When working on 3D designs in AutoCAD, changing the view is essential to ensure you have the best perspective for your project. Here's how you can easily change the 3D view in AutoCAD:

1. Using the ViewCube: AutoCAD's ViewCube is a great tool for changing the 3D view. Simply click and drag the ViewCube to rotate your view in any direction. You can also click on the different faces of the ViewCube to quickly change to a top, bottom, front, back, left, or right view.

2. Using the Navigation Bar: The Navigation Bar in AutoCAD provides easy access to various 3D navigation tools. You can use the Orbit tool to freely rotate the view, the Zoom tool to change the zoom level, and the Pan tool to move the view around.

3. Using the Viewpoint Presets: AutoCAD offers several pre-defined viewpoint presets that you can use to quickly change the 3D view. Simply select the desired viewpoint from the list to instantly change your perspective.

4. Using the DVIEW Command: The DVIEW command in AutoCAD allows you to create a custom 3D view by specifying the viewing direction and angle. This gives you full control over the perspective of your design.

5. Customizing the User Interface: You can also customize the AutoCAD user interface to add quick access to your most frequently used 3D view commands. This can help streamline your workflow and make it easier to change the 3D view as needed.

By mastering these techniques, you can easily change the 3D view in AutoCAD to get the best perspective for your designs. Whether you're working on architectural models, mechanical parts, or any other 3D project, having the right view can make a big difference in understanding and presenting your work.