When working with 3D designs in AutoCAD, it's essential to have the ability to change the view to ensure you have the right perspective for your project. Here's how to do it:

1. Use the ViewCube: AutoCAD's ViewCube provides a simple and intuitive way to change your 3D view. Simply click and drag the cube to rotate your view in any direction.

2. Use the SteeringWheels: Another handy tool for changing your 3D view is the SteeringWheels feature. This allows you to easily pan, zoom, and orbit around your design to get the perfect angle.

3. Enter specific commands: If you need to change to a very specific view, you can use commands such as PLAN, SW Isometric, and SE Isometric to quickly switch your view.

4. Create and use viewports: Viewports allow you to split the screen and work with multiple views simultaneously. This can be helpful when comparing different perspectives of your 3D design.

5. Use the Navisworks software: If you have the Navisworks software, you can link your AutoCAD file to it and then use the Animator function to change the 3D view.

By mastering these techniques, you'll be able to easily change your 3D view in AutoCAD to ensure that you have the best perspective for your designs. This will help you to create accurate and visually appealing 3D models for any project.