IFC 4.3.1.0 (IFC4X3_ADD1)

8.8.3.23 IfcIndexedPolygonalFace

8.8.3.23.1 Semantic 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 directly, or via the PnIndex, if provided at IfcPolygonalFaceSet.

Figure 8.8.3.23.A shows an IfcIndexedPolygonalFace at an IfcPolygonalFaceSet not using PnIndex (the default).

IfcIndexedPolygonalFace not using PnIndex
Figure 8.8.3.23.A — Polygonal face geometry provided by indices into a point list

Figure 8.8.3.23.B shows an IfcIndexedPolygonalFace at an IfcPolygonalFaceSet using PnIndex.

IfcIndexedPolygonalFace using PnIndex
Figure 8.8.3.23.B — Polygonal face geometry provided by indices into an PN Index

8.8.3.23.2 Entity inheritance

8.8.3.23.3 Attributes

# Attribute Type Description
IfcRepresentationItem (2)
LayerAssignment SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems

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.

StyledByItem SET [0:1] OF IfcStyledItem FOR Item

Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.

Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes
IfcIndexedPolygonalFace (3)
1 CoordIndex LIST [3:?] OF IfcPositiveInteger

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.

ToFaceSet SET [1:?] OF IfcPolygonalFaceSet FOR Faces

Reference to the IfcPolygonalFaceSet for which this face is associated.

HasTexCoords SET [0:1] OF IfcTextureCoordinateIndices FOR TexCoordsOf

Optional reference to the IfcTextureCoordinateIndices that provide the texture coordinates for applying textures to this face.

Table 8.8.3.23.C

8.8.3.23.4 Formal representation

ENTITY IfcIndexedPolygonalFace
 SUPERTYPE OF (ONEOF
	(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;

8.8.3.23.5 References

8.8.3.23.6 Changelog

8.8.3.23.6.1 IFC4

  • New resource

8.8.3.23.6.2 IFC4.3_ADD1

  • inverse attribute, HasTexCoords