I created Box2D. I enjoy all kinds of programming, but specialize in physics and animation. Working on The Legend of California.
Pushing Box3D to the limit. A pyramid with 16290 boxes. Stabilized by contact recycling. www.youtube.com/watch?v=vG4H...
Pushing Box3D to the limitYouTube video by Erin Cattowww.youtube.comI’m happy to announce the release of a new open source 3D physics engine called Box3D. I’ve been working on this project for a few years now, but it represents over 20 years of experience writing physics engines for games. Read more here: box2d.org/posts/2026/0...
Announcing Box3DI’m happy to announce the release of Box3D, an open source 3D physics engine. It is now available on GitHub. Box3D repository You can think of Box3D as a fork of Box2D, extended with many features nee...box2d.orgLarge world support is coming to Box2D v3.2. Uses doubles for body positions but all math is done in relative coordinates using single precision. Around 3% performance loss. www.youtube.com/watch?v=RwQr...
Double precision for larger worldsYouTube video by Erin Cattowww.youtube.comNew recording and replay feature added to Box2D. Uses determinism to exactly reproduce the simulation for your game. Debug your game with all details including ray casts and other queries. Deterministic rollback too. box2d.org/posts/2026/0...
ReplayReplay is a new system I developed for Box2D. The main goal is to allow users to send me files I can use to reproduce bugs. Because Box2D is open source, I can rarely run a user’s game or see their co...box2d.orgThis is the game I've been working on the last four years. It is an incredibly ambitious project made by a small team. www.youtube.com/watch?v=7fax...
The Legend of California - First Look (Wishlist Now)YouTube video by kintsugiyamawww.youtube.comA couple barriers to C development are lack of a fast sorting library and a fast hash set and map. I've found these two libraries to be excellent at providing those. They are macro based, but I think the trade-off is worth it. Both work with C99. github.com/svpv/qsort github.com/JacksonAllan...
Pinched wrists on ragdolls are caused by twist bone poses living in the animation data. Twist bones are procedural and computed based on the pose of animated bones, so they should computed as a post process at runtime to fix this. See www.youtube.com/watch?v=Jkv0... by @bobbyanguelov.bsky.social
I love physics based walking simulations. I'm also pleased the author was successful using Box2D (v3.1?) www.youtube.com/watch?v=aBp-...
AI Cat Learning to RunYouTube video by Pezzza's Workwww.youtube.comThis video is great for teaching the basics of GJK. However, the approach is flawed for computing distance and only works for determining separation true/false. Unfortunately the author has disabled comments and people keep using this and ending up with broken code. www.youtube.com/watch?v=Qupq...
Implementing GJK - 2006YouTube video by Casey Muratoriwww.youtube.comBox2D version 3.1 is released! Blog post: box2d.org/posts/2025/0... Release notes: github.com/erincatto/bo... Documentation: box2d.org/documentation/
Box2D 3.1Version 3.0 was released about 8 months ago. It was a huge update and it needed some refinement. Version 3.1 addresses most of the bugs and build problems. It also introduces some new features and ref...box2d.orgI’ll be speaking about Box2D optimizations at the #GDC2025. I’ll be diving into the details of implementing fast continuous physics. This presentation has a new format I’ve developed recently. I’m really excited to share it! schedule.gdconf.com/session/opti...
Optimizing Continuous Physics in Box2D | 2025 Schedule | Game Developers Conference (GDC)Attend 750 sessions for game designers, programmers, artists, producers, audio, business, and marketing professionals over 5 days at GDC.schedule.gdconf.comTangent speed is a new Box2D surface property that lets you easily make conveyor belts or launch ramps like this. youtu.be/WUxqUSk79nE
Launch rampYouTube video by Erin Cattoyoutu.be