google-deepmind/mujoco_menagerie
Mujoco Menagerie
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 to ensure consistency across different physics simulations.
Features
- Robot Model Libraries - Provides a curated collection of high-quality robot model files for humanoids, quadrupeds, and manipulators.
- Robot Model Repositories - Provides a curated set of pre-configured XML model definitions optimized for accurate dynamics and contact simulation.
- Hardware-Accelerated Simulations - MuJoCo runs physics simulations on GPUs and TPUs by utilizing XLA-compatible implementations.
- Multibody Dynamics Simulators - Utilizes generalized coordinates and optimization-based dynamics to simulate complex articulated multibody systems.
- Robotics Simulators - Provides standardized 3D assets and kinematic specifications for simulating diverse robot hardware and environments.
- Domain Randomizations - Varies physical properties across a batch of simulation worlds to improve sim-to-real generalization.
- Robotic Physics and Sensor Simulators - Simulates complex interactions between robots and objects within a physics-enabled environment.
- Physical Robot Specifications - Provides detailed kinematic and inertial parameters to reproduce real-world robot behavior in virtual environments.
- Robot Model Importers - Imports robot models from XML or binary files and compiles them into a simulation-ready format.
- Robotic Model Parsers - Compiles model specifications into a usable internal representation to initialize the simulation environment.
- Sensor and Actuator Drivers - Implements simulation models for motors, pneumatic cylinders, hydraulic systems, and biological muscles.
- Kinematic Joint Definitions - Implements degrees of freedom between bodies using free, ball, slide, or hinge joint types.
- Hierarchy Construction - Builds the physical hierarchy of the model using bodies, joints, and nested parent-child relationships.
- Mass Property Overriding - Allows manual specification of mass and diagonal inertia matrices to control physical behavior.
- Collision Detection - Identifies active contacts between geometric entities using GJK/EPA algorithms.
- Mechanical Joint Constraints - Implements degrees of freedom between bodies using free, ball, slide, or hinge joint types.
- Physics Solvers - Evolves the simulation state forward by computing physical interactions using configurable solvers.
- Articulated Body Simulators - Enforces equality constraints to connect bodies at anchor points or weld them together rigidly.
- Robot Model Format Converters - Parses and compiles robot model files between MJCF, URDF, MJB, and TXT formats.
- Simulation Loops - Advances the physical state using a numerical integrator and integrated control callbacks.
- Simulation Steppers - Computes the next state of the physical scene by stepping the simulation forward in time.
- 3D Geometry Import - Loads triangulated geometry from STL, OBJ, or MSH files to define visual and collision shapes.
- Actuator Modeling - Provides the ability to define components that apply forces to joints and bodies to drive simulated motion.
- Kinematics Simulators - Adds detailed kinematic attributes to joint primitives to describe body movement and rotation.
- Forward Dynamics Solvers - Computes the time-derivative of the system state, including accelerations and sensor data.
- Inverse Dynamics Solving - Determines the required joint torques to achieve specific accelerations for computed torque control.
- Kinematic Coordinate Frames - Converts positions and orientations between local, global, and center-of-mass coordinate systems.
- Constraint Solvers - Tunes numerical optimization algorithms and friction cone models to balance accuracy and performance.
- Constraint Force Optimization - Computes global constraint forces as the solution to a convex optimization problem.
- Physical Model Composition - Allows the creation of complex robot models by attaching bodies, frames, and specifications to one another.
- Kinematic Tree Representations - Organizes bodies and joints in a nested hierarchy to establish spatial relationships and degrees of freedom.
- Compute Graph Captures - MuJoCo records a sequence of kernel launches into a CUDA graph to reduce overhead during simulation steps.
- Parallel Trajectory Generation - Distributes environment interactions across multiple CPU cores to accelerate trajectory collection.
- Spatial Pose Management - MuJoCo returns the 3D position or unit quaternion orientation of a spatial frame.
- Physics Simulation - Configures global physics parameters such as gravity, wind, and timestep for the simulation environment.
