Joint states tutorial

[vatanaksoytezer]

Adds an rrbot model to demos and shows the usage of joint_states plugin.

[ahcorde]

You are adding here the URDF and the SDF and using it both in the launch file. I don't like this approach because if you modify one you must need to modify the other one. You should use only the URDF, with xacro (which is imported but not used) you can convert the URDF and uing it to spawn the model. In this file you can find how to do it.

Another question that I open here it's that the rrbot.urdf should live only in one repository we should not copy this file in every repo that make use of it.

[ahcorde]

You should also sign the PR

[ahcorde]

@vatanaksoytezer, I have seen in your profile that you are working for Picknik maybe we can speed up this other PR ros-simulation/gazebo_ros_demos#41 where I think the rrobot description should live.

[vatanaksoytezer]

@vatanaksoytezer, I have seen in your profile that you are working for Picknik maybe we can speed up this other PR ros-simulation/gazebo_ros_demos#41 where I think the rrobot description should live.

Sure I will ping Dave internally.

[vatanaksoytezer]

Another question that I open here it's that the rrbot.urdf should live only in one repository we should not copy this file in every repo that make use of it.

I would agree that but I really wouldn't want to make ign_gazebo_demos depend to gazebo_ros_demos for rrbot only. Maybe you guys can consider opening up a rrbot description and depend on that?

[vatanaksoytezer]

You are adding here the URDF and the SDF and using it both in the launch file. I don't like this approach because if you modify one you must need to modify the other one. You should use only the URDF, with xacro (which is imported but not used) you can convert the URDF and uing it to spawn the model. In this file you can find how to do it.

@ahcorde Follow up question on this one. Since this is to demonstrate the usage of joint_states plugin in ignition, where should I put the plugin if I don't have the sdf file? I was mostly looking up for @chapulina 's dolly package where she also defines the robot from an sdf file.

[vatanaksoytezer]

Another problem that I just realised is if rrbot_description live somewhere else and contains gazebo and ros2_control stuff that is not compatible with ignition (yet), wouldn't it be problematic?

[vatanaksoytezer]

@ahcorde update:

• Pinged Dave on gazebo PR.
• Signed off the commits and cleaned up stuff, except for the sdf (see my comments above)

[vatanaksoytezer]

Ignore the comments above on sdf, just figured that out. I'll fix in and send updates soon

[vatanaksoytezer]

This should work, but the colors (and I think frictions) are not parsed correctly to ign. If you point me a way I can fix it right away

[ahcorde]

@vatanaksoytezer, I can see the color in ignition

[ahcorde]

LGTM