Rain effect far away

[Pierre_Bultingaire]

Hello,

In my 2.15.1 project I'm using the rain particles node provided in the weather add-on (and I have it attached to my camera) but I have a problem :
I don't have the feeling that there is rain far away when the emitter is enable, maybe because my emitter size is too small (currently box 100 * 100 * 60), I tried to extend it but to keep a good amount of particles I need to increase a lot the spawn rate, which cause huge FPS loss so that's not a good solution.
I would also like to also if it is possible to hide only some particles from the emitter, in my case the one that are really close to the camera.
Do you have any suggestion, other solution or a parameter that I missed?

Thanks,
Pierre

[silent]

Hi Pierre,

Could you please send us couple of screenshots of how your current rain setup looks like and a screenshot or video of what kind of effect you want to achieve (reference)?

Maybe we can suggest you something after.

And could you please clarify which SDK version are you using?

Thanks!

[Pierre_Bultingaire]

Hi Silent,

Here is a video of my current rain

I changed a little bit the size of the emitter, now it's a box 80 * 80 * 40 (placed on the camera) and the spawn rate is 60000.
As we can see top right I have 55fps while I have 140 without the rain and the raindrops are too close to the camera (too big on screen)

I'm using SDK version 2.15.1

I would like something more like this video :
https://youtu.be/bgyqOlii_Cc

Thanks!

Edited November 15, 2022 by Pierre_Bultingaire

[Pierre_Bultingaire]

Hi again,

I did some modifications and I manage to get a result that look like my expectation

Instead of attaching my emitter on the camera, I place it in front of it :
No more close raindrops (the emitter size is smaller than the distance between the emitter and the camera) and better performances because there is less particles (no more rain behind the camera)

 If you still have suggestions i'll take them.

Thanks!
Pierre

[silent]

We do have plans to improve built-in particles behavior and add more settings that would make such rain particles simulations configurations easier. I guess the rough estimations for that is 2.17 release.

At this time (in 2.15.1) I think you can continue to experiment with existing approach with emitter near the camera and adjust it size & position. For example, you can make it smaller - 20x20m and place camera with slight offset to the back:

Regarding the big particles near the camera, the only efficient way to achieve this is to adjust near clipping size (make it bigger), so it would cut the nearest big particles.

[gr7.76]

@Pierre_Bultingaire Looking at the youtube video you sent, this looks like a thin curtain with many particles, very close to each other, an differing slightly in color and/or transparency to give the illusion of distance. Maybe you can keep the amount of particles you have, but make the emitter box thinner (in the camera direction). Combine this with a few splashes particles (rain particles and splashes particles do not have to match), SSR and even maybe a rain ripple effect on the ground and the illusion could be good enough  (see https://www.danielcoding.com/RainRipples/ for an example)

There are a few great publications on rain effects: AMD's Natalya Tatarchuk - GDC06 and  https://seblagarde.wordpress.com/2012/12/27/water-drop-2a-dynamic-rain-and-its-effects/ but they may go too far :D