✳✲✱ Official Force2D v4.3.6 ✱✲✳ A 2D rigid-body physics engine for Scratch / TurboWarp. Feel free to use it! Credits aren't required, but they're always appreciated. [ What's New in v4.3.6? ] This is a fairly large update with several changes to the engine: • List Pool Architecture: Reworked parts of the core to make object management more efficient. • Compound Bodies: Added support for building bodies from multiple shapes. • New Shape: Added Capsules. • Manifold Pairs: Added contact manifold caching to improve efficiency and stability. [ Core Features ] • Supported Shapes: Circle, Rectangle, Polygon, Capsule, and Compound Bodies. • Joint Systems: Distance Joint, Revolute Joint, and Mouse Joint. [ Optimizations & Technical Details ] • Architecture: Data-Oriented Design, List Pool structure. • Efficiency: Dynamic BVH, Improved SAT Collision Detection. • Stability: Velocity-Based Solver, Block Solver, K-Matrix Impulse, Baumgarte Stabilization. • Performance: Manifold Pairs Caching, Warm Start, Sleep Islands. [ About Force2D ] • Released on 2026/08/23 (Age 20) • The engine is inspired by mathematical approaches used in Box2D. • ⚠️ Physics calculations can be fairly demanding, so standard Scratch may experience some lag. TurboWarp at 60FPS is recommended. It's still an ongoing project, and there is definitely room for improvement. I'm mainly making it to learn more about physics simulation and see how far I can take it. [ Special Thanks ] Thanks to @komafami for the support and advice while I was figuring out the mathematics and implementation. It helped a lot! [ Version History ] 2026/08/23 - v4.3.6 (Major Update) Reworked the core using a List Pool system. Added manifold pairs, compound bodies, and capsule shapes, along with various efficiency and stability improvements. 2026/06/24 - v3.1.3 Fixed an issue where joints stopped working when rigid bodies entered sleep mode. 2026/05/25 - v3.1.2 Fixed a rigid body removal bug by rebuilding the BVH tree / Hash grid. Also fixed mouse-drag force tracking and BVH renderer zooming issues. 2026/05/14 - v3.1.1 Added Weld Joint support and fixed several joint stability issues. 2026/05/12 - v3.0.1 Fixed issues involving joint-connected sleeping objects and warm-start ID pairs. 2026/05/12 - v3.0.0 Initial release of the Force2D core. #physics #physic #engine
