A Python automation tool for recording OpenCap motion capture animations using the OpenCap web viewer.

• Automated recording of OpenCap motion capture comparisons
• Multiple camera angle recordings
• Customizable wait times and recording loops
• Automatic file handling and cleanup

• Python 3.7+
• Google Chrome browser
• Internet connection (to access the OpenCap viewer website)

1. Create and activate a Python virtual environment (recommended):

python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

2. Install Python dependencies:

pip install -r requirements.txt

Use the Python script to automate the recording process:

python automation.py path/to/first.json path/to/second.json output_video.webm

Optional arguments:

• --wait: Adjust loading wait time (default: 5 seconds)
• --loops: Number of camera angle changes (default: 3)

Example:

python automation.py test1.json test2.json comparison.webm --wait 10 --loops 4

The automated recording cycles through these views:

1. Front view (0°)
2. Side view (90°)
3. Back view (180°)
4. High angle diagonal view (45°)

The script expects OpenCap JSON files with the following structure:

{
  "time": [...],
  "bodies": {
    "body_name": {
      "translation": [...],
      "rotation": [...],
      "attachedGeometries": [...]
    }
  }
}

1. If the video doesn't download:

   • Check Chrome's download permissions
   • Ensure the output directory is writable
   • Verify your internet connection

2. If models don't appear:

   • Verify JSON file format
   • Check that the files are valid OpenCap JSON files
   • Increase the wait time using --wait

3. If camera controls don't work:

   • Ensure the browser window is focused
   • Check that the website has loaded properly

1. Fork the repository
2. Create your feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request