So, you've just received an OBJ file and you're wondering how to open it on your Mac. OBJ files are commonly used for 3D modeling and are compatible with various software applications. Here's how you can open OBJ files on your Mac:

1. Use 3D Modeling Software: If you're looking to view and edit the content of the OBJ file, you can use 3D modeling software such as Blender, SketchUp, or Autodesk Maya. These applications allow you to import and manipulate OBJ files for 3D design purposes.

2. Use 3D Printing Software: If you're planning to 3D print the content of the OBJ file, you can use 3D printing software such as Cura or Simplify3D. These programs enable you to import OBJ files and prepare them for 3D printing on your Mac.

3. Use Viewer Applications: If you simply want to view the contents of the OBJ file without editing or printing, you can use 3D viewer applications such as MeshLab or Adobe Dimension. These tools allow you to visualize the OBJ file's 3D model on your Mac.

4. Use Online Converters: If you prefer a quick and easy solution, you can use online file converters to convert the OBJ file to a more commonly supported format such as STL. Once converted, you can open the file using various 3D modeling and printing software on your Mac.

5. Use Native Applications: Fortunately, macOS comes with some built-in applications that can open OBJ files. Preview, for example, can display OBJ files and allows you to rotate and view the 3D model. Quick Look also provides a quick way to preview the content of the OBJ file without needing to open a specific application.

By following these methods, you can easily open and work with OBJ files on your Mac for 3D modeling and 3D printing purposes. Whether you're a designer, engineer, or hobbyist, these options provide you with the flexibility to access and utilize OBJ files seamlessly on your Mac computer.