IfcVertexBasedTextureMap

Definition from IAI: An IfcVertexBasedTextureMap provides the mapping of the 2-dimensional texture coordinates (S, T) to the vertices of a single surface onto which it is mapped. For each vertex coordinates, provided by IfcCartesianPoin, a set of 2 (S, T) texture coordinates are given.

The IfcVertexBasedTextureMap provides two corresponding lists:

1. a list of TexturePoints, given by min. of 3 IfcCartesianPoint's.
2. a list of TextureVertices, given by min. of 3 IfcTextureVertex's.

These corresponding lists are:

> `TextureVertices``-- LIST [3:?] --o IfcTextureVertex -- LIST [2:2] --o IfcParameterValue
> ` `TexturePoints -- LIST [3:?] --o IfcCartesianPoint -- LIST [3:3] --o IfcLengthMeasure
> ` ``

Each texture vertex (given as S, T coordinates of 2 dimension) corresponds to the geometric coordinates (given as X, Y, and Z coordinates of 3 dimensions) of the Cartesian point, All Cartesian points within the list of shall lie within a plane.

> NOTE The application needs to ensure that the number of vertex points are identical with the number of texture vertex coordinates and that both lists correlate.

> HISTORY New class in IFC Release 2x Edition 2.
> IFC2x Edition 3 CHANGE The IfcVertexBasedTextureMap has changed by deleting the attribute VertexBasedGeometries. The attribute TexturePoints has been added.

Informal propositions:

1. The list of TextureVertices shall correspond to the list of TexturePoints.
2. All Cartesian points of the list of TexturePoints shall lie in one plane
3. The references points shall be part of the vertex based geometry to which the annotation surface with textures is assigned.

EXPRESS specification:

ENTITY IfcVertexBasedTextureMap;
TextureVertices | : | LIST [3:?] OF IfcTextureVertex;
TexturePoints | : | LIST [3:?] OF IfcCartesianPoint;
END_ENTITY;

Attribute definitions:

TextureVertices | : | List of texture vertex coordinates, each texture vertex refers to the Cartesian point within the polyloop (corresponding lists). The first coordinate[1] is the S, the second coordinate[2] is the T parameter value.
TexturePoints | : | Reference to a list of polyloop's defining a face bound of a face within a vertex based geometry.

Inheritance graph

ENTITY IfcVertexBasedTextureMap;
ENTITY IfcVertexBasedTextureMap;
TextureVertices | : | LIST [3:?] OF IfcTextureVertex;
TexturePoints | : | LIST [3:?] OF IfcCartesianPoint;
END_ENTITY;