Visualizing the CAT Vehicle

The goal of this tutorial is to see the CAT Vehicle through the gazebo client. You will also become familiarized with how to interact with the gazebo client, including noting whether your simulation is running "in real time" or not.

Begin by loading the catvehicle_skidpan.launch file with roslaunch. Don't forget that in this tab (and any others you create) to source the devel/setup.bash file

Open a new tab:

You should be able to see the vehicle in 3D.

Using your mouse, you can zoom in and out to see more (or less) of the scene. There are some important things to note:

• the big giant blue thing -- this is the laser sensor's sweep.
  • You can disable the sensor by passing a command-line parameter of front_laser_points:=false when you launch the simulator, or by duplicating the launchfile into your own package and editing it
  • You can have the sensor still operator, but not be visually displayed, if you edit the catvehicle.gazebo file (search for front_laser_link and the visualize element of the XML file).
• "Real Time Factor" -- Depending on how powerful your machine is, you will have an RTF close to 1.00. This means that it takes 1.0 second of wall-clock time to simulate 1 second of time in gazebo. If you cannot run at real-time, your RTF will drop (e.g., an RTF of 0.8 means that it takes 1.0 seconds to simulate 0.8 seconds of time in gazebo).

We're now ready to progress to visualizing the individual sensors. To do this, we will use rviz, instead of gzclient, to visualize the vehicle.

azcar_sim (deprecated)

The below instructions are for v1 of the simulator, which is now deprecated.

The goal of this tutorial is to see the CAT Vehicle through the gazebo client. You will also become familiarized with how to interact with the gazebo client, including noting whether your simulation is running "in real time" or not.

Begin by loading the azcar_skidpan.launch file with roslaunch. Don't forget that in this tab (and any others you create) to source the devel/setup.bash file

Open a new tab:

You should be able to see the vehicle in 3D (see photo). Using your mouse, you can zoom in and out to see more (or less) of the scene. There are some important things to note:

• the big giant blue thing -- this is the laser sensor's sweep. You can turn this off by editing the src/azcar_sim/urdf/azcar_slipping.gazebo file (search for front_laser_link and the visualize element of the XML file).
• "Real Time Factor" -- Depending on how powerful your laptop is, you will havea an RTF close to 1.00. This means that it takes 1.0 second of wall-clock time to simulate 1 second of time in gazebo. If you cannot run at real-time, your RTF will drop (e.g., an RTF of 0.8 means that it takes 1.0 seconds to simulate 0.8 seconds of time in gazebo).

We're now ready to progress to visualizing the individual sensors. To do this, we will use rviz, instead of gzclient, to visualize the vehicle.