: While an .obj file defines the 3D geometry (vertices and surfaces), the .mtl file describes how those surfaces appear. Without it, a model may appear as a simple, untextured gray or white mesh.
is an archived file containing material data for 3D digital assets. The .mtl (Material Library) file format is a standard companion to .obj files, used to define the visual properties of a 3D model, such as surface colors, textures, and reflection maps. Technical Overview MegaOne MTL.7z
To utilize the materials within this archive, follow these standard workflows: : While an
: Drag both the .obj and .mtl files into the Unity Project panel simultaneously to automatically apply materials. such as surface colors