- Deformable Mesh Simulation - Simulates 1D, 2D, or 3D flexible elements that preserve shape via passive constraint forces.
- Differentiable Physics Engines - Creates loop joints or mechanical couplings by defining differentiable scalar or vector functions.
- Parallel Simulations - Runs multiple physics worlds simultaneously across CPUs, GPUs, or TPUs using CUDA or JAX.
- Parallel Rendering - Generates pixel observations across multiple parallel simulation worlds using a hardware-accelerated batch renderer.
- Friction and Restitution Systems - Specifies explicit collision properties and anisotropic friction for specific pairs of geometries.
- Physical Environment Simulation - Sets global simulation options and compiler flags to control the physics environment.
- Mesh and Model Loading - Loads triangulated OBJ or STL files to define collision hulls and infer inertial properties.
- Electrical Actuator Simulation - Models electrical actuators with resistance, inductance, thermal dynamics, and cogging torque.
- Servo Positioning - Provides actuators that apply force based on position feedback gains and optional first-order filters.
- Muscle Actuator Modeling - Simulates muscle behavior using force-length-velocity curves and activation dynamics.
- Collision Filtering - Replaces default collision mask logic to determine which geometry pairs trigger collisions.
- Custom Collision Routines - Replaces built-in pairwise collision functions for specific geometry types to change how intersections are computed.
- Custom Actuator Dynamics - Allows the definition of custom activation dynamics, gains, and biases for user-defined actuators.
- Contact Pair Configuration - Explicitly defines contact pairs or excludes specific body pairs to override automated collision detection.
- Simulation State Vector Snapshotting - Stores a library of state vectors including joint positions and control inputs for simulation initialization.
- 3D Asset Managers - Supports the loading of various 3D mesh and scene formats including OBJ, STL, and USD.
- Simulation Island Partitioners - MuJoCo increases performance by partitioning degrees of freedom into independent disjoint sub-graphs solved in parallel.
- 3D Scene Exporters - Saves scenes and trajectories in USD format for high-quality rendering in external software.
- 3D Model Exporters - Transforms transient physics model definitions into persistent 3D file formats for long-term storage.
- Physical Material Properties - Defines surface and material properties to accurately control friction and restitution during collisions.
- Fixture Shape Definitions - Defines physical boundaries for primitive or mesh shapes to manage object collisions.
- Ray and Shape Casting - Calculates intersection distances between 3D lines and geometry surfaces to detect proximity.
- Equality Constraints - Creates mechanical couplings and loop joints by imposing differentiable equality constraints on bodies and joints.
- Cable Simulation Hierarchies - Simulates inextensible cables by expanding macros into chains of bodies connected by ball joints.
- Unilateral Constraints - Implements rotation and length limits for joints and tendons using range and margin parameters.
- Physics World Debugging Tools - Includes an interactive viewer for inspecting and testing the internal state of physical simulations.
- Simulation Tick Callbacks - Injects custom logic into the physics engine via global callbacks to modify behavior or define forces.
- Programmable Model Modification - Creates and modifies simulation models through a data structure that maps directly to XML definitions.
- Programmatic Model Editing - Programmatically creates and modifies robot models, including the addition of bodies, geoms, and meshes.
- Simulation Keyframe Management - Saves and restores snapshots of joint positions, velocities, and actuator states to reset the system.
- Interactive Simulations - Provides an interactive OpenGL window for model rendering, camera control, and sensor plotting.
- Simulation Logic Extensions - Inserts user-defined logic into the computational pipeline to implement custom sensors and actuators.
- Simulation Scene Composition - Composes complex scenes by including multiple XML files, allowing shared assets and reusable robot components.
- Simulation State Integration - Implements numerical integration methods to advance the simulation state over discrete timesteps.
- Soft Body Simulations - Calculates contact dynamics using a soft contact model to balance accuracy and efficiency.
- Multibody Scene Composition - References physics model files directly within larger 3D scenes using standard composition arcs.
