How to make a droplet splash when it collides with the surface?

[sean_brown]

Hello,

Im trying to build a rain effect with Phoenix but when droplets hit the ground they just land and stick to it. How can I make a single droplet splash? My surface tension and viscosity are all set to 0.

[georgi.zhekov]

Hey

Can you show us your Phoenix settings and the result you're getting at the moment?

Have you enabled the splashes?

Thanks!

[sean_brown]

Hey

Can you show us your Phoenix settings and the result you're getting at the moment?

Have you enabled the splashes?

Thanks!

Hi @georgi.zhekov

Attached are my settings and here is a link to a 4 second render. Im just emitting from a cube with low discharge. I enabled splash like you suggesting but didnt effect the water colliding. only from where its emitting.

https://f.io/liLuH9Y4

[sean_brown]

Adding a 6 screenshot here due to upload limit.

[Svetlin.Nikolov]

Oh yes, you need to enable Wetting under the Liquid rollout and there you have the Sticky Liquids option that would help you.

Also, for small scale liquid simulations, it would be good to have at least some Surface Tension, so you could try raising this a little as well.

Cheers!

[sean_brown]

Oh yes, you need to enable Wetting under the Liquid rollout and there you have the Sticky Liquids option that would help you.

Also, for small scale liquid simulations, it would be good to have at least some Surface Tension, so you could try raising this a little as well.

Cheers!

Hi Svetlin.Nikolov
I tried turning on Wetting and adding .1 surface tension but still couldnt produce splashing after droplets collide with the floor. See my renders bellow. I have also linked to my scene file if you could kindly adjust my settings to create dropplet splashes. When i enable splash/mist, it comes from the emitter, not on the collision.

Scene file:https://f.io/CrR0wpC8

Arnold render with spash/mist
https://f.io/ILe7BrYN

Vray render with splash/mist
https://f.io/pxVHN4tG

Vray render with no splash/mist but with wetting, .1 surface tension and sticky set to 0
https://f.io/ZZbMR-m6

[Svetlin.Nikolov]

Oh, definitely try making your droplets larger - if they are made up of just one liquid particle, then they can't split and create a splash ring when the droplet hits.

Cheers!

[sean_brown]

If it’s larger then it won’t look like rain since rain droplets are small. If Phoenix can’t split such small particles, is there another way to fake the splashes on surfaces separately with a second Phoenix sim?

[Svetlin.Nikolov]

Sure, you could create a second simulator with a very thin layer of liquid over the ground, or this could even be done in a single simulator.

[sean_brown]

Can you tell me how? I’ve been at this for weeks with several tests and have gotten nowhere. I’ve searched the forums and rain seems to be an obscure topic. I’ve tried wetting, splashes and dozens for failed tests. So any step by step would be really helpful right now. Or if you can provide a scene file with a basic setup then I can study that.

[Svetlin.Nikolov]

Ah, check this tutorial for how to fill up the bottom of the grid:

These two tutorials by Gerson Silveira also touch on concepts that would be important for your setup:

Also a couple notes on your scene - definitely reduce the Simulator size and shrink it only around the two planes - the simulation is running super slowly because the simulator is huge.

Also, in order to lower the simulation times, set the Step Per Frame in the Liquid rollout to 1 and raise them only if you really need to - raising the Steps per Frame is needed if the fluid is moving very fast or if there are obstacles or sources in the scene that are moving very fast. With liquids, you could raise the Steps Per Frame to make them smoother or if you want to get a better viscosity effect. Since you don't have viscosity in this setup, raise the Steps per Frame only if the liquid gets dotted, disjointed and rough.

Hope this helps, cheers!