This repository is a work I conducted to try and combine the strengh of both extended position based dynamics (xpdb) and a jit-compiled physics simulator (brax).
To install xpdb_brax from source, clone this repo, cd to it, and then:
python3 -m venv env
source env/bin/activate
pip install --upgrade pip
pip install -e .
Xpdb_brax is a rigid-body simulator that integrates dynamics using a Euler scheme. It solves constrains iterativly using Gauss-Newton and sub-stepping.
Its accurate integration of the physics allows it to simulate the djanibekov effect. Look at the way the box flips from time to time around its z-axis.
An other interesting effect it can simulate out of the box is the precession effect of a spinning wheel.
Xpdb_brax currently support ball joints and revolute joints but it can be extended to support any kind of constrain.
