IFC 4.3.0.1 (IFC4X3_TC1)

8.12.3.45 IfcTextureVertex

8.12.3.45.1 Semantic definition

An IfcTextureVertex is a list of 2 (S, T) texture coordinates.

Each vertex-based geometry node uses a set of 2D texture coordinates that map textures to vertices. Texture map values ( ImageTexture, PixelTexture) range from [0.0, 1.0] along the S-axis and T-axis. However, texture coordinate values may be in the range (-∞,∞). Texture coordinates identify a location (and thus a colour value) in the texture map. The horizontal coordinate S is specified first, followed by the vertical coordinate T. If the texture map is repeated in a given direction (S-axis or T-axis), a texture coordinate C (s or t) is mapped into a texture map that has N pixels in the given direction as follows:

Texture map location = (C - floor(C)) × N

If the texture map is not repeated, the texture coordinates are clamped to the 0.0 to 1.0 range as follows:

Texture map location = N,     if C > 1.0,

= 0.0, if C < 0.0,
= C × N, if 0.0 ≤ C ≤ 1.0.

8.12.3.45.2 Entity inheritance

8.12.3.45.3 Attributes

# Attribute Type Description
IfcTextureVertex (1)
1 Coordinates LIST [2:2] OF IfcParameterValue

The first Coordinate[1] is the S, the second Coordinate[2] is the T parameter value.

Table 8.12.3.45.A

8.12.3.45.4 Formal representation

ENTITY IfcTextureVertex
 SUBTYPE OF (IfcPresentationItem);
	Coordinates : LIST [2:2] OF IfcParameterValue;
END_ENTITY;

8.12.3.45.5 References