**How to Use This Code:** **Verify Paths:** Double-check that the paths to `three.min.js`, `OrbitControls.js`, `OBJLoader.js`, and especially `assets/mesh.obj` are correct relative to where you save this HTML file. If you downloaded the libraries, make sure they are in a `js` subfolder. If the `mesh.obj` is in `assets`, ensure that folder exists at the same level as your HTML file. **Open the HTML file in your browser.** **Open the Developer Console (F12).** Look carefully at the messages in the "Console" tab. * You should see logs like "Initializing scene...", "Renderer created.", "Attempting to load OBJ model...". * If the model loads, you'll see "OBJ Model Loaded Successfully..." and "Model added to the scene.". * **If loading fails, you will see a red error message starting with "An error happened during OBJ loading:". This error message is key!** It might indicate a 404 Not Found (wrong path) or a problem parsing the file. * Also check the "Network" tab again to confirm if `mesh.obj` is listed and whether its status is 200 (OK) or 404 (Not Found).