IfcIndexedPolygonalFace

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

Figure 483 — Polygonal face geometry provided by indices into a point list

Figure 484 shows an IfcIndexedPolygonalFace at an IfcPolygonalFaceSet using PnIndex.

"IfcIndexedPolygonalFace us
ing PnIndex"

Figure 484 — Polygonal face geometry provided by indices into a point list

HISTORY New entity in IFC4 Addendum 2.

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
1	CoordIndex	IfcPositiveInteger	L[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
	ToFaceSet	IfcPolygonalFaceSet @Faces	S[1:?]	Reference to the IfcPolygonalFaceSet for which this face is associated.	X
	HasTexCoords	IfcTextureCoordinateIndices @TexCoordsOf	S[0:1]		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
IfcTessellatedItem
	HasColours	IfcIndexedColourMap @MappedTo	S[0:1]	Reference to the indexed colour map providing the corresponding colour RGB values to the faces of the subtypes of IfcTessellatedFaceSet.	X
IfcIndexedPolygonalFace
1	CoordIndex	IfcPositiveInteger	L[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
	ToFaceSet	IfcPolygonalFaceSet @Faces	S[1:?]	Reference to the IfcPolygonalFaceSet for which this face is associated.	X
	HasTexCoords	IfcTextureCoordinateIndices @TexCoordsOf	S[0:1]		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;

  HasTexCoords : SET [0:1] OF IfcTextureCoordinateIndices FOR TexCoordsOf;

END_ENTITY;

 EXPRESS-G diagram

Item	SPF	XML	Change	Description
IFC4 Addendum 2 4.0.2.0
IfcIndexedPolygonalFace			ADDED
IFC4X3_ADD2 to IFC4X4_draft
IfcIndexedPolygonalFace
HasColours			ADDED