The 3D Viewer app in Windows 10 allows users to view and interact with 3D models and images in various file formats. Whether you're a designer, artist, or just want to explore 3D objects, the 3D Viewer app provides a simple and intuitive way to do so. Here's how to use the 3D Viewer in Windows 10:

1. Open a 3D model or image file in the 3D Viewer app by right-clicking the file and selecting 'Open with' > '3D Viewer.'

2. Once the file is opened, you can use your mouse or touch screen to rotate, zoom, and pan around the 3D model or image. This allows you to explore the object from different angles and perspectives.

3. The 3D Viewer app also provides tools for measuring distances and areas within a 3D model. This can be useful for designers and architects who need to take accurate measurements of their models.

4. In addition to viewing 3D objects, the 3D Viewer app allows users to annotate and mark up their models with comments and annotations. This can be helpful for collaboration and communication when working on 3D projects.

5. The app supports a variety of 3D file formats, including .obj, .fbx, .3mf, and .stl, among others. This means you can open and view models created in different 3D design software and tools.

6. If you have a mixed reality headset, such as the HoloLens or other VR devices, you can also use the 3D Viewer app to view 3D models in virtual reality. This provides an immersive experience and allows for a more realistic exploration of 3D objects.

Overall, the 3D Viewer app in Windows 10 is a versatile tool for viewing and interacting with 3D models and images. Whether you're a professional designer or simply curious about 3D objects, the app provides a user-friendly way to explore and work with 3D content. Give it a try and see how it can enhance your experience with 3D visuals on your Windows 10 device.