IfcIndexedPolygonalFace

BACnet MVD

#### IfcIndexedPolygonalFace

Natural language names

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC4 Addendum 2
IfcIndexedPolygonalFace |  |  | ADDED |

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

Figure 286 — Polygonal face geometry provided by indices into a point list

Figure 287 shows an IfcIndexedPolygonalFace at an IfcPolygonalFaceSet using PnIndex.

Figure 287 — Polygonal face geometry provided by indices into a point list

> HISTORY New entity in IFC4 Addendum 2.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---

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

X

| ToFaceSet | IfcPolygonalFaceSet @Faces | S[1:?] | Reference to the IfcPolygonalFaceSet for which this face is associated. |  | X

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
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

X

IfcGeometricRepresentationItem
IfcTessellatedItem
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

X

| ToFaceSet | IfcPolygonalFaceSet @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;

EXPRESS-G diagram

`

References: IfcPolygonalFaceSet

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