Support recreating model entities

[iche033]

🎉 New feature

Summary

This PR adds support for recreating model entities. This feature is implemented to for the model editor work. Once a user makes changes to a model, i.e. by updating its or components or it's child entities' components, the idea is to just delete the old model and create a new one. This avoids having to go to different systems, detect what changed, and apply updates.

It introduces a new components::Recreate component. When attached to an model entity, the SimulationRunner will mark the existing model (recursively) as removed and recreate a new model by cloning from the original one. The cloned / recreated model will have the same name but different Entity Ids.

Test it

Added a INTEGRATION_recreate_entities test

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

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[nkoenig]

Does the integration test pass for you? I'm getting failures:

[Err] [EntityComponentManager.cc:431] Requested to clone entity [5] with a name of [box_link], but another entity already has this name.
[Err] [EntityComponentManager.cc:552] Cloning child entity [5] failed.
[Err] [EntityComponentManager.cc:431] Requested to clone entity [9] with a name of [cylinder_link], but another entity already has this name.
[Err] [EntityComponentManager.cc:552] Cloning child entity [9] failed.
[Err] [EntityComponentManager.cc:431] Requested to clone entity [13] with a name of [sphere_link], but another entity already has this name.
[Err] [EntityComponentManager.cc:552] Cloning child entity [13] failed.
[Err] [EntityComponentManager.cc:431] Requested to clone entity [17] with a name of [capsule_link], but another entity already has this name.
[Err] [EntityComponentManager.cc:552] Cloning child entity [17] failed.
[Err] [EntityComponentManager.cc:431] Requested to clone entity [21] with a name of [ellipsoid_link], but another entity already has this name.
[Err] [EntityComponentManager.cc:552] Cloning child entity [21] failed.
/home/nkoenig/work/ignition/fortress/ign-gazebo/test/integration/recreate_entities.cc:134: Failure
Expected equality of these values:
  24u
    Which is: 24
  ecm->EntityCount()
    Which is: 4

[iche033]

Does the integration test pass for you? I'm getting failures:

fixed in 39a1d34

[iche033]

nice, I was able to recreate a model with sensors in the links.

When I tried to recreate a rendering sensor, e.g. rgbd camera, I get an error msg that the camera already exists. This should be fixed by 8a6552e and gazebosim/gz-sensors#169

[nkoenig]

I'll merge this once CI looks okay.

[mjcarroll]

Out of curiosity, did you try this on any models with joints? If not, I can.

[nkoenig]

Oh I did not try this on a model with joints.

[mjcarroll]

Just did a simple test world with two double pendulums here: https://github.com/ignitionrobotics/ign-gazebo/tree/recreate_entities_joints

I'm getting errors like

[Err] [EntityComponentManager.cc:1982] Error: attempted to clone links, but link [14] was never cloned.
[Err] [EntityComponentManager.cc:388] Error updating the cloned parent link name for cloned joint [92]
[Err] [EntityComponentManager.cc:1982] Error: attempted to clone links, but link [9] was never cloned.
[Err] [EntityComponentManager.cc:388] Error updating the cloned parent link name for cloned joint [91]

[nkoenig]

Just did a simple test world with two double pendulums here: https://github.com/ignitionrobotics/ign-gazebo/tree/recreate_entities_joints

I'm getting errors like

[Err] [EntityComponentManager.cc:1982] Error: attempted to clone links, but link [14] was never cloned.
[Err] [EntityComponentManager.cc:388] Error updating the cloned parent link name for cloned joint [92]
[Err] [EntityComponentManager.cc:1982] Error: attempted to clone links, but link [9] was never cloned.
[Err] [EntityComponentManager.cc:388] Error updating the cloned parent link name for cloned joint [91]

Is this something you are looking into, or should I take it on?

[mjcarroll]

I'm looking into it. It reliably happens when I have two double pendulums that are cloned, but not if there is a single model in the world.

[mjcarroll]

@nkoenig see #1206