GPU usage increases considerably only enabling 2D particles turbulence

[canepazzo77]

Godot version

4.x

System information

Windows 10, RTX 3070

Issue description

Using 2D particles when enabling turbulence GPU usage increases dramatically.

Without Turbulence:

With Turbulence:

Steps to reproduce

Add GPUParticles2D, add particle process material and enable turbulence

Minimal reproduction project

see steps

[and-rad]

By how much is it increasing, exactly? This looks like less than a millisecond, which isn't great but sounds about right to me.

[canepazzo77]

By how much is it increasing, exactly? This looks like less than a millisecond, which isn't great but sounds about right to me.

Every Particles node increase it about 0.4ms

[Zireael07]

IIRC turbulence uses noise, and IIRC 3d noise at that, which isn't free - 0.4ms sounds just about in the right ballpark

[canepazzo77]

ah, ok, I thouht an increase of 0,4ms for each node was much

[and-rad]

So, should this be closed? We can always argue whether 0.4ms is a "considerable" increase for adding a bunch of noise lookups in a shader, but I'm inclined to file this under "works as expected". Texture lookups aren't cheap.

[canepazzo77]

Yes

[Calinou]

I remember seeing this being reported elsewhere, but I can't find it right now. Either way, 0.4 mspf on a RTX 3070 isn't a huge increase for something that you'll probably use with a few particle systems at once on screen at most. (Turbulence is not something you should enable on every particle system after all.)

This may be improved by #64606, although its main focus is making it more flexible. Feel free to test that PR locally 🙂

[canepazzo77]

0.4 mspf on a RTX 3070 isn't a huge increase

But on mobile is that high? Because I wanted to use them in a mobile game

This may be improved by #64606, although its main focus is making it more flexible. Feel free to test that PR locally 🙂

I will try it

[and-rad]

On mobile everything is high. Turbulence might not even work on mobile platforms at all, at least not in the Compatibility renderer. Have you ever exported and tested your project on a mobile device yet?

[canepazzo77]

Nevermind, I tried, it make the game crash