Make Video recorder plugin work with MinimalScene

[ahcorde]

Signed-off-by: ahcorde ahcorde@gmail.com

🎉 New feature

Summary

This PR is part of the consolidation between Scene 3D in ign-gazebo and ign-gui. This PR adds a plugin to record the user camera.

It builds on top of #813

Test it

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)
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[ahcorde]

Require: gazebosim/gz-rendering#358

[ahcorde]

@osrf-jenkins retest this please

[ahcorde]

@chapulina open for review

[chapulina]

@ahcorde , for expediency, I pushed some suggestions directly to this branch in 7650dda instead of opening a PR against this branch. In summary:

• Revert changes to gui.config
• Merge VideoRecorderLogic into VideoRecorder like we're doing for TransformControl, with a legacy flag

Feel free to revert any of the changes I pushed as you see fit.

It seem to work for me with both MinimalScene and GzScene3D, but I'd appreciate it if @iche033 gives his ok when he's back. I'm mainly concerned about the extra camera update that we're doing in this plugin.

[codecov]

Codecov Report

Merging #900 (4e7964d) into main (c992f31) will not change coverage.
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[iche033]

It seem to work for me with both MinimalScene and GzScene3D, but I'd appreciate it if @iche033 gives his ok when he's back. I'm mainly concerned about the extra camera update that we're doing in this plugin.

I think we may be able to skip the camera update in this plugin. Given that the render event is emitted after the camera->Update() call in the scene 3d plugin, the image should be ready when the VideoEncoder calls AddFrame in this plugin

[chapulina]

the render event is emitted after the camera->Update() call in the scene 3d plugin

Humm I think we may have a different issue then. Because the MinimalScene is not calling the render event in lockstep with simulation. This makes it hard for this plugin to record in lockstep...

[ahcorde]

@chapulina @iche033 what about adding a new camera in the same position and orientation as the original one ? then we can do whatever we want with this camera, isn't it ?

[chapulina]

what about adding a new camera in the same position and orientation as the original one ?

That's an interesting idea 🤔 The new camera would need to track the original camera. And I imagine we'd have to protect against both cameras rendering at the same time, which I understand is not supported by ign-rendering / Ogre.

[iche033]

what about adding a new camera in the same position and orientation as the original one ?

That's an interesting idea thinking The new camera would need to track the original camera. And I imagine we'd have to protect against both cameras rendering at the same time, which I understand is not supported by ign-rendering / Ogre.

The other option for lockstepping is to spawn the new camera on the server side and do the recording there (instead of the recording from the gui). Maybe that's what you mean? You can probably tweak the camera_video_recorder system with a new option to record from the gui camera instead of a camera sensor. If user indicates to record from the gui camera, the system just creates a new camera with same configuration as the gui camera and tracks the gui camera's pose.

[chapulina]

The new approach of synchronizing Scene3D and the Sensors system that @mjcarroll is thinking of implementing could allow lockstepping the GUI camera when running with --same-process.