Opening OBJ files in Ubuntu is a common task for those working with 3D models. Whether you're a designer, architect, or hobbyist, it's essential to be able to easily access and view OBJ files on your Ubuntu system. Fortunately, there are multiple ways to accomplish this. Here's a guide to help you get started:

Using the GUI Method:

1. Open your file manager in Ubuntu.

2. Navigate to the directory where your OBJ file is located.

3. Right-click on the OBJ file and select 'Open With Other Application.'

4. Choose your preferred 3D modeling software or viewer from the list of available applications. If the software you want to use is not listed, you can click 'Use a custom command' and enter the command for the software.

5. The OBJ file should now open in the selected application, allowing you to view and edit the 3D model as needed.

Using the Command Line Method:

1. Open a terminal window in Ubuntu.

2. Navigate to the directory where your OBJ file is located using the 'cd' command.

3. Use a command-line 3D model viewer such as 'view3dscene' or 'meshlab' to open the OBJ file. For example, you can use the command 'view3dscene yourfile.obj' to open the OBJ file in the view3dscene viewer.

4. The OBJ file should now be displayed in the command-line 3D viewer, allowing you to navigate and interact with the 3D model using the keyboard and mouse.

In addition to these methods, there are also various 3D modeling software available for Ubuntu that support the OBJ file format, such as Blender, FreeCAD, and OpenSCAD. These software packages provide comprehensive tools for viewing, editing, and rendering 3D models in the OBJ format.

With these options at your disposal, you can easily open and work with OBJ files in Ubuntu, whether you prefer using a graphical user interface or the command line. Whether you're a professional 3D designer or just want to explore the world of 3D modeling, Ubuntu provides the tools you need to access and manipulate OBJ files with ease.