✍️ handanim

A Python library to create whiteboard-style, hand-drawn animations for educational videos, tutorials or data storytelling.

handanim lets you programmatically animate hand-drawn diagrams, geometric shapes, handwritten text, and visual explanations — ideal for online teaching, explainer videos, and mathematical illustrations.

⭐️ If you like this project, please consider starring it on GitHub! Your support helps the project grow.

✨ Features

• Draw and animate shapes (lines, ellipses, polygons) with a hand-drawn feel
• Fill objects with sketch-style strokes (hatching, scribbles)
• Animate handwritten text using custom fonts
• Export vector images (SVG) or videos (MP4).
• Intuitive Python API for creating scenes and timelines

📷 Example Output

Example 1: Pythagoras Theorem

(Example animation of a Pythagoras Theorem — see examples/pythagoras.py)

Example 2: Square formula

(Example animation of proof of a plus b whole square — see examples/a_plus_b_square.py)

🚀 Quickstart

📦 Installation using Poetry

The easiest way to install all the dependencies is to use Poetry.

# Install dependencies (requires Python 3.13+)
poetry install

# Run example animation
poetry run python examples/pythagoras.py

✏️ Basic Usage

from handanim.core import Scene
from handanim.animations import SketchAnimation
from handanim.primitives import NGon

scene = Scene(width = 800, height = 608)
triangle = NGon(
    center = (400, 304),
    radius = 100,
    n = 3
)
scene.add(SketchAnimation(start_time = 0, end_time = 5), drawable = triangle)
scene.render("triangle_anim.mp4", fps = 30)

📦 Installation using pip

If you prefer using pip instead of Poetry, you can install the main dependencies directly from the requirements.txt file. This method works well for lightweight setups or deployment environments.

# Create and activate a virtual environment (optional but recommended)
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install core dependencies
pip install -r requirements.txt

# (Optional) Install development dependencies
pip install -r dev-requirements.txt

# Run example animation
python examples/pythagoras.py

Make sure you're using Python 3.11+ (as specified in the project).

Installing Cairo

Your system must have the Cairo graphics library installed for pycairo or cairocffi to work correctly. This is a native C library and needs to be installed separately depending on your OS.

✅ On Ubuntu/Debian

sudo apt update
sudo apt install libcairo2 libcairo2-dev

✅ On macOS (using Homebrew)

brew install cairo

✅ On Windows

Use the precompiled binaries:

1. Download the GTK 3 Runtime (which includes Cairo).
2. Install it and add its bin/ folder to your system PATH.
3. Then install Python packages as usual:

pip install -r requirements.txt

Or use the cairocffi + pycairo + pip combo with wheels from Gohlke's unofficial site if needed.

🎬 Installing FFmpeg (Required for Video Rendering)

moviepy uses FFmpeg to write video files (e.g., .mp4). You must have FFmpeg installed and accessible in your system PATH.

✅ On Ubuntu/Debian

sudo apt update
sudo apt install ffmpeg

✅ On macOS (using Homebrew)

brew install ffmpeg

✅ On Windows

1. Download FFmpeg from the official site or a reliable Windows build like gyan.dev.
2. Extract the archive, and add the bin/ folder to your system PATH.
3. Verify installation:

ffmpeg -version

📄 License

This project is licensed under the MIT License.

🤝 Contributing

We welcome contributions!

You can help by:

• Adding new animation primitives (e.g., Bezier curves, arrows)
• Improving rendering quality and styles, caching and optimization.
• Writing example scripts or tutorials
• Reporting bugs and suggesting features

Please see CONTRIBUTING.md (coming soon) for guidelines.

❤️ Inspiration

Inspired by:

• 3Blue1Brown's manim
• RoughJS
• Whiteboard animation videos
• Interactive teaching tools

⭐️ Support handanim!

If you find this project useful, please give it a star on GitHub.

It motivates me to keep improving it and helps others discover it!

✨ Made with love by Subhrajyoty Roy

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🧠 Internals (Architecture)

1. core: Core capabilities.

   • drawable.py: Defines the structure that can be drawn.
   • styles.py: Defines the styling oriented options that can be configured.
   • draw_ops.py: Defines the opsets, the basic structure that is used to draw. Along with the rendering logic for the opsset into the cairo context.
   • utils.py: Some utility functions that does not fit anywhere else
   • animation.py: Defines the animation structures.
   • scene.py: Defines the scene, which is the main entry point for the user.

2. Models.

   • Ops and OpsSet: Describe vector drawing instructions.
   • Scene: Collects objects and sequences them in time.
   • Handwriting: Converts strokes from mock or real fonts into draw operations.

💡 Features Coming soon

1. Arrows
2. Flowcharts diagrams
3. Importing images and videos into the scene.
4. Autofitting content based on the size of textbox
5. Showcasing tabular data with headers.