For example, if you want to open nohab model with texture from game directories and game located at C:\Games\Train Fever\, command-line should looks like:
tfmv.exe “C:\Games\Train Fever\res\models\mesh\vehicle\train\nohab\nohab_lod_0_body.msh” “C:\Games\Train Fever\res\textures\models\vehicle\train\train_nohab.tga”
Also, now I working on GUI version.