Slow rendering on : webgpu_compute_particles

[Makio64]

Description

On iphone12 pro max it seems the "webgpu_compute_particles" is very slow, I originally though its the computation, but it's actually the particule rendering:

• Webgpu safari, top angle : 60fps
• Webgpu safari, bottom angle : 20fps

I'm a bit surprised cause I though render 1M particles would have been a piece of cake in webgpu.

For the moment I can do a PR :

• to setup 256k particles on mobiles by default
• add a gui to select the number and regenerate the particles system.
• pause/play the physics

So it might help to monitoring the performance on various mobile

Reproduction steps

1. open the example on mobile
2. play with the camera angle

Code

X

Live example

X

Screenshots

X

Version

r172

Device

Mobile

Browser

Safari

OS

iOS

[Mugen87]

I'm a bit surprised cause I though render 1M particles would have been a piece of cake in webgpu.

When an application is fragment shader bound, using WebGPU won't help.

I do not vote to introduce mobile specific presets in the examples since that will only complicate things. As a quick fix, we could lowering the particle count to 500000 which should noticeably improve the performance and the example will still look good.

[Makio64]

I think it add just a fews lines to dispose and recreate the buffer ( or reallocate ) and call the computeInit again once the user select the number desired ?

[Mugen87]

If we start doing this in webgpu_compute_particles, it's fair to ask doing it in all other compute examples which I'd like to avoid. Let's try to keep things as simple as possible.