The IfcFaceBasedSurfaceModel represents the a shape by connected face sets. The connected faces have a dimensionality 2 and are placed in a coordinate space of dimensionality 3.
NOTE Definition according to ISO/CD 10303-42:1992
A face based surface model is described by a set of connected face sets of dimensionality 2. The connected face sets shall not intersect except at edges and vertices, except that a face in one connected face set may overlap a face in another connected face set, provided the face boundaries are identical. There shall be at least one connected face set.
A connected face set may exist independently of a surface model.
NOTE Entity adapted from face_based_surface_model defined in ISO 10303-42.
HISTORY New entity in IFC2x.
IFC4 CHANGE The entity has been deprecated and shall not be used. The entity IfcFacetedBrep shall be used instead.
|LayerAssignment||SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems||Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.|
> IFC2x3 CHANGE The inverse attribute LayerAssignments has been added.
> IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
|StyledByItem||SET [0:1] OF IfcStyledItem FOR Item||Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.|
> IFC2x3 CHANGE The inverse attribute StyledByItem has been added.
|1||FbsmFaces||SET [1:?] OF IfcConnectedFaceSet||The set of connected face sets comprising the face based surface model.|
|Dim||INVALID||The space dimensionality of this class, it is always 3.|
ENTITY IfcFaceBasedSurfaceModel SUBTYPE OF (IfcGeometricRepresentationItem); FbsmFaces : SET [1:?] OF IfcConnectedFaceSet; DERIVE Dim : IfcDimensionCount := 3; END_ENTITY;