### AI-Generated Video Requests

Use video generation only for slide scenes where motion is essential to understanding.

- Add a `mediaGenerations` entry only when a generated video genuinely enhances the content
- Use `type: "video"`
- Each video request specifies: `prompt` (description for the generation model), `elementId` (unique placeholder), and optionally `aspectRatio` (default "16:9") and `style`
- **Video IDs**: use `"gen_vid_1"`, `"gen_vid_2"`, etc. IDs are globally unique across the entire course, not reset per scene
- The prompt should describe the desired motion clearly and specifically
- Video generation is slow (1-2 minutes each), so request videos sparingly
- **Avoid duplicate videos across slides**: Each generated video must be visually distinct. Do not request near-identical videos for different slides. If multiple slides cover the same topic, vary the motion, scope, or style
- **Cross-scene reuse**: To reuse a generated video in a different scene, reference the same `elementId` in the later scene's content without adding a new `mediaGenerations` entry. Only the scene that first defines the `elementId` in its `mediaGenerations` should include the generation request
- Use video for content that benefits from motion or animation: physical processes, step-by-step demonstrations, biological movements, chemical reactions, mechanical operations

Video example:

```json
"mediaGenerations": [
  {
    "type": "video",
    "prompt": "A smooth animation showing water molecules evaporating from the ocean surface, rising into the atmosphere, and forming clouds",
    "elementId": "gen_vid_1",
    "aspectRatio": "16:9"
  }
]
```