IfcAnnotationSurface

Definition from IAI: An IfcAnnotationSurface is a surface or solid with texture coordinates assigned. It provides the capabilities to assign

- surface shading information,
- surface rendering information
- surface lighting information
- surface textures

to a surface, or all surfaces of a face based surface model, a shell based surface model, or a solid model. If the assigned IfcSurfaceStyle defines textures by including an instance of IfcSurfaceStyleWithTextures, the attribute TextureCoordinates determines the mapping of the texture to the surface(s) of the Item. In case of vertex based geometry, texture maps may be used to define the texture coordinates for each face.

The style information is linked by using the IfcStyledItem to the IfcAnnotationSurface instance.

> 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 3.

EXPRESS specification:

ENTITY IfcAnnotationSurface
SUBTYPE OF ( | IfcGeometricRepresentationItem);
Item | : | IfcGeometricRepresentationItem;
TextureCoordinates | : | OPTIONAL IfcTextureCoordinate;
WHERE
WR01 | : | SIZEOF([ 'IFCGEOMETRYRESOURCE.IFCSURFACE', 'IFCGEOMETRICMODELRESOURCE.IFCSHELLBASEDSURFACEMODEL', 'IFCGEOMETRICMODELRESOURCE.IFCFACEBASEDSURFACEMODEL', 'IFCGEOMETRICMODELRESOURCE.IFCSOLIDMODEL', 'IFCGEOMETRICMODELRESOURCE.IFCBOOLEANRESULT', 'IFCGEOMETRICMODELRESOURCE.IFCCSGPRIMITIVE3D'] * TYPEOF(Item) ) >= 1;
END_ENTITY;

Attribute definitions:

Item | : | Geometric representation item, providing the geometric definition of the annotated surface. It is further restricted to be a surface, surface model, or solid model.
TextureCoordinates | : | Texture coordinates, such as a texture map, that are associated with the textures for the surface style. It should only be given, if the IfcSurfaceStyle associated to the IfcAnnotationSurfaceOccurrence contains an IfcSurfaceStyleWithTextures.

Formal Propositions:

WR01 | : | Only surfaces, surface models, solids and 3D primitives and CSG results are applicable as Items.

Inheritance graph

ENTITY IfcAnnotationSurface;
ENTITY IfcRepresentationItem;
INVERSE
LayerAssignments | : | SET OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem | : | SET [0:1] OF IfcStyledItem FOR Item;
ENTITY IfcGeometricRepresentationItem;
ENTITY IfcAnnotationSurface;
Item | : | IfcGeometricRepresentationItem;
TextureCoordinates | : | OPTIONAL IfcTextureCoordinate;
END_ENTITY;