Setting a 3D node as top_level with physics interpolation on make it interpolate from its old local transform

[TheMagnat]

Tested versions

• Reproducible in: 4.5.beta1

System information

Godot v4.5.beta1 - Windows 11 (build 22631) - Multi-window, 2 monitors - Vulkan (Forward+) - dedicated AMD Radeon RX 6950 XT (Advanced Micro Devices, Inc.; 32.0.21013.1000) - 13th Gen Intel(R) Core(TM) i5-13600KF (20 threads) - 31.84 GiB memory

Issue description

Setting a 3D node as top_level while having the physics interpolation on will make it interpolate from its old local tranform to its now transform (this is my assumption)

Note: This happen with the new scene traversal algorithm and with the legacy one

20250628-1838-30.4435941.mp4

Steps to reproduce

• Set a 3D node that have a parent node with have some transformations as top_level during runtime

Minimal reproduction project (MRP)

PhysicsInterpolationTopLevelBug_MRP.zip
(just run the scene node_3d.tscn)

[lawnjelly]

Setting toplevel effectively is changing the transform (under the hood), so you need to call reset_physics_interpolation() after the call:
https://docs.godotengine.org/en/stable/tutorials/physics/interpolation/physics_interpolation_quick_start_guide.html

This is probably not obvious to users, so I'll take a look at whether we can either add an auto-reset here though to make life easier, or add it to the docs. 👍