IfcFaceBasedSurfaceModel

Natural language names
Flächenmodell (basierend auf Einzelflächen)
Face Based Surface Model
Change log
ItemSPFXMLChangeDescription
IFC4 Addendum 2 Technical Corrigendum 1 4.0.2.1
    IfcFaceBasedSurfaceModelMODIFIEDStatus changed to Deprecated.
IFC4x1 Final 4.1.0.0
    IfcFaceBasedSurfaceModelMODIFIEDStatus changed from Deprecated.
Semantic definitions at the entity
Entity definition

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.

Informal Propositions:

  1. The connected face sets shall not overlap or intersect except at common faces, edges or vertices.
  2. The fbsm faces have dimensionality 2.

IFC4 CHANGE  The entity has been deprecated and shall not be used. The entity IfcFacetedBrep shall be used instead.

Attribute definitions
#AttributeTypeCardinalityDescription G
1FbsmFacesIfcConnectedFaceSetS[1:?] The set of connected face sets comprising the face based surface model. X
Dim
:=3
IfcDimensionCountThe space dimensionality of this class, it is always 3. X
Inherited definitions from supertypes
Entity inheritance IfcGeometricRepresentationItem IfcRepresentationItem
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRepresentationItem
LayerAssignmentIfcPresentationLayerAssignment
@AssignedItems
S[0:1]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.
X
StyledByItemIfcStyledItem
@Item
S[0:1]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.
X
IfcGeometricRepresentationItem
IfcFaceBasedSurfaceModel
1FbsmFacesIfcConnectedFaceSetS[1:?] The set of connected face sets comprising the face based surface model. X
Dim
:=3
IfcDimensionCountThe space dimensionality of this class, it is always 3. X
Formal representations
XML Specification
 <xs:element name="IfcFaceBasedSurfaceModel" type="ifc:IfcFaceBasedSurfaceModel" substitutionGroup="ifc:IfcGeometricRepresentationItem" nillable="true"/>
 <xs:complexType name="IfcFaceBasedSurfaceModel">
  <xs:complexContent>
   <xs:extension base="ifc:IfcGeometricRepresentationItem">
    <xs:sequence>
     <xs:element name="FbsmFaces">
      <xs:complexType>
       <xs:sequence>
        <xs:element ref="ifc:IfcConnectedFaceSet" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcConnectedFaceSet"/>
       <xs:attribute ref="ifc:cType" fixed="set"/>
       <xs:attribute ref="ifc:arraySize" use="optional"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcFaceBasedSurfaceModel
 SUBTYPE OF (IfcGeometricRepresentationItem);
  FbsmFaces : SET [1:?] OF IfcConnectedFaceSet;
 DERIVE
  Dim : IfcDimensionCount := 3;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

References  References: IfcSurfaceOrFaceSurface

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