IfcFaceBasedSurfaceModel

Item	Change	Description
IFC4 Addendum 2 Technical Corrigendum 1 4.0.2.1
IfcFaceBasedSurfaceModel	MODIFIED	Status changed to Deprecated.
IFC4x1 Final 4.1.0.0
IfcFaceBasedSurfaceModel	MODIFIED	Status 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:

The connected face sets shall not overlap or intersect except at common faces, edges or vertices.
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

#	Attribute	Type	Cardinality	Description	G
1	FbsmFaces	IfcConnectedFaceSet	S[1:?]	The set of connected face sets comprising the face based surface model.	X
	Dim :=3	IfcDimensionCount		The space dimensionality of this class, it is always 3.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @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
	StyledByItem	IfcStyledItem @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
1	FbsmFaces	IfcConnectedFaceSet	S[1:?]	The set of connected face sets comprising the face based surface model.	X
	Dim :=3	IfcDimensionCount		The 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;

 EXPRESS-G diagram

	Flächenmodell (basierend auf Einzelflächen)
	Face Based Surface Model