Skeleton3D mesh is not visible for the first frame [4.2-dev2 or later]

[nathanfranke]

Tested versions

Seems to be a regression between 4.2-dev1 and 4.2-dev2 starting at PR #78988

git checkout 2c8cbcd1a025f7211db87bca4c9c3cdec2ef6eab # good
git checkout e8df8c5e2c067edfbe5ca448e4ba1c266f653843 # bad

Reproducible in

• 4.5-dev1
• 4.4.1-stable
• 4.3-stable
• 4.2-dev2

Not reproducible in

• 4.2-dev1
• 4.1.4-stable
• 4.0.4-stable

System information

Arch Linux x86_64, 6.13.8-arch1-1 on x11

Issue description

Video showing the player model briefly flashing invisible after input

2025-03-30_11-45-29.mp4

I cannot reproduce with Skeleton2D in 4.4.1-stable with this setup:

1. Official Skeleton2D Demo

2. in player.gd, disable animation tree on ready

3. enable "autoplay on load" for "idle" in AnimationPlayer

4. add this debug script anywhere:

   func _input(event: InputEvent) -> void:
   	if event.is_pressed() and not event.is_echo():
   		get_tree().reload_current_scene()

5. launch, press any key to reload, and the Skeleton2D remains visible

Steps to reproduce

1. Launch MRP
2. Press any key or click the mouse
3. You can see the model disappear for ~1 frame

Minimal reproduction project (MRP)

Based on the platformer 3d demo. It only has a glb, tscn, and a simple script.

platformer-3d-demo.zip