IFC 4.3.x development

8.12.3.40 IfcTextureCoordinateGenerator

Change log

IFC4

modificationsattributes Parameter definition Changed from list[1:?] of IfcSimpleValue to list[1:?] of IfcReal
modificationsattributes Parameter is_optionalChanged from False to True

8.12.3.40.1 Semantic definitions at the entity

The IfcTextureCoordinateGenerator describes a procedurally defined mapping function with input parameter to map 2D texture coordinates to 3D geometry vertices. The allowable Mode values and input Parameter need to be agreed upon in view definitions and implementer agreements.

NOTE  It is recommended to use the texture coordinate generation modes as defined in X3D.

NOTE  Definition according to ISO/IEC 19775-1:

The TextureCoordinateGenerator supports the automatic generation of texture coordinates for geometric shapes.
The mode field describes the algorithm used to compute texture coordinates. * SPHERE, * CAMERASPACENORMAL, * CAMERASPACEPOSITION, * CAMERASPACEREFLECTIONVECTOR, * SPHERE-LOCAL, * COORD, * COORD-EYE, * NOISE, * NOISE-EYE, * SPHERE-REFLECT, * SPHERE-REFLECT-LOCAL

NOTE  The definitions of texturing within this standard have been developed in dependence on the texture component of X3D. See ISO/IEC 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1, 18 Texturing component for the definitions in the international standard.

HISTORY  New entity in IFC2x2.

IFC2x2 Add2 CHANGE  The attribute Texture has been deleted.

8.12.3.40.1 Attributes

#Attribute Type Description
IfcPresentationItem
IfcTextureCoordinate
1Maps LIST [1:?] OF IfcSurfaceTextureReference 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.
IfcTextureCoordinateGenerator
2Mode IfcLabel The Mode attribute describes the algorithm used to compute texture coordinates.

> NOTE  The applicable values for the Mode attribute are determined by view definitions or implementer agreements. It is recommended to use the modes described in ISO/IES 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1. See [18.4.8 TextureCoordinateGenerator](http://www.web3d.org/x3d/specifications/ISO-IEC-19775-1.2-X3D-AbstractSpecification/Part01/components/texturing.html#TextureCoordinateGenerator) for recommended values.
3Parameter OPTIONAL LIST [1:?] OF IfcReal The parameters used as arguments by the function as specified by Mode.

> IFC4 CHANGE : Data type restricted to REAL.

8.12.3.40.2 Entity inheritance

dot_inheritance IfcTextureCoordinateGenerator IfcTextureCoordinateGenerator IfcTextureCoordinate IfcTextureCoordinate IfcTextureCoordinateGenerator->IfcTextureCoordinate IfcIndexedTextureMap IfcIndexedTextureMap IfcIndexedTextureMap->IfcTextureCoordinate IfcPresentationItem IfcPresentationItem IfcTextureCoordinate->IfcPresentationItem IfcTextureMap IfcTextureMap IfcTextureMap->IfcTextureCoordinate IfcPresentationItem_children 16 more... IfcPresentationItem_children->IfcPresentationItem

8.12.3.40.3 Formal representations

ENTITY IfcTextureCoordinateGenerator
 SUBTYPE OF (IfcTextureCoordinate);
	Mode : IfcLabel;
	Parameter : OPTIONAL LIST [1:?] OF IfcReal;
END_ENTITY;