Open-source alternatives to PhysicsJS

This project is a multi-purpose web platform serving as a canvas 2D game engine, a frontend engineering blog, and a markdown static site generator. It functions as a web graphics showcase and a technical knowledge base for sharing architectural decisions and performance optimizations. The platform implements a high-performance graphics framework using low-level drawing APIs, integrating skeletal animation and web physics for collision detection and realistic motion of two-dimensional objects. It simultaneously operates as a system for converting markdown source files into pre-rendered HTML pa

Rapier is a cross-platform physics engine and rigid body dynamics solver designed for 2D and 3D simulations. It functions as a collision detection system and a robotics simulation framework, providing a consistent API for calculating physical interactions across different environments. The engine distinguishes itself with specialized robotics capabilities, including a toolkit for importing URDF and STL models to control multibody chains. It supports precise mechanical movement through inverse kinematics calculations and the application of PID controllers for dynamic body control. The simulat

JoltPhysics is a high-performance C++ physics engine designed for multi-threaded simulation of 3D rigid bodies and soft bodies. It serves as a deterministic simulation framework, ensuring identical results across different platforms and architectures to support networked synchronization. The engine distinguishes itself through a focus on concurrent execution across multiple CPU cores to handle large numbers of active bodies. It provides specialized systems for vehicle physics, including wheeled and tracked models, as well as soft body physics for deformable objects and cloth. The simulation

melonJS is a lightweight HTML5 game engine for building 2D games in the browser using JavaScript. It provides a complete framework for sprite animation, tilemap loading, physics simulation, input handling, and audio playback, with a unified rendering system that automatically switches between WebGL and Canvas2D backends without code changes. The engine distinguishes itself through several integrated capabilities. It features a per-sprite shader pipeline for custom fragment shader effects, a SAT-based collision engine with swappable physics adapters (including built-in SAT, Matter.js, and Plan

LibGDX is a Java-based framework designed for cross-platform game development, enabling the creation and deployment of 2D and 3D games across desktop, mobile, and web environments from a single codebase. It functions as a comprehensive library that abstracts hardware-accelerated graphics, audio, input, and file system access, providing a unified interface for developers to manage game logic and application lifecycles. The framework distinguishes itself through a high-performance architecture that prioritizes efficiency and native interoperability. It utilizes a batch-oriented graphics pipelin

Urho3D is a cross-platform 3D game engine written in C++. It uses a component-based scene graph to compose game objects from nodes and attached components, separating transforms from behaviors for modular design. The engine integrates AngelScript and Lua scripting for game logic, uses the Bullet library for physics simulation, and renders scenes with OpenGL or Direct3D through forward, deferred, or light pre-pass pipelines with customizable render passes and shadow mapping. The engine distinguishes itself with a built-in visual scene and UI editor for composing 3D worlds and interface layouts

planck.js is a 2D rigid body physics engine for JavaScript and HTML5, based on Box2D. It provides a framework for simulating physical interactions and calculating the motion of solid objects within a two-dimensional virtual environment. The engine is designed for cross-platform web gaming, enabling the implementation of rigid body dynamics across different web browsers and devices. The library manages simulation through a constraint-based physics solver and rigid body state management. It utilizes iterative impulse resolution, semi-implicit Euler integration, and dynamic AABB tree partitioni

FlappySwift is a side-scrolling arcade game implementation built for Apple platforms. Developed using the Swift programming language, this 2D game project features a physics-based environment where a player controls a character to avoid obstacles. The project utilizes the SpriteKit framework to handle rigid body dynamics, gravitational forces, and sprite-based rendering. Game flow is managed through a state machine that controls transitions between the start menu, active gameplay, and game over screens. The implementation covers 2D physics simulation, including bounding-box collision detecti

mujoco_menagerie is a curated library of physical robot specifications and XML model definitions designed for standardized dynamics and contact simulation. It provides a collection of high-quality robot model files for humanoids, quadrupeds, and manipulators, alongside detailed kinematic and inertial parameters used to reproduce real-world robot behavior in virtual environments. The project serves as a repository of robotics simulation assets and MJCF model definitions optimized for accuracy. It includes standardized model libraries specifically for bipedal, quadrupedal, and humanoid hardware

cannon.js is a JavaScript 3D physics engine designed for calculating rigid body dynamics and collisions in three-dimensional space. It functions as a rigid body dynamics engine that models mass, friction, and velocity to determine object movement, while providing a mathematical framework for applying physical constraints and joints. The engine supports a variety of collision volumes, including spheres, boxes, convex polyhedrons, heightfields for terrain simulation, and complex triangle meshes. It provides tools for identifying intersections between these shapes and calculating the exact areas

