MPEG-SD anchoring extension

[Etiennefaivredarcier]

This pull request brings the implementation of the MPEG_Anchor extension (link) along with a few bugfixes and reworks on the interactivity extension.

The extension implement:

• The support for trackables
  • Including these types:
    • Floor
    • Viewer
    • Plane
    • 2D Marker
    • Marker geo
    • Application
• The support for anchors

For this pull request to be working properly and to be able to test it, a version of Unity-player is needed, as well as the new version of rt-xr-content.

This extensions offers a lot of core fonctionnalities for AR, has been tested on a Android mobile phone and comes with the following dependencies versions: For Unity version 2022.3, most of the following packages are installed via the global AR Package from Unity. Here is the complete list:

• ARCore Extensions - 1.40.0 - com.google.ar.core.arfoundation.extensions
• Apple ARKit XR Plugin - 5.1.1 - com.unity.xr.arkit
• AR Foundation - 5.1.1 - com.unity.xr.arfoundation
• Google ARCore XR Plugin - 5.1.1 - com.unity.xr.arcore
• OpenXR Plugin - 1.9.1 - com.unity.xr.openxr
• XRCore Utilities - 5.3.0 - com.unity.xr.core-utils
• XR Interaction Subsystems - 2.3.0 - com.unity.xr.interactionsubsystems
• XR Legacy Input Helpers - 2.1.10 - com.unity.xr.legacyinputhelpers
• XR Plugin Management - 4.4.0 - com.unity.xr.management

[nlsdvl]

You might want to add these new dependencies to the package.json manifest as well.

[nlsdvl]

@Etiennefaivredarcier Thank you for contributing the AR anchoring.

I started reviewing your contribution, and I ran into issues related to com.google.ar.core.arfoundation.extensions giving me this fatal error:

Assembly 'Packages/com.google.ar.core.arfoundation.extensions/Editor/ExternalDependencyManager/Editor/Google.IOSResolver.dll' will not be loaded due to errors:
Unable to resolve reference 'UnityEditor.iOS.Extensions.Xcode'. Is the assembly missing or incompatible with the current platform?
Reference validation can be disabled in the Plugin Inspector.

The only way I found to resolve this is by patching com.google.ar.core.arfoundation.extensions or installing the iOS build environment even if these are currently unused.
Do you also have this bug on your side ?

After fixing this error, I get a lot of warnings in Unity's editor console :

• variables that are declared but unused in the contribution
• variables that are not initialized
• unreachable code
• potential null dereference

can you please fix these ? One reason to keep the log clean is to keep an eye on the warnings we don't have control over, such as the one comming from dependencies about deprecated components. The warnings might not show up when you open the project, in that case they should show up when building.

[Etiennefaivredarcier]

Hello @nlsdvl ,

Thank you for your comments, i've commited a new version with the fixes. Concerning the com.google.ar.core.arfoundation.extensions, I have the problem as well since I don't have the iOs build. What I recommend for this package is either to remove the iOsResolver dll from the project if it is not useful. I found the link to the issue here for reference:
google-ar/arcore-unity-extensions#172

[nlsdvl]

@Etiennefaivredarcier regarding the iOsResolver dll error.
The steps to resolve the issue must be documented in the player build steps.
I ended up installing the iOS build kit.

However the project now only compiles for Android because of the dependency on ARCore.
Windows build no longer works.

[nlsdvl]

@Etiennefaivredarcier I can now build for Android but the Windows build is still broken

[nlsdvl]

Hi @Etiennefaivredarcier - As discussed offline, I tested your contribution using the supporting content from https://github.com/5G-MAG/rt-xr-content/tree/rt-xr/dev/mpeg_anchoring - I observed that anchoring didn't work as I expected. Display of the nodes or scenes can be triggered by the application when the appropriate trackable is detected in the environment, but the node is not always anchored.