If you're a 3D modeling enthusiast or work with 3D objects, you may come across .obj files that you need to open and view on your Ubuntu system. .obj files are commonly used for 3D modeling and contain information about the geometry, texture, and materials of 3D models. Here's a step-by-step guide on how to open .obj files in Ubuntu:

1. Install a 3D modeling software: The first step to opening .obj files in Ubuntu is to have a 3D modeling software that supports .obj file format. Blender is a popular open-source 3D modeling software that works well on Ubuntu and supports a wide range of file formats, including .obj. Install Blender by opening a terminal and running the following command:

```

sudo apt install blender

```

2. Open the .obj file in Blender: Once you have installed Blender, you can simply open the application and go to 'File' > 'Import' > 'Wavefront (.obj)'. Navigate to the location where your .obj file is saved and select it to open it in Blender.

3. Use a dedicated .obj file viewer: If you prefer to use a dedicated .obj file viewer, you can try using MeshLab. MeshLab is an open-source, portable, and extensible system for the processing and editing of unstructured 3D triangular meshes. You can install MeshLab by running the following command in your terminal:

```

sudo apt install meshlab

```

After installing MeshLab, you can open it and use the 'File' > 'Import Mesh' option to open your .obj file.

4. Check for other 3D modeling software: In addition to Blender and MeshLab, there are other 3D modeling software compatible with Ubuntu that support .obj file format. Some of these include FreeCAD, OpenSCAD, and Wings 3D. You can explore these options and choose the one that best suits your needs.

By following these simple steps, you can easily open and view .obj files in Ubuntu. Whether you choose to use Blender or a dedicated .obj file viewer like MeshLab, you'll be able to work with 3D models and explore their geometry, textures, and materials with ease on your Ubuntu system.