ParticleProcessMaterial ignores the value set for particle_flag_damping_as_friction

[cherriesandmochi]

Godot version

v4.2.beta3.official [e8d57af]

System information

Godot v4.2.beta3 - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 960 (NVIDIA; 31.0.15.3623) - Intel(R) Core(TM) i5-4690 CPU @ 3.50GHz (4 Threads)

Issue description

ParticleProcessMaterial will always generate a shader that uses the realistic friction formula for damping, wheter 'particle_flag_damping_as_friction' has been enabled or not.
It's pretty safe to assume that the bug got introduced with #79527.
Additionally, the check for that very flag seems to be inverted:

godot/scene/resources/particle_process_material.cpp

Line 961 in 09946f7

if (!particle_flags[PARTICLE_FLAG_DAMPING_AS_FRICTION]) {

Steps to reproduce

• Create a GPUParticles3D node.
• Assign a new ParticleProcessMaterial to 'process_material'.
• Convert the ParticleProcessMaterial to a ShaderMaterial
• Open the shader and go to line 300 to see the "realistic friction" code, which shouldn't have been generated, as 'particle_flag_damping_as_friction' is disabled by default.

Minimal reproduction project

N/A

[akien-mga]

CC @QbieShay

[QbieShay]

Regression from https://github.com/godotengine/godot/pull/83831/files

[cherriesandmochi]

I don't think #84028 closes this issue.
Sorry, I probably wasn't very clear in my report, but the else-branch never gets taken, resulting in the same shader being generated, no matter the value set for 'particle_flag_damping_as_friction'.
I think I should have opened 2 separate issues.

particle_flag_damping_as_friction = false

particle_flag_damping_as_friction = true

[QbieShay]

I also opened #84029

Could you verify if it changes by reloading the scene?

[cherriesandmochi]

Reloading the scene and then converting the particle materials into shader materials will still result in identical code, albeit the opposite branch:

[QbieShay]

Then the two PR i created yesterday should address this issue 👍