Skip to main content
Pre-release

This release is a pre-release and may not be stable for production use.

JAXsim

A scalable physics engine implemented with JAX. With JIT batteries 🔋

⚠ This project is still experimental, APIs could change without notice. ️⚠

⚠ This simulator currently focuses on locomotion applications. Only contacts with ground are supported. ️⚠

Features

  • Physics engine in reduced coordinates implemented with JAX in Python.
  • Supported JIT compilation of Python code for increased performance.
  • Transparent support to execute the simulation on CPUs, GPUs, and TPUs.
  • Possibility to run parallel multi-body simulations on hardware accelerators for significantly increased throughput.
  • Support of SDF models (and, upon conversion, URDF models).
  • Collision detection between bodies and uneven ground surface.
  • Continuous soft contacts model with no friction cone approximations.
  • Full support of inertial properties of bodies.
  • Revolute, prismatic, and fixed joints support.
  • Integrators: forward Euler, semi-implicit Euler, Runge-Kutta 4.
  • High-level classes to compute multi-body dynamics quantities from simulation state.
  • High-level classes supporting both object-oriented and functional programming.
  • Optional validation of JAX pytrees to prevent JIT re-compilation.

Planned features:

  • Reinforcement Learning module developed in JAX.
  • Finalization of differentiable physics through the simulation.

Installation

You can install the project with pypa/pip, preferably in a virtual environment:

pip install jaxsim

Have a look to setup.cfg for a complete list of optional dependencies. You can install all of them by specifying jaxsim[all].

Note: if you need GPU support, please follow the official installation instruction of JAX.

Credits

The physics module of JAXsim is based on the theory of the Rigid Body Dynamics Algorithms book authored by Roy Featherstone. We structured part of our logic following its accompanying code. The physics engine is developed entirely in Python using JAX.

The inspiration of developing JAXsim stems from google/brax. Here below we summarize the differences between the projects:

  • JAXsim simulates multibody dynamics in reduced coordinates, while brax uses maximal coordinates.
  • The rigid body algorithms used in JAXsim allow to efficiently compute quantities based on the Euler-Poincarè formulation of the equations of motion, necessary for model-based robotics research.
  • JAXsim supports SDF (and, indirectly, URDF) models, under the assumption that the model is described with the recent Pose Frame Semantics.
  • Contrarily to brax, JAXsim only supports collision detection between bodies and a compliant ground surface.
  • While supported thanks to the usage of JAX, differentiating through the simulator has not yet been studied.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Citing

@software{ferigo_jaxsim_2022,
  author = {Diego Ferigo and Silvio Traversaro and Daniele Pucci},
  title = {{JAXsim}: A Physics Engine in Reduced Coordinates for Control and Robot Learning},
  url = {http://github.com/ami-iit/jaxsin},
  year = {2022},
}

Maintainers

@diegoferigo

License

BSD3

Metadata

Release files for jaxsim 0.1.dev164

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for jaxsim 0.1.dev164
File Size Uploaded
jaxsim-0.1.dev164.tar.gz 57.0 kB Details

Built distribution (wheel)

Table of built distributions (wheels) for jaxsim 0.1.dev164
File Interpreter ABI Platform
jaxsim-0.1.dev164-py3-none-any.whl Python 3 none any Details

Total release size: 126.8 kB

Release files / jaxsim-0.1.dev164.tar.gz

Download URL jaxsim-0.1.dev164.tar.gz
Size 57.0 kB
Tags Source
SHA-256 checksum
How to use checksums
30151e96e13d93121faeabf6b748aa0db2a4c2875611157a19e62393f2c7c04a
BLAKE2b-256 checksum
How to use checksums
c495b170270c74dda107db41254556141f355d19f9bcef2dbd5fb6bf927cfe5b
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/4.0.1 CPython/3.11.4

Release files / jaxsim-0.1.dev164-py3-none-any.whl

Download URL jaxsim-0.1.dev164-py3-none-any.whl
Size 69.8 kB
Tags Python 3
SHA-256 checksum
How to use checksums
af6ae043f218a8ca84c356c65e6c5d2e33f4c56f05d5be9e037d2a7def5597b5
BLAKE2b-256 checksum
How to use checksums
f65473514b8d2cf298da890cc6b87ffe9097137100ad37d838ab181d9dee5966
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/4.0.1 CPython/3.11.4

Release history Release notifications | RSS feed

0.9.0

2 release files

0.8.2

2 release files

0.8.1

2 release files

0.8.0

2 release files

0.7.0

2 release files

0.6.1

2 release files

0.6.0

2 release files

0.5.0

2 release files

0.4.2

2 release files

0.4.1

2 release files

0.4.0

2 release files

0.3.0

2 release files

0.2.0

2 release files

0.1

2 release files

This release

0.1.dev164 This release

2 release files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page