IfcIndexedPolygonalFace

Natural language names
Indexed Polygonal Face
Change log
ItemSPFXMLChangeDescription
IFC4 Addendum 2 4.0.2.0
    IfcIndexedPolygonalFaceADDED
IFC4 Addendum 2 4.0.2.0
    IfcIndexedPolygonalFaceADDED
Semantic definitions at the entity
Entity definition

The IfcIndexedPolygonalFace is a compact representation of a planar face being part of a face set. The vertices of the polygonal planar face are provided by 3 or more Cartesian points, defined by indices that point into an IfcCartesianPointList3D, either direcly, or via the PnIndex, if provided at IfcPolygonalFaceSet.

Figure 330 shows an IfcIndexedPolygonalFace at an IfcPolygonalFaceSet not using PnIndex (the default).

"IfcIndexedPolygonalFace"

Figure 330 — Polygonal face geometry provided by indices into a point list

 

Figure 331 shows an IfcIndexedPolygonalFace at an IfcPolygonalFaceSet using PnIndex.

"IfcIndexedPolygonalFace us
ing PnIndex"

Figure 331 — Polygonal face geometry provided by indices into a point list

HISTORY  New entity in IFC4 Addendum 2.

Attribute definitions
#AttributeTypeCardinalityDescription G
1CoordIndexIfcPositiveIntegerL[3:?] One-dimensional list with the indices for the three or more points, that define the vertices of the outer loop. If the tessellated face set is closed, indicated by SELF\IfcTessellatedFaceSet.Closed, then the points, defining the outer loop, shall connect counter clockwise, as seen from the outside of the body, so that the resulting normal will point outwards.
NOTE  The coordinates of the vertices are provided by the indexed list of SELF\IfcTessellatedFaceSet.Coordinates.CoordList. If the SELF\IfcTessellatedFaceSet.PnIndex is provided, the indices point into it, otherwise directly into the IfcCartesianPointList3D.
X
ToFaceSetIfcPolygonalFaceSet
@Faces
S[1:?]Reference to the IfcPolygonalFaceSet for which this face is associated. X
Inherited definitions from supertypes
Entity inheritance IfcIndexedPolygonalFaceWithVoids IfcTessellatedItem 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
IfcTessellatedItem
IfcIndexedPolygonalFace
1CoordIndexIfcPositiveIntegerL[3:?] One-dimensional list with the indices for the three or more points, that define the vertices of the outer loop. If the tessellated face set is closed, indicated by SELF\IfcTessellatedFaceSet.Closed, then the points, defining the outer loop, shall connect counter clockwise, as seen from the outside of the body, so that the resulting normal will point outwards.
NOTE  The coordinates of the vertices are provided by the indexed list of SELF\IfcTessellatedFaceSet.Coordinates.CoordList. If the SELF\IfcTessellatedFaceSet.PnIndex is provided, the indices point into it, otherwise directly into the IfcCartesianPointList3D.
X
ToFaceSetIfcPolygonalFaceSet
@Faces
S[1:?]Reference to the IfcPolygonalFaceSet for which this face is associated. X
Formal representations
XML Specification
 <xs:element name="IfcIndexedPolygonalFace" type="ifc:IfcIndexedPolygonalFace" substitutionGroup="ifc:IfcTessellatedItem" nillable="true"/>
 <xs:complexType name="IfcIndexedPolygonalFace">
  <xs:complexContent>
   <xs:extension base="ifc:IfcTessellatedItem">
    <xs:attribute name="CoordIndex" use="optional">
     <xs:simpleType>
      <xs:restriction>
       <xs:simpleType>
        <xs:list itemType="ifc:IfcPositiveInteger"/>
       </xs:simpleType>
       <xs:minLength value="3"/>
      </xs:restriction>
     </xs:simpleType>
    </xs:attribute>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcIndexedPolygonalFace
 SUPERTYPE OF(IfcIndexedPolygonalFaceWithVoids)
 SUBTYPE OF (IfcTessellatedItem);
  CoordIndex : LIST [3:?] OF IfcPositiveInteger;
 INVERSE
  ToFaceSet : SET [1:?] OF IfcPolygonalFaceSet FOR Faces;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

References  References: IfcPolygonalFaceSet

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