Material ID required for the various faces

[Esharc]

When parsing the .obj file the used material for the current face being parsed needs to be stored.

I need the index for the material being used for the face that is currently being parse, but I see that only the last used material is being stored in the Group of the data store.

In the copy of your library that I am using I added a MaterialIndex to the FaceVertex struct in the Face.cs file, and then in the FaceParser.cs file I added functionality to determine the index of the current material being used for the face.

This is an old project, so I assume most people that use this only have one colour in their .obj file. I have four.