When importing an .obj file into Unity you need to drag both the .obj and also the .mtl file into the project view at the same time in order to preserve the texture assignments. My question is once the importing is complete may I safely delete the .mtl files from the project view? They don’t seem to have any function after the import is done as far as I can tell, but I would feel more confident if I had some verification.
It’s not really critical to delete them but it would help in keeping things neat and tidy in the project view.