How to create a ros2 node written in c++ to co-simulate with webots？？

[SenHe524]

I am trying to create a ros2 node written in c++ to co-emulate with webots. Although I have checked a lot of materials, I still have no success. I wonder if the official can write relevant tutorials?

[ygoumaz]

You can create your own package for your simulations and own plugins (in C++ and Python) to extend the interface between the package and Webots. There are tutorials located in the wiki to help you:

• Creating-a-Custom-Package
• Creating-a-Custom-C++-Plugin

I am not sure to understand what your exact needs are, but in case you are looking for a more simpler node that processes data, publishes and subscribes to existing topics, you can take a look at the following tutorial on the official ROS 2 documentation: https://docs.ros.org/en/foxy/Tutorials/Beginner-Client-Libraries/Writing-A-Simple-Cpp-Publisher-And-Subscriber.html.

[SenHe524]

You can create your own package for your simulations and own plugins (in C++ and Python) to extend the interface between the package and Webots. There are tutorials located in the wiki to help you:

• Creating-a-Custom-Package
• Creating-a-Custom-C++-Plugin

I am not sure to understand what your exact needs are, but in case you are looking for a more simpler node that processes data, publishes and subscribes to existing topics, you can take a look at the following tutorial on the official ROS 2 documentation: https://docs.ros.org/en/foxy/Tutorials/Beginner-Client-Libraries/Writing-A-Simple-Cpp-Publisher-And-Subscriber.html.

First, thank you for your reply. I have read both of the two links you provided. The first link uses python language, and the webots_ros2 function package used in the second link seems to be out of date, or I don't understand the meaning of the second function package. May I ask if there are more in-depth examples? Thanks!

[ygoumaz]

In my knowledge, there is no other example based on C++.

Concerning the tutorial on the C++ plugin, what exactly do you mean by "out of date"? Is something not working anymore? Could you give a pointer to the part that is deprecated, so I can update it?

[SenHe524]

In my knowledge, there is no other example based on C++.

Concerning the tutorial on the C++ plugin, what exactly do you mean by "out of date"? Is something not working anymore? Could you give a pointer to the part that is deprecated, so I can update it?

I tried the second linked tutorial and it reported the error shown in the image

[ygoumaz]

You are right, the tutorial was broken when we switched the controller API from C++ to C in webots_ros2_driver (#508).

I will fix it and let you know once it is done.

[SenHe524]

You are right, the tutorial was broken when we switched the controller API from C++ to C in webots_ros2_driver (#508).

I will fix it and let you know once it is done.

Ok, thank you very much. Since I am in a hurry to implement the function shown in the problem, would you mind telling me an approximate repair time, or could you give a routine under the current code framework?

[ygoumaz]

This is it, the tutorial is now up-to-date and fixed. I also added additional information to make it clearer. Don't hesitate if you have any additional suggestions. Since #508, it is not possible anymore to use the C++ API from plugins. Exclusively the C API should now be used.

[SenHe524]

This is it, the tutorial is now up-to-date and fixed. I also added additional information to make it clearer. Don't hesitate if you have any additional suggestions. Since #508, it is not possible anymore to use the C++ API from plugins. Exclusively the C API should now be used.

Oh, thank you very much. I will follow the tutorial and try to write my own code. If there is any problem, I hope to wait for your help. Thank you again.

[omichel]

I assume we can now close this issue. Feel free to re-open it if needed.