SkeletonModificationStack3D stops working when made unique and local to scene.

[Anthony-CamembearGames]

Godot version

v4.0.beta3.official [01ae26d]

System information

Windows 10, Vulkan

Issue description

Hi,

I am having problems with procedural IK movement and I think I have managed to pinpoint the problem to a bug on SkeletonModificationStack3D.

I made a Spider with 4 procedurally animated legs following the tutorial here: https://youtu.be/Ezo3YVKM8Xo

Each leg has a Unique SkeletonModificationStack3D. If I then add one Spider to a scene it works as intended, but when I add a Second Spider the first Spider stops working normally. Its legs now follow the SkeletonModificationStack3D of the second Spider.

If I make the SkeletonModificationStack3D on the legs Local to Scene they still work as intended for the second Spider but stop working for the first one.

Thanks for all the great work on Godot :)

Steps to reproduce

To see this issue in the Example Project open the test_scene.tscn and :

• If you move the red Spider around in the editor its legs work as intended but it also moves two of the legs of the blue spider (the ones whose SkeletonModificationStack3D was not made local to scene)
• If you move the blue Spider around in the editor two of its legs act weirdly (the ones whose SkeletonModificationStack3D was not made local to scene) while the two other don't move.

Minimal reproduction project

https://github.com/Anthony-MostlyHarmless/Test_Godot_Procedural_IK

Test_Godot_Procedural_IK.zip

[TokageItLab]

Closed by #63588.