IfcIndexedTriangleTextureMap

BACnet MVD

#### IfcIndexedTriangleTextureMap

Natural language names

| Liste von Indizes für Texturen auf Dreiecken
| Indexed Triangle Texture Map

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcIndexedTriangleTextureMap |  |  | ADDED |
IFC4 Addendum 1
IfcIndexedTriangleTextureMap |  |  |  |
TexCoordIndex |  |  | MODIFIED | Type changed from INTEGER to IfcPositiveInteger.

##### Semantic definitions at the entity

Entity definition

The IfcIndexedTriangleTextureMap provides the mapping of the 2-dimensional texture coordinates to the surface onto which it is mapped. It is used for mapping the texture to triangles of the IfcTriangulatedFaceSet.

The IfcIndexedTriangleTextureMap defines an index into an indexed list of texture coordinates. The TexCoordIndex is a two-dimensional list, where

- first dimension is the unbounded list of faces corresponding to the list of triangles defined by CoordIndex at IfcTriangulatedFaceSet;
- second dimension is the fixed list of three indices to texture vertices cooresponding to the fixed list of indices to vertices at IfcTriangulatedFaceSet

The TexCoords defined at supertype IfcIndexedTextureMap are a two-dimensional list of texture coordinates provided by two parameter values. Each index of the second dimension list of TexCoordIndex points to a texture vertex in TexCoords.

Figure 341 shows the use of IfcTriangulatedFaceSet with textures.

Figure 341 — Indexed triangle texture map |

Figure 342 illustrates an IfcTriangulatedFaceSet represented by
IfcTriangulatedFaceSet.CoordIndex: ((1,6,5), (1,2,6), (6,2,7), (7,2,3), (7,8,6), (6,8,5), (5,8,1), (1,8,4), (4,2,1), (2,4,3), (4,8,7), (7,3,4))
IfcCartesianPointList.CoordList: ((0.,0.,0.), (1.,0.,0.), (1.,1.,0.), (0.,1.,0.), (0.,0.,2.), (1.,0.,2.), (1.,1.,2.), (0.,1.,2.))
IfcIndexedTriangleTextureMap.TexCoordsIndex: ((1 4 3), (1 2 4), (3 1 4), (4 1 2), (8 7 6), (6 7 5), (4 3 2), (2 3 1), (5 8 7), (8 5 6), (2 4 3), (3 1 2))
IfcTextureVertexList.TexCoordsList: ((0. -0.5), (1. -0.5), (0. 1.5), (1. 1.5), (0. 0.), (0. 1.), (1. 0.), (1. 1.))

Figure 342 — Indexed triangle texture map geometry |

> HISTORY New entity in IFC4.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
4 | TexCoordIndex | IfcPositiveInteger | ? L[1:?] L[3:3] | Index into the IfcTextureVertexList for each vertex of the triangles representing the IfcTriangulatedFaceSet. | X | X

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcPresentationItem
IfcTextureCoordinate
1 | Maps | IfcSurfaceTexture | L[1:?] | Reference to the one (or many in case of multi textures with identity transformation to geometric surfaces) subtype(s) of IfcSurfaceTexture that are mapped to a geometric surface by the texture coordinate transformation. | X | X
IfcIndexedTextureMap
2 | MappedTo | IfcTessellatedFaceSet |  | Reference to the IfcTessellatedFaceSet to which it applies the texture map. | X | X
3 | TexCoords | IfcTextureVertexList |  | Indexable list of texture vertices. | X | X
IfcIndexedTriangleTextureMap
4 | TexCoordIndex | IfcPositiveInteger | ? L[1:?] L[3:3] | Index into the IfcTextureVertexList for each vertex of the triangles representing the IfcTriangulatedFaceSet. | X | X

##### Formal representations

XML Specification
`<xs:element name="IfcIndexedTriangleTextureMap" type="ifc:IfcIndexedTriangleTextureMap" substitutionGroup="ifc:IfcIndexedTextureMap" nillable="true"/>
<xs:complexType name="IfcIndexedTriangleTextureMap">
<xs:complexContent>
<xs:extension base="ifc:IfcIndexedTextureMap">
<xs:attribute name="TexCoordIndex" 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 IfcIndexedTriangleTextureMap
SUBTYPE OF (IfcIndexedTextureMap);
TexCoordIndex : OPTIONAL LIST [1:?] OF LIST [3:3] OF IfcPositiveInteger;
END_ENTITY;

EXPRESS-G diagram

`

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