The most minimal hello world with gnuplot visualization!!! stackoverflow.com/questions/11175694/bullet-physics-simplest-collision-example/36987063#36987063

Figure 1.
gnuplot plot of the y position of a sphere bouncing on a plane simulated in Bullet Physics
. Source. From: What is the simplest collision example possible in a Bullet Physics simulation?

Bullet Physics parallel execution (Bullet Physics GPU acceleration)

0 0

Does not seem to support it unfortunately:

2015 thread: pybullet.org/Bullet/phpBB3/viewtopic.php?t=10783. On the reply pybullet.org/Bullet/phpBB3/viewtopic.php?p=36197&sid=5fbceed0c3a5ebcf233d328bb4ee1342#p36197 Erwin Coumans says there's no support, and no support planned.

pyBullet

0 0

Python library for Bullet Physics.

Became very popular as of result of people using Bullet Physics for reinforcement learning AI training robot simulations.

Website: pybullet.org/

Source code: somewhere inside the main Bullet Physics source tree. Yay.

Erwin Coumans (Bullet Physics main author)

0 0

MuJoCo (2015-)

0 0

github.com/deepmind/mujoco

Was a closed source project by "Roboti LLC", which was then acquired by DeepMind in October 2021 and open sourced March 2022: www.deepmind.com/blog/open-sourcing-mujoco

This library is quite cool. Feel very brutally lean and mean.

MuJoCo getting started

0 0

Tested on Ubuntu 23.10;

git clone https://github.com/google-deepmind/mujoco
cd mujoco
git checkout 5d46c39529819d1b31249e249ca399f306a108ac
mkdir -p build
cd build
cmake ..
make -j

Now let's play. Minimal interactive UI simulation of a simple MJCF scene with one falling cube:

bin/basic ../doc/_static/hello.xml

Test soure code: github.com/google-deepmind/mujoco/blob/5d46c39529819d1b31249e249ca399f306a108ac/sample/basic.cc. The only thing you can do is rotate the scene with the computer mouse it seems. Mentioned at: mujoco.readthedocs.io/en/2.2.2/programming.html#sabasic

Some more interesting models can be found under the model/ directory: github.com/google-deepmind/mujoco/tree/5d46c39529819d1b31249e249ca399f306a108ac/model E.g. the imaginary humanoid robot DeepMind used in many demos can be seen with:

bin/basic ../model/humanoid/humanoid.xml

A more advanced UI with a few controls:

bin/simulate ../doc/_static/hello.xml

Test soure code: github.com/google-deepmind/mujoco/tree/5d46c39529819d1b31249e249ca399f306a108ac/simulate. Mentioned at: mujoco.readthedocs.io/en/2.2.2/programming.html#sasimulate

A very cool thing about that UI is that you can manually control joints. There are no joints in the hello.xml, but e.g. with the humanoid model:

bin/simulate ../model/humanoid/humanoid.xml

under "Control" you move each joint of the robot separately which is quite cool.

Video 1.

Demo of MuJoCo's built-in simulate viewer by Yuval Tassa (2019)

Source.

There's also a bin/record test executable that presumably renders the simulation directly to a file:

bin/record ../doc/_static/hello.xml 5 60 rgb.out
ffmpeg -f rawvideo -pixel_format rgb24 -video_size 800x800 -framerate 60 -i rgb.out -vf "vflip" video.mp4

Mentioned at: mujoco.readthedocs.io/en/2.2.2/programming.html#sarecord but TODO that produced a broken video, related issues: