Gazebo

Installation

Automatically installed after following the ROS installation instructions.

Make sure after you install it you source the setup.sh file in the .bashrc script:

source /usr/share/gazebo-7/setup.sh

Also source any setup.bash scripts that are in your projects:

source /home/febbo/.julia/v0.6/MAVs/workspace/devel/setup.bash

Also in the setup.sh file in the usr/share/gazebo-7/ directory, add to the resource path if you need to as:

export GAZEBO_RESOURCE_PATH=/usr/share/gazebo-7:/usr/share/gazebo_models:/usr/share/gazebo-7/worlds${GAZEBO_RESOURCE_PATH}

In the above example we also added the /worlds folder.

Note

Using the gui to create models is limited because the default full version of ros kinetic does not let you edit the models after you save them. So, then I started to learn how to make the models directly using XML. The only way to get around this is to build from source but then you won;t be able to use any ROS Ubuntu package related to Gazebo from the ROS deb repo.

From source (option A)

Follow these instructions

Additional notes:

  • Step 1:

    To get the Gazebo-8 stable branch:

    /opt$ sudo hg clone https://bitbucket.org/osrf/gazebo /opt/gazebo -b gazebo8

    To get the Gazebo-7 stable branch:

    /opt$ sudo hg clone https://bitbucket.org/osrf/gazebo /opt/gazebo -b gazebo7

sudo hg clone https://bitbucket.org/osrf/gazebo /tmp/gazebo -b gazebo7

  • Step 3:

    Configure Gazebo:

    sudo mkdir build
cd build
sudo cmake ../

    Build Gazebo:

    /opt/gazebo/build$ sudo make -j4

    Install Gazebo:

    sudo make install

  • Step 4:

    Set up environmental variables and

From source (option B) -preferred for Gazebo-7

http://gazebosim.org/tutorials?tut=install_dependencies_from_source

Potential Issue

Note

If not sourced properly:

febbo@febbo-HP-ZBook-17-G2:~$ gazebo
gazebo: error while loading shared libraries: libgazebo_common.so.7: cannot open shared object file: No such file or directory

Then try:

febbo@febbo-HP-ZBook-17-G2:~$ find / -name 'libgazebo_common.so.7' 2>/dev/null
/usr/local/lib/libgazebo_common.so.7
/tmp/gazebo/build/gazebo/common/libgazebo_common.so.7

And updated the /etc/bash.bashrc file appropriately:

gksu gedit /etc/bash.bashrc

By adding (in this case):

export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH

Note

when trying to start Gazebo from the command line:

gazebo: error while loading shared libraries: libsdformat.so.5: cannot open shared object file: No such file or directory

Terminology

  1. Xacro:

(Xaxro) (XML macros) an XML macro language useful for shorter robot descriptions.

  • xacro:include: import content from another file
  • property: define constants ${property_name}
  • xacro:macro: include the file where the macro is and call it using the macro’s name and filling in the required values
  1. SDFormat
An XML format that describes environments for robot simulators visualizations and controls. Originally part of Gazebo but now is stable enough that it stands alone.

Basics

Model Structure

Make sure that the model is structured correctly. An issue that was ran into is described here where I tried to put a model in a lower level directory. Models need to go just below catkin/src/, then setup.sh must be modifed as:

export GAZEBO_MODEL_PATH=/usr/share/gazebo-7/models:/home/febbo/catkin_ws/src/:${GAZEBO_MODEL_PATH}

Model State Info

Using rospy to get the model states.

World Files

Note

When saving a world file, put it into the folder with the other world files!

Useful Software