There is no one all singing, all dancing; file format that will do everything you are expecting it to. You are expecting more out of FBX than it is capable of. Same with MTL. This is an old file format. It doesn't support a lot of more modern information. I really suggest that you fully investigate file formats first and see just what each actually does instead of blindly expecting results from whatever one you seem to play with at any given time. Just read the file specs before you blindly expect results. People are trying to help you; but you aren't accepting the answers you are given. That or we are not properly understanding your questions due to an inability to express the info as we require it in order to help. Check out the file specs and maybe you will be better able to explain just what it is you want. Ka vs. Illum as an example.