Main
Chipmunk

Screenshots:
Go to the screenshot gallery.
Videos:
Features:
- Designed for 2D video games.
- Circle, convex polygon, and line segment collision primitives.
- Multiple collision primitives can be attached to the same rigid body.
- Fast collision detection by using a spatial hash for the broad phase.
- Extremely fast impulse solving by utilizing Erin Catto’s contact persistence algorithm.
- Support for collision callbacks based on object types.
- Impulses applied to contact points can be retrieved after the impulse solver has finished.
- Several kinds of joints available.
- C99 implementation, no external dependencies.
- Ruby extension available.
- Simple, read the documentation.
- Unrestrictive MIT license.
Download:
Source + Demos
Tutorials:
- Moon buggy tutorial (XCode project)
- Create a simple side scrolling vehicle game. (Complete with soft suspension!)
- Shows basic Chipmunk usage including initialization and usage of joints.
- More to come
Community:
Chipmunk Forums at Slembcke.net
Testimonials
”I had been working on my own physics code for months, trying to make it as fast as possible – then I took 3 days to change out my setup for chipmunk and things improved considerably. Chipmunk is fast and easy, I recommend it.” – Derek Arndt (Biofilm)
Logos

Want to throw a logo on your splash screen to show how much you appreciate Chipmunk? Frank Condello was gracious enough to make a logo for me. A couple variations are available here.
SVN:
Chipmunk is currently hosted as a Google Code Project. Go there now.
Acknowledgments:
- Box2D:
- Erin Catto’s Box2D code was the most useful reference that I used when creating Chipmunk. His contact persistence algorithm is the main reason why Chipmunk is so fast.
- Optimized Spatial Hashing for Collision Detection of Deformable Objects
- The best article I could find on spatial hashing. Their hash function seems to perform very well.
- Nonconvex Rigid Bodies with Stacking
- My previous implementation was based on this paper. I only implemented part of the algorithm before deciding that something simpler would be better suited for real time.
- Physics for Game Developers
- This book is a good reference for a lot of the math you’ll need, but is far from a good reference on implementing a physics engine.
Logo by Frank Condello, Chipmunk sillouette by Kelvin Nishikawa