IfcAdvancedFace

Semantic definitions at the entity

Entity definition

An advanced face is a specialization of a face surface that has to meet requirements on using particular topological and geometric representation items for the definition of the faces, edges and vertices.

An IfcAdvancedFace is restricted to:

have a face surface geometry of type IfcElementarySurface, IfcSweptSurface or IfcBSplineSurface,
have one IfcFaceOuterBound as the bound of the face, with the exception of closed surfaces,
have all faces to be bound by IfcEdgeLoop or IfcVertexLoop
have all edges to have an edge curve geometry
have the edge curve geometry restricted to IfcLine, IfcConic, IfcPolyline, or IfcBSplineCurve

NOTE Entity adapted from advanced_face defined in ISO 10303-511.

HISTORY New entity in IFC4

Formal Propositions

Rule	Description
ApplicableSurface	The geometry used in the definition of the face shall be restricted. The face geometry shall be an IfcElementarySurface, IfcSweptSurface, or IfcBSplineSurface.
RequiresEdgeCurve	The geometry of all bounding edges of the face shall be fully defined as IfcEdgeCurve's.
ApplicableEdgeCurves	The types of curve used to define the geometry of edges shall be restricted to IfcLine, IfcConic, IfcPolyline, or IfcBSplineCurve.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
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.	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.	X
IfcTopologicalRepresentationItem
IfcFace
1	Bounds	IfcFaceBound	S[1:?]	Boundaries of the face.	X
	HasTextureMaps	IfcTextureMap @MappedTo	S[0:?]		X
IfcFaceSurface
2	FaceSurface	IfcSurface	[1:1]	The surface which defines the internal shape of the face. This surface may be unbounded. The domain of the face is defined by this surface and the bounding loops in the inherited attribute SELF\FaceBounds.	X
3	SameSense	IfcBoolean	[1:1]	This flag indicates whether the sense of the surface normal agrees with (TRUE), or opposes (FALSE), the sense of the topological normal to the face.	X
IfcAdvancedFace

Formal representations

XSD Specification

 <xs:element name="IfcAdvancedFace" type="ifc:IfcAdvancedFace" substitutionGroup="ifc:IfcFaceSurface" nillable="true"/>

 <xs:complexType name="IfcAdvancedFace">

  <xs:complexContent>

   <xs:extension base="ifc:IfcFaceSurface"/>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcAdvancedFace

 SUBTYPE OF (IfcFaceSurface);

 WHERE

  ApplicableSurface : SIZEOF (
['IFCGEOMETRYRESOURCE.IFCELEMENTARYSURFACE',
 'IFCGEOMETRYRESOURCE.IFCSWEPTSURFACE',
 'IFCGEOMETRYRESOURCE.IFCBSPLINESURFACE'] *
TYPEOF(SELF\IfcFaceSurface.FaceSurface)) = 1;
  RequiresEdgeCurve : SIZEOF(QUERY (ElpFbnds <* 
  QUERY (Bnds <* SELF\IfcFace.Bounds |
    'IFCTOPOLOGYRESOURCE.IFCEDGELOOP' IN TYPEOF(Bnds.Bound)) |
     NOT (SIZEOF (QUERY (Oe <* ElpFbnds.Bound\IfcEdgeLoop.EdgeList |
       NOT('IFCTOPOLOGYRESOURCE.IFCEDGECURVE' IN 
       TYPEOF(Oe\IfcOrientedEdge.EdgeElement)
  ))) = 0
))) = 0;
  ApplicableEdgeCurves : SIZEOF(QUERY (ElpFbnds <* 
  QUERY (Bnds <* SELF\IfcFace.Bounds |
    'IFCTOPOLOGYRESOURCE.IFCEDGELOOP' IN TYPEOF(Bnds.Bound)) |
     NOT (SIZEOF (QUERY (Oe <* ElpFbnds.Bound\IfcEdgeLoop.EdgeList |
       NOT (SIZEOF (['IFCGEOMETRYRESOURCE.IFCLINE',
                     'IFCGEOMETRYRESOURCE.IFCCONIC',
                     'IFCGEOMETRYRESOURCE.IFCPOLYLINE',
                     'IFCGEOMETRYRESOURCE.IFCBSPLINECURVE'] *
         TYPEOF(Oe\IfcOrientedEdge.EdgeElement\IfcEdgeCurve.EdgeGeometry)) = 1 )
  )) = 0
))) = 0;
END_ENTITY;

 EXPRESS-G diagram

Item	Change	Description
IFC2x3 to IFC4
IfcAdvancedFace	ADDED
IFC4 Addendum 1
IfcAdvancedFace
SameSense	MODIFIED	Type changed from BOOLEAN to IfcBoolean.

	Fläche - komplex
	Advanced Face
	Face avancée