In previous lessons we encountered with the simulated world. We understood how to move in it, change the camera view. In this lesson we will learn how to choose a world for simulation, create a new world, edit the existing world.
Specifying World for Simulation
We use following command to run the Gazebo world:
roslaunch is an important tool that manages the start and stop of ROS processes.
Many ROS packages come with launch files, which you can run with:
In this command:
turtlebot_gazebo is a package name and
turtle_world.launch is a launch file.
We can specify which world we want to use with argument
You can find existing world files in this folder
Try to run
You will see this world:
The default world is in the environment variable
You can see it running this command:
You can update it:
1. For current terminal run this command:
2. For all new terminals run this command:
It will work after relaunching the terminals.
Launching an Empty World
1. Create a folder for new worlds:
2. Launch an empty world:
3. You will see:
Editing a World
You can add simple shapes objects and objects from model database.
1. Select the
NOTE: You can see
Connecting to model database. It might take a long
time to connect to Gazebo’s model database.
You will see this picture after connecting:
2. Add a box.
Select the box icon, then move your mouse onto the render window. Left click when you choose the proper position of the box.
3. Add a sphere and a cylinder.
4. Add a bookshelf.
Insert tab to access the model database. Select the bookshelf. Add
it to the render window.
NOTE: It might take some time to download a model from Gazebo’s model database.
5. Add a cafe table and a dumpster.
You should have something similar to this picture:
You can see on the picture how to modify the pose of each model.
6. Model may be deleted by right-clicking on a model and selecting
Delete the dumpster.
Saving a New World
File menu and choose
Save World As.
A pop-up will appear asking you to choose a folder and enter a new filename.
turtlebot_custom_gazebo_worlds folder and type
In terminal press
Ctrl+C. Now you can launch your world:
You can watch these steps in this video:
In the next lessons we will use this command:
with the default world
Or we will specify the world file in the command: