Creating an AI engine that generates images based on text queries involves using a pre-trained model like OpenAI's DALL-E or similar models. However, as these models are quite large and require substantial computational resources, you typically use a pre-trained model available via an API.

Creating an AI engine that generates images based on text queries involves using a pre-trained model like OpenAI's DALL-E or similar models. However, as these models are quite large and require substantial computational resources, you typically use a pre-trained model available via an API.

Below is an example of how you might use a service like OpenAI's DALL-E through the API. Note that you need access to the OpenAI API and an API key to run this code.

First, ensure you have the OpenAI package installed:

```sh
pip install openai
```

Here's a simple Python script that generates an image based on a text query:

```python
import openai
import requests
from PIL import Image
from io import BytesIO

# Replace 'your-api-key' with your actual OpenAI API key
openai.api_key = 'your-api-key'

def generate_image(prompt):
    # Call the OpenAI API to generate an image
    response = openai.Image.create(
        prompt=prompt,
        n=1,
        size="512x512"
    )
    
    image_url = response['data'][0]['url']
    return image_url

def download_image(url):
    response = requests.get(url)
    img = Image.open(BytesIO(response.content))
    return img

if __name__ == "__main__":
    # Your text prompt
    prompt = "A futuristic cityscape at sunset"
    
    # Generate image URL from the prompt
    image_url = generate_image(prompt)
    
    # Download and show the image
    img = download_image(image_url)
    img.show()
    # Save the image
    img.save("generated_image.png")
```

### Explanation:

1. **Install OpenAI package**: Ensure you have the `openai` package installed.
2. **Set up API Key**: Replace `'your-api-key'` with your actual OpenAI API key.
3. **Generate Image**:
   - `generate_image(prompt)` function sends a request to the OpenAI API with your text prompt.
   - The API returns a URL of the generated image.
4. **Download and Display Image**:
   - `download_image(url)` function downloads the image from the provided URL.
   - The image is displayed using the PIL library and saved to the local file system.

This script assumes you have access to the OpenAI API and the required permissions to generate images. If you're looking for a different model or a locally running version, you'd need to look into models like VQ-VAE-2, BigGAN, or training a model using libraries like TensorFlow or PyTorch, but these are significantly more complex and resource-intensive.