Photoshop is not just for 2D design—it also has powerful capabilities for 3D modeling. One of the most common file types for 3D models is the .obj file, and you can create these directly in Photoshop. Here's how.

1. Open Photoshop: Launch Photoshop and create a new document or open an existing one where you want to create the 3D model.

2. Switch to 3D Workspace: In the top menu, go to 'Window' > 'Workspace' > '3D'. This will change the Photoshop workspace to focus on 3D modeling.

3. Create 3D Object: In the 3D workspace, go to the top menu and select '3D' > 'New 3D Layer' > 'Mesh from Grayscale' or 'Mesh from Depth Map'. You can also import existing 3D models if you have them.

4. Edit 3D Model: Once the 3D model is created, you can use the various tools in Photoshop to edit and manipulate the model. This includes tools for rotating, scaling, and moving the model in 3D space.

5. Export as Obj File: After you have finished editing the 3D model, go to 'File' > 'Export' > 'Export 3D Layer'. In the export settings, choose 'Wavefront OBJ' as the file format and set other export options as needed. Then click 'OK' to export the 3D model as an .obj file.

By following these steps, you can create .obj files directly in Photoshop, allowing you to seamlessly integrate your 3D modeling work with your 2D design projects. This opens up a world of possibilities for creating visually stunning and innovative designs.