If you're into 3D modeling and design, chances are you've come across OBJ files. These files are commonly used for storing 3D models and are compatible with various 3D modeling software. MeshLab is a popular, open-source software for processing and editing 3D meshes, and it also supports opening OBJ files. Here's how to do it:

1. Download and install MeshLab: If you don't already have MeshLab installed on your computer, you can download it for free from the official website. MeshLab is available for Windows, Mac, and Linux, so you can install it on your preferred operating system.

2. Launch MeshLab: Once MeshLab is installed, launch the software on your computer. You'll be greeted with a user-friendly interface that allows you to work with 3D models and meshes.

3. Open the OBJ file: To open an OBJ file in MeshLab, go to the 'File' menu and select 'Import Mesh...' This will open a file dialog box where you can navigate to the location of your OBJ file. Select the OBJ file and click 'Open' to import it into MeshLab.

4. Explore and manipulate the 3D model: Once the OBJ file is imported, you can explore and manipulate the 3D model using MeshLab's various tools and features. You can view the model from different angles, apply filters and effects, and even make modifications to the mesh if needed.

5. Save or export your work: After working with the OBJ file in MeshLab, you can save your changes or export the modified 3D model to a different file format if necessary. MeshLab supports various file formats, so you can choose the one that best suits your needs.

Opening OBJ files in MeshLab is a straightforward process that allows you to view and edit 3D models with ease. Whether you're a professional 3D designer or just getting started with 3D modeling, MeshLab provides a powerful set of tools for working with OBJ files and other 3D formats. Give it a try and explore the possibilities of 3D design with MeshLab today!