- 3D Simulation Rendering - Provides 3D visualization of simulation models and decorative elements like contact points.
- Constructive Solid Geometry Kernels - Implements a system for building complex 3D objects by combining geometric primitives and height fields.
- OpenGL 3D Pipelines - Sets up an OpenGL context to generate images of simulations without displaying a window.
- Collision Shapes - Implements custom signed distance functions via plugins to define specialized collision shapes.
- Mesh-Based Collision Geometry - Attaches geometric primitives or meshes to bodies to determine their physical boundaries.
- Non-Convex Collision Handling - Implements custom collision logic to handle intersections for non-convex meshes.
- Signed Distance Field Representations - Specifies custom shapes using signed distance fields to enable mesh-free collision detection.
- Physics-to-USD Conversions - Transforms MJCF files into USD assets using specialized schemas to ensure faithful physical representation.
- USD Asset Importers - Loads 3D assets from USD files to define the geometry and physical properties of simulation objects.
- Force Limiting - Simulates hardware limitations by clamping control inputs or output forces at the actuator and joint levels.
- Biomechanical Simulations - Simulates muscle-tendon actuators using scaled length-velocity functions to approximate biological force production.
- Contact Parameter Tuning - Defines friction coefficients, margins, and priority rules to determine how colliding geometries interact.
- Control Law Implementations - Allows defining custom control and applied force vectors based on the current position and velocity.
- Signed Distance Fields - MuJoCo calculates the smallest signed distance between two geoms or along a ray from a camera.
- Parallelized Dynamics Sampling - MuJoCo executes multiple forward or inverse dynamics calls across a thread pool using private data structures.
- Parallel Scene Simulations - Provides an interactive viewer to observe multi-world simulations in real-time.
- Interactive Dynamics Probing - Manipulates body poses or applies external forces and torques in real-time to probe system dynamics.
- Joint Jacobian Computations - Provides efficient computation of state-transition and control-transition Jacobians for robotic dynamics.
- Live Simulation Model Recompilation - Updates an active model and its simulation state without restarting to allow structural changes.
- Model Serialization - Saves compiled model specifications as human-readable XML files or strings.
- Dynamic Geometry Models - Creates 3D strings with wrapping and via-point constraints to simulate mechanical coupling and pulleys.
- Nonlinear Optimization Solvers - MuJoCo solves sequential quadratic programs using a nonlinear least squares optimizer.
- Parallel Computation Thread Pools - MuJoCo creates a thread pool with a specified number of worker threads to parallelize simulation computations.
- Nonlinear Force Models - Specifies nonlinear stiffness and damping for joints and tendons using polynomials.
- Robot Model Composition - Provides the ability to inject subtrees of bodies from one model asset into another to reuse complex robot components.
- Robotic Sensor Simulations - MuJoCo measures scalar and vector data from actuators and joints to provide real-time feedback.
- Simulation Interest Sites - Defines specific locations on bodies to serve as mounting points for sensors or tendon via-points.
- Synthetic Sensor Simulation - MuJoCo generates readings from touch, IMU, force-torque, and rangefinder sensors.
- Tendon and Cable Simulations - Simulates cables by creating paths that wrap around obstacle geometries and pass through specific sites.
- State Snapshots - Stores tensor values of the simulator state at intervals to capture and reconstruct motion.
- Execution Pipelines - Organizes simulation logic into an execution pipeline that can be reconfigured via flags and callbacks.
- Runtime Parameter Tuning - Updates real-valued parameters of a compiled model at runtime to change physics behavior without recompilation.
- Physics - Executes custom control logic at the latest possible point in the simulation pipeline for real-time state access.
- Simulation Engine Plugins - Installs Python or native C callbacks as plugins to modify the computation pipeline for custom components.
- Offscreen Framebuffer Managers - Outputs visual data to a headless framebuffer for synthetic computer vision in cloud environments.
- USD Physics Exporters - Converts physics simulation assets into Universal Scene Description format using a Python-based exporter.
