====== Robot Operating System (ROS) ======

===== On Linux =====

Follow [[http://wiki.ros.org/ROS/Installation]].
We will use ROS Kinetic in the course, nevertheless, ROS Melodic should mostly be compatible.

You can also use the [[http://ptak.felk.cvut.cz/tradr/share/ros-kinetic-desktop-full.simg|Singularity image]] provided for labs, or modify the [[http://ptak.felk.cvut.cz/tradr/share/ros-kinetic-desktop-full.txt|Singularity recipe]] to build your custom image.
===== On Windows =====

  * Ubuntu in [[https://www.virtualbox.org/|VirtualBox]]
  * Via [[https://en.wikipedia.org/wiki/Windows_Subsystem_for_Linux|Windows Subsystem for Linux (WSL)]], see [[http://wiki.ros.org/Installation/Windows]]
    * Expect the support to be only partial as WSL have some limitations.
    * Use ROS Melodic with Ubuntu 18.04 or ROS Kinetic with Ubuntu 16.04. ROS installation instructions for Linux shoud work once you are in the Ubuntu Bash shell.
    * For applications with graphical output (e.g., RViz), you will need:
      * Running X Server for Windows (e.g., [[https://sourceforge.net/projects/xming/|XMing]])
      * Target X display specified (usually '':0'') when running graphical applications:\\ ''DIPLAY=:0 rosrun rviz rviz''
      * You can add it to ''~/.bashrc'' for it to stay in effect:\\ ''echo 'export DISPLAY=:0' > ~/.bashrc''
  * Dual boot with Ubuntu

===== At Labs =====

At [[https://cyber.felk.cvut.cz/study/computer-labs/|labs]] (e.g., E130, E132), Robot Operating System (ROS) is available through [[https://en.wikipedia.org/wiki/Singularity_(software)|Singularity]] containers.
For Ubuntu 16.04 + ROS Kinetic, run:\\
''singularity shell %%--%%nv /opt/ros-kinetic-desktop-full.simg''\\
(''%%--%%nv'' is needed for graphical output, e.g. RViz)

Then a catkin workspace has to be sourced, e.g. the system one:\\
''source /opt/ros/kinetic/setup.bash''\\
or your own workspace:\\
''source ~/workspace/aro/devel/setup.bash''

All images from Docker Hub are available too, e.g.:\\
''singularity shell %%--%%nv docker:%%//%%ros:kinetic-robot-xenial''\\
''singularity shell %%--%%nv docker:%%//%%ros:melodic-robot-bionic''\\
Note however that the images are quite large and download to your home (with limited space) by default:
So one may need to switch the cache directory somewhere else, e.g.:\\
''mkdir -p /tmp/$USER/singularity''\\
''ln -s /tmp/$USER/singularity ~/.singularity''
===== On GPU Servers =====

There are [[https://cyber.felk.cvut.cz/cs/study/gpu-servers/|GPU servers]] available via remote access (''ssh'').
Log in via one of these commands (use your faculty username):\\
''ssh -X username@cantor.felk.cvut.cz''\\
''ssh -X username@taylor.felk.cvut.cz''\\
Singularity images may also be located under ''/local/singularity_images''.
You can follow, more or less, the [[courses:aro:tutorials:ros#at_labs|instructions for labs]] once you are there.

Also, please read [[https://cyber.felk.cvut.cz/cs/study/gpu-servers/|the instructions]] on GPU usage.
Most notably, use at most one GPU at once.
Select GPU to use via environmental variable ''CUDA_VISIBLE_DEVICES'', e.g.\\
''CUDA_VISIBLE_DEVICES=2 my_command''\\
Prevent using any if you don't need it:\\
''CUDA_VISIBLE_DEVICES= my_command''\\
You can export it to stay in effect for all the following commands:\\
''export CUDA_VISIBLE_DEVICES=2''\\
''my_command''