The mesh class keeps a pointer to a list of texture vertices in addition to its regular vertices which are allocated on a per-need basis. For example if mapping coordinates are assigned to the mesh then these extra vertices are allocated. These vertices are completely independent of the regular vertices in the mesh.

In addition to the texture vertices there are also texture faces. There needs to be one texture face for every regular face in the mesh. Each texture face has three indices into the texture vertex array. This allows every face of the mesh to have its own mapping.