If you're working on game development or 3D modeling projects using Source SDK, you may need to export OBJ files for use in other software or game engines. Here's a step-by-step guide on how to do it.

1. Launch Source SDK: Open Source SDK and load the map or model you want to export as an OBJ file.

2. Open the Model Viewer: Once you have the map or model loaded, open the Model Viewer tool within Source SDK.

3. Select the Object: In the Model Viewer, select the object you want to export as an OBJ file. You can use the navigation controls to rotate and zoom in on the object to make sure you have the right selection.

4. Export as OBJ: With the object selected, look for the export options in the Model Viewer. Choose the export format as OBJ and set any preferences or options for the export, such as texture settings or scale.

5. Save the OBJ File: After configuring the export settings, click the export button and choose a location to save the OBJ file on your computer.

6. Open in 3D Software: Once the OBJ file is saved, you can open it in your 3D modeling software or game engine of choice to continue working on your project.

Remember, when exporting OBJ files from Source SDK, it's important to consider any texture or material settings to ensure the file is compatible with the software or game engine you plan to use.

By following these steps, you can easily export OBJ files from Source SDK for use in your game development and 3D modeling projects. This process allows you to seamlessly transfer assets between different software and tools, making it easier to bring your creative vision to life.

Whether you're creating custom models for a Source engine game or producing 3D assets for other projects, knowing how to export OBJ files from Source SDK is a valuable skill that can streamline your workflow and enhance your creativity.