Browser-based N-body gravity sandbox built with Next.js, TypeScript, and Canvas 2D.
Live app: https://gravity-sandbox-eight.vercel.app
Drop asteroids, planets, giants, stars, black holes, and dark matter onto a space canvas. Drag while placing to set initial velocity, then watch the bodies orbit, merge, eject, collapse, or get absorbed.
The simulation uses custom TypeScript physics with softened N-body gravity, Velocity Verlet integration, collision merging with momentum conservation, Roche-limit debris, dense-scene solver optimization, and real-time Canvas rendering.
- Real-time gravitational interaction between all bodies
- Click and drag body placement with velocity arrows
- Movable and resizable dashboards
- Teach mode on by default with live event logging
- 2D and fake 3D view modes
- Gravity gun pull/repel tool
- Orbit prediction ghost paths
- Wormholes with velocity-preserving teleport
- Supernova, meteor storm, and system collapse controls
- WebM replay export
- Presets for Solar System, binary stars, figure-eight, galaxy collision, galaxy mode, and moon capture
| Desktop chaos view | Mobile dashboard view |
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More details are in docs/SCREENSHOTS.md.
npm install
npm run devOpen http://localhost:3000.
npm run test:run
npm run lint
npm run build
npm run test:e2eThe current production deployment was verified with unit tests, lint, production build, desktop/mobile Playwright tests, Vercel inspect, and Vercel error log checks. See docs/TESTING.md.