.MTL File Extension
File TypeOBJ Material Template Library File
What is an MTL file?
An MTL file is a material settings file used by 3D object editing applications, such as Adobe Photoshop and Autodesk Maya. It is stored alongside an .OBJ file and describes how a program should apply textures to that object. MTL files contain the names of the texture bitmap files to apply to an object as well as the 3D coordinates at which to apply them.
An OBJ file can reference more than one MTL file, and MTL files can reference more than one texture. In this way, users can easily apply multiple textures to the same object.
While MTL files are primarily used and generated by 3D object editing applications, they are saved in the plain text format, allowing users to open and edit them in most any text editor.
How do I open an MTL file?
Because MTL files are saved in plain text format, you can open an MTL file in any text editor, including:
NOTE: Because they are text files, you cannot open MTL files in 3D object editing applications such as Adobe Photoshop and Autodesk Maya (even though those applications create MTL files). These applications reference and apply settings from MTL files when you open a corresponding OBJ file.