AutoCAD is a powerful CAD software that is widely used for creating 2D and 3D designs across various industries. Viewing 3D models in AutoCAD is an essential part of the design process, allowing engineers and designers to visualize their projects from different perspectives. Here are some tips for effectively viewing 3D in AutoCAD:

1. Navigate in 3D space: AutoCAD offers several tools for navigating in 3D space, such as the 3DORBIT command, which allows you to rotate the view around the 3D model. You can also use the 3D Navigation cube to easily switch between standard views.

2. Use visual styles: AutoCAD provides different visual styles to help you view 3D models more effectively. The default visual style is usually set to 2D wireframe, but you can switch to realistic, conceptual, or shaded visual styles to get a better sense of the 3D geometry.

3. Adjust perspective: When working with 3D models, you can set the perspective mode to get a more realistic view of the design. The DVIEW command allows you to adjust the perspective parameters and create lifelike renderings of your 3D models.

4. Section and slice: AutoCAD's sectioning tools enable you to cut through 3D models to visualize their internal structures. You can use the SECTIONPLANE command to create a section plane and then use the SECTION command to generate 2D cross sections.

5. Create and manage views: AutoCAD allows you to create and save custom views of your 3D models. This is particularly useful when working on complex designs with multiple viewpoints. You can save, restore, and delete views using the VIEW and VPORTS commands.

6. Utilize 3D modeling tools: AutoCAD offers a wide range of 3D modeling tools to help you create and edit 3D geometry. Familiarize yourself with commands such as EXTRUDE, REVOLVE, and SWEEP to generate 3D objects and enhance your design.

By mastering these techniques, you can improve your ability to view and work with 3D models in AutoCAD, ultimately leading to more efficient and accurate engineering designs.