.IFCANNOTATIONFILLAREA' IN TYPEOF (SELF\IfcStyledItem.Item));
END_ENTITY;

Attribute definitions:

FillStyleTarget | : | The point that specifies the starting location for the fill area style assigned to the annotation fill area occurrence. Depending on the attribute GlobalOrLocal the point is either given within the world coordinate system of the project or within the object coordinate system of the element or annotation. If the FillStyleTarget is not given, it defaults to 0.,0. IFC2x Edition 3 CHANGE The attribute has been made OPTIONAL.
GlobalOrLocal | : | The coordinate system in which the FillStyleTarget point is given. Depending on the attribute GlobalOrLocal the point is either given within the world coordinate system of the project or within the object coordinate system of the element or annotation. If not given, the hatch style is directly applied to the parameterization of the geometric representation item, e.g. to the surface coordinate sytem, defined by the surface normal. IFC2x Edition 3 CHANGE The attribute has been added.

Formal Propositions:

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

Inheritance graph

ENTITY IfcAnnotationFillAreaOccurrence;
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 IfcAnnotationFillAreaOccurrence;
FillStyleTarget | : | OPTIONAL IfcPoint;
GlobalOrLocal | : | OPTIONAL IfcGlobalOrLocalEnum;
END_ENTITY;