To create a Gemini 3D image, specifically using Google's Gemini AI tool known as "Nano Banana" (Gemini 2.5 Flash Image), follow these steps:

1. Open Gemini AI Studio through the Gemini app or website (gemini.google.com).
2. Select the Gemini 2.5 Flash Image model, also called Nano Banana.
3. Upload a clear, well-lit photo of the subject you want to turn into a 3D image or figurine.
4. Enter a detailed text prompt describing the style and setting of the 3D image you want. For example, a popular prompt format is:
   • "Create a 1/6 scale commercialized figurine of the characters in the picture, in a realistic style, in a real environment. The figurine is placed on a computer desk. The figurine has a round transparent acrylic base, with no text on the base. The content on the computer screen is the ZBrush modeling process of this figurine. Next to the computer screen is a BANDAI-style toy packaging box printed with the original artwork."
5. Click "Generate" to let the AI create the 3D figurine image.
6. Save the generated 3D image to your device.

Tips for best results:

• Use high-quality, well-lit photos.
• Be very descriptive and specific in your prompts.
• Include props or environment details for realism.
• Adjust and iterate on the prompt for improved outcomes.

This method allows anyone to easily create realistic 3D figurine-style images from their photos using Gemini AI's advanced image generation and editing model.