Microsoft 3D Viewer is a built-in app in Windows 10 that allows users to view and manipulate 3D models. It supports various 3D file formats, including .obj, .stl, .ply, and .3mf. The app is designed for users to easily open, view, and interact with 3D models without the need for additional software. With Microsoft 3D Viewer, users can rotate, zoom, pan, and customize the appearance of 3D models. They can also take measurements and capture screenshots of the 3D models. This app is useful for anyone who needs to work with 3D models, whether for professional or personal use. It provides a user-friendly interface and basic tools for 3D modeling and rendering, making it accessible for beginners and advanced users alike.