If you are working on a 3D modeling project in Unity, you might want to enhance the visual quality of your 3D models by applying MTL (Material Template Library) on OBJ (3D object). Here's a step-by-step guide on how to do it:

1. Import your OBJ model into Unity: Start by importing your OBJ model into the Unity project. Simply drag and drop the OBJ file into the Assets folder of your project to import it.

2. Import the MTL file: If your OBJ file is accompanied by an MTL file, you will need to import it into Unity as well. Similarly, drag and drop the MTL file into the Assets folder to import it.

3. Apply the MTL to the OBJ: Select your OBJ model in the Assets folder, then in the Inspector window, you will see the Mesh Renderer component. Expand the Materials section and click on the small circle icon to create a new material. You can then assign the imported MTL file to this material.

4. Tweak the material properties: After applying the MTL file to the OBJ model, you can further tweak the material properties such as color, metallicness, smoothness, and other parameters to achieve the desired visual effect.

5. Fine-tune the lighting: To complement the MTL-applied OBJ model, you may need to fine-tune the lighting in your Unity scene to showcase the material's characteristics properly. Experiment with different light sources and settings to find the perfect balance.

6. Test in different environments: Once you have applied the MTL on the OBJ and adjusted the lighting, it's a good practice to test your model in different environments and conditions to ensure that it looks good from all angles.

By following these steps, you can effectively put MTL on OBJ in Unity and elevate the visual quality of your 3D models. Whether you are working on a game, simulation, or visualization project, understanding how to apply MTL to OBJ will be a valuable skill in your Unity development journey.