If you're working on game development or design using Source SDK, you may need to export OBJ files to use 3D models in your projects. Here's a step-by-step guide on how to export OBJ from Source SDK.

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

2. Access the Model Viewer: Once your map or model is loaded, access the Model Viewer tool within Source SDK.

3. Select the Model: In the Model Viewer, select the 3D model that you want to export as an OBJ file.

4. Export the Model: After selecting the model, look for the export option within the Model Viewer. Choose the OBJ format as the export file type and set the destination folder for the exported file.

5. Adjust Export Settings: Before exporting, you may have the option to adjust export settings such as scale, rotation, and texture coordinates. Make any necessary adjustments to ensure the exported OBJ file meets your project requirements.

6. Export and Save: Once you've finalized the export settings, proceed to export the 3D model as an OBJ file. Save the file in your chosen destination folder.

7. Import into Your Project: With the OBJ file exported, you can now import it into your game development or design project. Most 3D modeling and game design software support the OBJ format, making it easy to integrate the exported model into your work.

8. Check Compatibility: After importing the OBJ file, be sure to check its compatibility with your project. Ensure that textures, materials, and geometry are correctly preserved in the exported model.

By following these steps, you can successfully export OBJ from Source SDK and incorporate 3D models into your game development and design projects. Whether you're creating immersive environments, character models, or props, mastering the export process will streamline your workflow and bring your creative vision to life.