Adds support for ocean currents

[arjo129]

Signed-off-by: Arjo Chakravarty arjo@openrobotics.org

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🎉 New feature

Closes #

Summary

Adds support for ocean currents to the hydrodynamics plugin. It also adds an optional support for namespaces.

The behaviour of the <namespace> parameters is described as follows:

  ///   <namespace> - This allows the robot to have an individual namespace for
  ///     current. This is useful when you have multiple vehicles in different
  ///     locations and you wish to control the currents of each vehicle
  ///     separately. If no namespace is given then the plugin listens on
  ///     the `/ocean_current` topic for a `Vector3d` message. Otherwise it
  ///     listens on `/model/{namespace name}/ocean_current`.[String, Optional]

Test it

To test run:

ign gazebo auv_controls.sdf

And apply a really strong current:

ign topic -t /ocean_current -m ignition.msgs.Vector3d -p 'x: 10, y:0, z:0'

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge

[caguero]

I added very minor tweaks in 20b57f9.

[caguero]

My main suggestion is to also support the ability to set the current via SDF. This way, we'll cover the most common use case without having to send any additional messages. Remember to document the extra parameter as well.

[arjo129]

I've added a <defaultCurrent> field.

  ///   <defaultCurrent> - A generic current.
  ///      [vector3d m/s, optional, default = [0,0,0]m/s]

[caguero]

Very minor request, other than that looks good.

[mabelzhang]

Nits.

[mabelzhang]

CI looks passing. I think Windows is disabled (thanks to the awesome new CI documentation in ignitionrobotics/docs/ci.md!), and the failing tests on Mac I've seen before. The push test is complaining about PERFORMANCE_each, which... should be okay?

I haven't tried the PR itself, but we should probably add some integration tests next time (if it's possible to test with some known numbers?), to make sure we don't break stuff with new features.

(I will try it in Fortress once it's forward ported 😅 I don't have a local Edifice build at the moment.)

[arjo129]

DCO won't let me merge. @caguero I think you need to sign the last commit.