added |

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

IfcIndexedPolygonalFace"' src="../figures/ifcindexedpolygonalface_01.png" title="Figure 1 — Polygonal face geometry provided by indices into a point list"/>

Figure 2 shows an *IfcIndexedPolygonalFace* at an *IfcPolygonalFaceSet* using *PnIndex*.

IfcIndexedPolygonalFace us ing PnIndex"' src="../figures/ifcindexedpolygonalface_02.png" title="Figure 2 — Polygonal face geometry provided by indices into a point list"/>

HISTORY New entity in IFC4 Addendum 2.

# | Attribute | Type | Description |
---|---|---|---|

IfcRepresentationItem | |||

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. > 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. | |

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. > IFC2x3 CHANGE The inverse attribute StyledByItem has been added. | |

IfcGeometricRepresentationItem | |||

IfcTessellatedItem | |||

IfcIndexedPolygonalFace | |||

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. > 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. |

ToFaceSet | SET [1:?] OF IfcPolygonalFaceSet FOR Faces | Reference to the IfcPolygonalFaceSet for which this face is associated. |

ENTITY IfcIndexedPolygonalFace SUPERTYPE OF (ONEOF (IfcIndexedPolygonalFaceWithVoids)) SUBTYPE OF (IfcTessellatedItem); CoordIndex : LIST [3:?] OF IfcPositiveInteger; INVERSE ToFaceSet : SET [1:?] OF IfcPolygonalFaceSet FOR Faces; END_ENTITY;