Bullet3 is a professional physics simulation engine designed for calculating rigid body, soft body, and collision dynamics within 3D environments and robotics applications. It functions as a computational framework for determining complex geometric intersections and contact manifolds between objects in simulated space. The library distinguishes itself through a distributed rendering framework that scales heavy graphical workloads and scene generation tasks across large clusters of machines. This capability enables the production of massive datasets by distributing complex scene generation acr

Flame is a 2D game engine for Flutter and Dart. It provides a component-based game framework for managing entities and their lifecycles through a hierarchical architecture, alongside a dedicated system for game asset management and input handling. The engine distinguishes itself through a specialized integration layer for external physics engines to handle rigid body dynamics and collision detection. It also features a high-performance task model that uses isolates to offload heavy computations and prevent main thread blocking. The framework covers a broad range of capabilities including vis

Pinocchio is a multi-body dynamics engine and rigid body physics library designed for computing forward and inverse kinematics and dynamics for articulated rigid-body systems. It functions as a robot kinematics solver and model parser, enabling the analysis of complex robotic systems through kinematic and dynamic computations. The project distinguishes itself with specialized capabilities for constrained dynamics, including the calculation of contact impulses and centroidal momentum. It provides a parallel processing collision detection system for computing minimal distances between rigid bod

This project is an open-source 3D game engine designed for building high-fidelity games, simulations, and cinematic environments. It functions as a robotics simulation platform with native integration for ROS 2 to model robot controllers and sensors. The engine features a multi-threaded Forward+ physically based renderer that supports hardware-accelerated ray tracing and global illumination. The system is built on a modular extension architecture using Gems to add or replace features without modifying core binaries. It includes a native SDK for AWS cloud integration, enabling IAM authenticati

Cocos2d-x is a high-performance C++ game development framework designed for building and deploying interactive applications across mobile, desktop, and web platforms. It functions as a cross-platform game engine that utilizes an entity-component system to manage object lifecycles, behaviors, and spatial relationships within a unified codebase. The engine is distinguished by its specialized 2D graphics rendering pipeline, which is optimized for hardware-accelerated performance when displaying sprites, particle effects, and skeletal animations. It provides developers with low-level access to gr

LumixEngine is a high-performance C++ 3D game engine designed for building interactive 3D applications. It is built on a data-oriented component system that organizes objects in contiguous memory blocks to maximize CPU cache performance. The engine features a dynamic binary plugin architecture for loading external modules at runtime and an embedded scripting virtual machine that exposes internal logic for external control without recompilation. Computational workloads are managed via a task-based parallel execution model that distributes jobs across multiple processor cores. The framework in

LittleJS is a lightweight HTML5 2D game engine designed for building web games using Canvas and WebGL without external dependencies. It integrates a WebGL sprite renderer, a 2D physics engine for arcade-style collisions and rigid-body dynamics, and a grid-based A* pathfinding system for entity navigation. The engine is distinguished by its procedural audio synthesizer, which generates music and sound effects at runtime using parameter arrays to minimize file sizes. It also features a comprehensive graphics pipeline that supports custom fragment-shader post-processing and a dynamic 2D lighting

