Skeleton3D pos/rot/scl issue when blending animations via animation blend tree

[macryc]

Godot version

Godot 4 alpha 5

System information

Win10, RTX2070

Issue description

I originally raised this issue a few months ago under: #55838.

It was recently closed in #57675

But the issue still remains. The problem is that the 3d skeleton's root bone becomes skewed in all 3 aspects: position, rotation, scale when blending between 2 skeletal animations using the animation blend tree.

The recent merge fixes only the position, while scaling and rotation issues remain.

The only commit so far that fixes the issue properly is this one:
https://github.com/godotengine/godot/pull/54205/commits

Steps to reproduce

See original issue here: #55838

Minimal reproduction project

No response

[TokageItLab]

@macryc Is the rest of root bone of your model Transform3D(Quaternion(0,0,0,1),Vector3(0,0,0))? I need a sample project to determine the cause.

[macryc]

Hi guys, please close this issue. Upon further inspection, it's not the Blend2/3 node that is causing issues anymore. It's the Add2/3 node now.
I've raised another bug report for this - #59536