IFC (IFC4X3_ADD2) under development IfcTextureMap 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).

IfcTextureMap_fig-1.png 35,6 KB
Figure — Texture map

Figure 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. Entity inheritance Attributes

# Attribute Type Description
IfcTextureCoordinate (1)
1 Maps LIST [1:?] OF IfcSurfaceTexture

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.

Click to show 1 hidden inherited attributes Click to hide 1 inherited attributes
IfcTextureMap (2)
2 Vertices LIST [3:?] OF IfcTextureVertex

List of texture coordinate vertices that are applied to the corresponding points of the polyloop defining a face bound.

3 MappedTo IfcFace

The face that defines the corresponding list of points along the bounding poly loop of the face outer bound.

Table Formal representation

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

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Is this page difficult to understand? Let us know! Changelog IFC4

  • attribute, MappedTo
  • where rule, WR11
  • attribute TextureMaps name, Changed from "TextureMaps" to "Vertices"
  • attribute TextureMaps type, Changed from "set[1:?] of IfcVertexBasedTextureMap" to "list[3:?] of IfcTextureVertex"