Brax Sim Environment with MJX

Official UWRS Repo for MuJoCo Soccer Simulation

System Requirements

• WSL Ubuntu 22.04
• CUDA
• NVIDIA CUDA capable GPU
• Python 3.12

Setup

Make python virtual environment

python3 -m venv .venv

Install requirements.txt

pip install -r requirements.txt

Upgrade JAX package to use CUDA

pip install --upgrade jax[cuda<version>]

Replace with your CUDA version

Visualize

Verify setup by running the visualize.py file

python visualize.py

This will generate a simulation rollout and then display an opencv window with the simulation. A video named output.mp4 will be saved in the root directory.

Troubleshooting

WSL Ubuntu 22.04

If you are using WSL Ubuntu 22.04, you may encounter issues with rendering the simulation:

1) opencv: Could not load the Qt platform plugin "xcb" in "" even though it was found

• To fix this issue be sure to remove any PyQt installations in the python virtual environment
• If the issue persists install the headless version of opencv along with opencv-python

pip install opencv-python-headless

2) Visual artifcats in video such as black bars or flickering

• If you have a NVIDIA GPU WSL may have issues with rendering the simulation. To fix this issue you can export the software openGL environment variable

export LIBGL_ALWAYS_SOFTWARE=1

3) Verifying Display connection from WSL to Host

• If you are using VcXsrv to connect WSL/VM to your host Windows system try the following in the WSL terminal
• Use XLaunch and configure the settings and check the box for Disable Access Control. Then check the Display setting

export DISPLAY=:0

• Use this to verify that the IP address of your display is correct. If 'nameserver:' appears before the IP address - something is incorrectly configured

echo $DISPLAY

• When you're done you should be able to run this default GUI. It should show a window of 3 spinning gears

glxgears