Add configurationOverride Plugin

[lrapetti]

Accordingly to what discussed in #392, with this PR I am adding a plugin that enables to modify the value of properties of another plugin attached to the same model.

The plugin was initially thought to set the initial position of a model from a world or from a wrapping model, without the need of generating multiple sdf with the same model just to change some parameters (e.g. icub and icub_standup).

The details on the use of the plugin are contained in the README.MD.

[traversaro]

Can you bump the patch version ( https://github.com/robotology/gazebo-yarp-plugins/blob/master/CMakeLists.txt#L11 ) to 101? See https://github.com/robotology/yarp/blob/master/.github/CONTRIBUTING.md#example for the rationale.

[traversaro]

I know that the existing plugin are already quite verbose in their output, but to be honest I am not a big fan of also adding this: the loading of complex models such as iCub are already quite verbose (to the point that if an error occurs is almost impossible to catch it) and this will make the situation even works. @lrapetti what do you think?

[lrapetti]

If we imagine using the plugin to change the initial configuration for all the control boards, I agree it would be better avoid having those yInfo(). I can remove it.

[traversaro]

That is indeed how it will be used in models such as icub_on_chair. It can also be made optional based on some option, but the important thing for me is that it is not on by default.

[lrapetti]

I will just remove them, I don't think it's worth to add special cases with the print option.

[traversaro]

Just a minor comment, good to go for me. Waiting for @gabrielenava feedback on the docs.

[traversaro]

Minor: Note that gazebo-yarp-plugins is completly independent from icub-gazedo or icub-models, so perhaps is is more clear if you explicitly say start the sentence as : "e.g. If you are using the icub gazebo model from icub-models, and you want to change the <initialConfiguration> etc etc" .

[lrapetti]

Right, thanks! I have changed the sentence and rebased

[gabrielenava]

I tested the plugin for the icub on seesaw and icub standup models. In particular, these models were previously loaded by means of a Gazebo world file defined as follows:

<?xml version="1.0"?>
<sdf version="1.4">
  <world name="default">

    <!-- Light -->
    <include>
      <uri>model://sun</uri>
    </include>

    <!-- Ground Plane -->
    <include>
      <uri>model://ground_plane</uri>
    </include>

    <!-- Seesaw -->
    <include>
        <uri>model://seesaw</uri>
    </include>

    <!-- iCub above the seesaw -->
    <include>
    <uri>model://icub_on_seesaw</uri>
    </include>

  </world>
</sdf>

Where the icub_on_seesaw model was a duplicate of the original icub_no_hands model, with a different joints configuration. I modified the worlds files as follows:

<?xml version="1.0"?>
<sdf version="1.4">
  <world name="default">

    <!-- Light -->
    <include>
      <uri>model://sun</uri>
    </include>

    <!-- Ground Plane -->
    <include>
      <uri>model://ground_plane</uri>
    </include>

    <!-- Seesaw -->
    <include>
        <uri>model://seesaw</uri>
    </include>

    <!-- iCub above the seesaw -->
    <model name="iCub">
      <plugin name='torso_configuration_override' filename='libgazebo_yarp_configurationoverride.so'>
        <yarpPluginConfigurationOverride plugin_name='controlboard_torso'> </yarpPluginConfigurationOverride>
        <initialConfiguration> 0 0 0.0824</initialConfiguration>
      </plugin>
      <plugin name='larm_configuration_override' filename='libgazebo_yarp_configurationoverride.so'>
        <yarpPluginConfigurationOverride plugin_name='controlboard_left_arm_no_arm'> </yarpPluginConfigurationOverride>
        <initialConfiguration>-0.6278 0.5231 0.0010 0.8727 0 0 0</initialConfiguration>
      </plugin>
      <plugin name='rarm_configuration_override' filename='libgazebo_yarp_configurationoverride.so'>
        <yarpPluginConfigurationOverride plugin_name='controlboard_right_arm_no_arm'> </yarpPluginConfigurationOverride>
        <initialConfiguration>-0.6278 0.5231 0.0010 0.8727 0 0 0</initialConfiguration>
      </plugin>
      <plugin name='lleg_configuration_override' filename='libgazebo_yarp_configurationoverride.so'>
        <yarpPluginConfigurationOverride plugin_name='controlboard_left_leg'> </yarpPluginConfigurationOverride>
        <initialConfiguration>0.2094 0.0873 0 -0.1745 0.0479 -0.0898</initialConfiguration>
      </plugin>
      <plugin name='rleg_configuration_override' filename='libgazebo_yarp_configurationoverride.so'>
        <yarpPluginConfigurationOverride plugin_name='controlboard_right_leg'> </yarpPluginConfigurationOverride>
        <initialConfiguration>0.2094 0.0873 0 -0.1745 0.0479 -0.0898</initialConfiguration>
      </plugin>
      <include>
        <uri>model://icub</uri>
        <pose>-0.05 0 0.6926 0 0 3.14</pose>
      </include>
    </model>

  </world>
</sdf>

Now, the model loaded in the world file is the original icub_no_hands model, and the configuration is overwritten by means of the ConfigurationOverride plugin. I also removed the icub_on_seesaw model from the models folder. I did the same procedure for icub_on_a_chair.

I tested the plugin on Gazebo. To be sure I was not using anymore the previous configuration I removed my INSTALL folder and I installed the iCub models again. Here are the results of running Gazebo + icub seesaw/standup world file:

So the plugin is working fine. I created a devel branch in icub-gazebo-wholebody as requested in this issue.

[traversaro]

Thanks @lrapetti and @gabrielenava . This is a feature that deserves some recognition, we do not mantain a changelog for gazebo-yarp-plugins unfortunatly (any volunteer for doing that is highly welcome : ) ) but we should remember to mention this when we will announce the next release.

[lrapetti]

Great! Thanks @gabrielenava and @traversaro