Flame is a 2D game engine and framework for Flutter. It provides a component-based architecture to organize scene entities and manage their lifecycles through a structured hierarchy of game objects, coordinated by a consistent game loop. The engine includes a graphics library for rendering animated sprites, particle effects, and external textures. It features a 2D physics integration layer that supports rigid body dynamics and collision detection between entities. The framework covers additional capabilities for game engineering, including user input capture for gestures and gamepads, audio

verlet-js is a JavaScript 2D physics engine and Verlet integration library used to simulate point masses and geometric constraints. It functions as a computational tool for calculating particle movement and structural interactions to create stable physics animations in browser environments. The project acts as a geometric constraint solver that enforces fixed distances and angles between interconnected nodes. This allows for the modeling of complex physical shapes and structures, such as cloth or rigid bodies, by iteratively adjusting particle positions. The engine includes a canvas animatio

Chrono is a multi-physics simulation suite that functions as a multibody dynamics simulator, a finite element analysis tool, and a robotics simulation framework. It provides specialized solvers for fluid-solid interaction and distributed physics engines capable of synchronizing multiple agents across a network. The project features a dedicated pipeline for converting CAD assemblies into simulation-ready formats and integrates directly with robot operating systems to validate autonomous control logic and sensors. It differentiates itself through the use of WebAssembly for portable browser-base

Coffee-Physics is a lightweight physics engine designed for two-dimensional particle simulation within web environments. It provides a framework for managing the movement and physical interactions of individual objects across a coordinate system, utilizing a collection of mathematical functions to calculate trajectories and collision responses. The library employs Verlet-based integration to maintain stability by tracking coordinate history, avoiding the need for explicit velocity or acceleration variables. It enforces deterministic behavior through fixed-step time stepping, which ensures con

cocos2d-objc is an Objective-C 2D game engine designed for developing interactive games and applications. It serves as a cross-platform game framework that enables the deployment of a shared codebase across iOS, tvOS, and macOS. The project features a hardware-accelerated 2D renderer utilizing OpenGL and Metal to display sprites, tile maps, and particle effects. It includes a dedicated OpenAL audio engine for managing music and spatialized sound effects, alongside a cross-platform input handler for processing touch, mouse, keyboard, and accelerometer events. The framework provides capabiliti

cocos2d-iphone is a framework for 2D game development and the creation of two-dimensional graphical applications. It enables cross-platform development for iOS and macOS using Objective-C and high-performance graphics rendering. The project provides tools for building interactive environments, including the creation of orthogonal, isometric, or hexagonal tile-based maps. It supports the implementation of rigid body dynamics and collision detection through a 2D physics simulation system. The framework covers a broad range of capabilities, including sprite-based rendering, audio playback manag

Space Station 14 is a C# multiplayer game and roleplay simulation framework. It is built upon an Entity-Component-System (ECS) game engine that separates logic into systems and data into components to manage complex entity interactions. The project functions as a grid-based physics simulator with a YAML data-driven prototype system for defining game objects. The project features a specialized 2D sprite rendering engine that maps server-side appearance data to client-side shaders. It implements a networking model with client-side prediction and dirty-flagged state synchronization to reduce inp

Cyclone Physics is a three-dimensional rigid body physics engine designed for game development. It provides a framework for simulating the motion, rotation, and physical interactions of solid objects by applying fundamental laws of mechanics. The library utilizes discrete time integration to update object positions and velocities across fixed intervals. It manages complex scenes through a bounding volume hierarchy and employs impulse-based collision resolution to maintain momentum during contact. To handle simultaneous interactions, the engine uses an iterative velocity solver that repeatedly

jMonkeyEngine is a Java-based 3D game engine and cross-platform graphics framework. It provides the core tools necessary for developing three-dimensional games and interactive simulations, focusing on real-time rendering and the management of spatial environments. The engine includes a dedicated 3D physics simulation toolkit for handling rigid body dynamics and collision detection. It also features a game asset pipeline for importing and managing 3D models, textures, and audio files during runtime. The framework covers broad capability areas including 3D scene rendering, physics-based simula

Pyxel is a Python-based retro game engine designed for creating pixel-art applications with vintage aesthetics. It functions as a pixel art framework that emulates classic hardware limitations through fixed-resolution displays, constrained color palettes, and a 2D tilemap engine for rendering scaled sprites and grid-based game worlds. The engine features a dedicated MML audio synthesizer that uses Macro Language notation to compose and play back retro-style sound sequences. It also includes capabilities for seed-based background music generation and the playback of raw PCM audio data for cust