Are you a web developer looking to inspect and manipulate 3D web content? Firefox Developer Tools provides a 3D View feature that allows you to view the structure of a web page in a three-dimensional space. Here's how you can open and use the 3D View in Firefox:

1. Open Firefox Browser: Launch the Firefox browser on your computer.

2. Navigate to a Web Page: Enter the URL of the web page you want to inspect in the address bar and press Enter.

3. Access Developer Tools: Right-click anywhere on the web page and select 'Inspect Element' from the context menu. Alternatively, you can use the keyboard shortcut Ctrl+Shift+I (Cmd+Option+I on Mac) to open Developer Tools.

4. Navigate to 3D View: In the Developer Tools panel, look for the '3D View' tab and click on it to open the 3D View interface.

5. Explore the 3D View: Once the 3D View is open, you can interact with the three-dimensional representation of the web page. You can rotate, pan, and zoom to get a better understanding of the page's structure and layout in 3D space.

6. Inspect and Manipulate Elements: Use the 3D View to inspect individual elements on the web page. By clicking on an element in the 3D space, you can see its corresponding code in the HTML panel and make modifications as needed.

7. Utilize 3D View Features: The 3D View also provides additional features such as wireframe and model views, as well as the ability to highlight elements in the scene.

8. Close 3D View: Once you have finished using the 3D View, you can close it by clicking on the 'X' icon in the tab or by switching to a different tab in the Developer Tools panel.

By following these steps, you can open and leverage the 3D View feature in Firefox Developer Tools to inspect and manipulate 3D web content. Whether you're debugging a website, optimizing performance, or experimenting with 3D design, the 3D View can be a valuable tool in your web development workflow.