Modeling Virtual Objects

The final task of this project is to model a virtual object with markers in rviz. The virtual object is the one being picked and delivered by the robot, thus it should first appear in its pickup zone, and then in its drop off zone once the robot reaches it.

First, let’s see how markers can be drawn in rviz. Luckily, there’s an official ROS tutorial that teaches you how to do it. The tutorial is an excellent reference and includes a C++ node capable of drawing basic shapes like arrows, cubes, cylinders, and spheres in rviz. You will learn how to define a marker, scale it, define its position and orientation, and finally publish it to rviz. The node included in the tutorial will publish a different shape each second at the same position and orientation. Check out the tutorial and go through the documentation to get started.

You will need to first run this node and visualize the markers in rviz. Then you’ll need to modify the code and publish a single shape example: a cube. Your code should follow this algorithm :

Publish the marker at the pickup zone
Pause 5 seconds
Hide the marker
Pause 5 seconds
Publish the marker at the drop off zone

Later you will be able to combine this node with the pick_objects node coded earlier to simulate the full home service robot.

Modeling Virtual Objects

Task Description:

Follow these steps to create a virtual object in rviz:

Task List:

Create an add_markers package with roscpp and visualization_msgs dependencies

Create an add_markers C++ node

Copy the C++ code and edit the node name to add_markers

Edit the frame_id

Modify the C++ code to publish a single shape as describer earlier

Edit the CMakeLists.txt file and add the executable , and libraries

Build the catkin_ws

Create an add_marker.sh shell script that launches the turtlebot , AMCL , rviz , and your add_markers node.

Launch your shell script and manually add a Marker in rviz

Task Feedback:

Good job building the virtual objects!