Open MNM File
The MNM file extension is used to contain the names of a bipedal 3D character's markers along with their associated location.
It is basically used in Character Studio, which is part of the 3ds Max animation program.
Today the full name is Autodesk 3ds Max, formerly known as 3D Studio and 3D Studio Max, is a professional 3D computer graphics program for making 3D animations, models, games and images.
As the name implies, it is developed and produced by Autodesk Media and Entertainment.
The MNM file is considered a 3D image file, given its characteristics.