# 8.12.3.44 IfcTextureMap

## 8.12.3.44.1 Semantic definition

An IfcTextureMap 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 surfaces of vertex based geometry models, such as

The IfcTextureMap has a list of TextureVertex, that corresponds to the points of the outer face bound of the vertex based geometry item. The corresponding pair of lists is:

1. the list of Polygon of the IfcFaceOuterBound of type IfcCartesianPoint, and
2. the list of Vertices of type IfcTextureVertex.

Each IfcTextureVertex (given as S, T coordinates of the 2-dimension texture coordinate system) corresponds to the geometric coordinates of the IfcCartesianPoint (given as 3-dimension X, Y, and Z coordinates within the object coordinate system of the geometric item).

Figure 8.12.3.44.A illustrates applying a texture map to a vertex based geometry.

Informal Propositions:

1. The IfcFace referenced in AppliedTo shall be used by the vertex based geometry, to which this texture map is assigned to by through the IfcStyledItem.

## 8.12.3.44.4 Formal representation

ENTITY IfcTextureMap
SUBTYPE OF (IfcTextureCoordinate);
Vertices : LIST [3:?] OF IfcTextureVertex;
MappedTo : IfcFace;
END_ENTITY;