Vulkan: GPUParticles3D instantiate gives visual artifacts

[ncollie42]

Godot version

4.0 alpha 15

System information

Fedora x11 NVIDIA GeForce GTX 970

Issue description

instantiating particles occasionally leaves visual artifacts and/or effects shadows for a single frame.

instantiating a lot of GPUParticle3D at once makes it more obvious, bellow I instantiate 20 new GPUParticle3D on the left side every .05 seconds and queue_free after 1 second. Having the same total amount of active emitters running does not give the same artifacts as instancing and freeing.

Screencast.from.09-06-2022.02.27.49.PM.webm

Steps to reproduce

GPUparticle3D.zip

Minimal reproduction project

No response

[Calinou]

Related to #56691 (likely due to the same cause).

[henriquelalves]

Just posting an ugly hack for this issue. Apparently this was fixed in a project I'm working in by restarting the GPUParticles (to delete all current particle geometries), and giving sufficient time between stop emitting particles and deleting the scene.

Ugly code:

func _kill() -> void:
	# This is a fix for the flickering problem of particles: https://github.com/godotengine/godot/issues/65443
	# We have to restart the particles and give sufficent amount of time before deleting the node,
	# so particles won't flicker on the last position they were rendered
	$Bullet/GPUParticles3D.restart()
	$Bullet/GPUParticles3D.emitting = false
	await get_tree().physics_frame
	await get_tree().physics_frame
	await get_tree().physics_frame
	
	queue_free()