6.1.2.1 Assigning Texture Coordinates

A common question is how texture coordinates are assigned to the vertices of an object. There is no single answer. Sometimes the texture coordinates are some mathematical function of the object coordinates. In other cases, the texture coordinates are manually assigned by the artist that created a given 3D model. Most common 3D object file formats such as VRML or the Wavefront OBJ format contain accompanying texture coordinates. Keep in mind that the assignment of texture coordinates for a particular 3D model is not something that can be done independent of the intended texture to be mapped onto the object.