If you're looking to bring your 2D designs from Adobe Illustrator into the world of 3D modeling, exporting your artwork as an OBJ file is a crucial step. Here's a guide on how to save your Illustrator file as an OBJ.

1. Open your Illustrator file: Start by opening the file that you want to export as an OBJ in Adobe Illustrator.

2. Prepare your artwork: Make sure that your artwork is organized and grouped properly. If you have multiple layers, consider merging them into a single layer for easier export.

3. Export as SVG: Before converting to OBJ, you'll need to export your artwork as an SVG file. Go to File > Save As and choose SVG as the file format. This step ensures that your vector artwork is preserved for the 3D modeling process.

4. Convert SVG to OBJ: Illustrator doesn't have a built-in feature to save directly as an OBJ file, so you'll need to use a third-party tool or software to convert the SVG file to OBJ. There are various free and paid options available online for this conversion.

5. Check settings: When converting the SVG to OBJ, make sure to check the export settings to ensure that the 3D model retains the desired scale, dimensions, and details from your original artwork.

6. Save the OBJ file: Once you've adjusted the settings, proceed to save the SVG file as an OBJ format. Choose a location on your computer to save the file.

7. Import into 3D software: With the OBJ file saved, you can now import it into your preferred 3D modeling software such as Blender, Maya, or 3ds Max. The OBJ file should retain the vector qualities of the original Illustrator artwork, allowing for further manipulation and 3D rendering.

By following these steps, you can seamlessly transition your 2D designs from Illustrator into the realm of 3D modeling. Whether you're working on product prototyping, animation, or 3D printing, saving your Illustrator file as an OBJ file opens up new creative possibilities.