Liquid Life Span

[dj_buckley]

I'm currently in the process of faking a small waterfall effect. I'm also still new to Phoenix and trying to learn as and when it's required. Is there a simple way of controlling the life span of liquid? For example in the screenshot, I want the "jet" to continually emit liquid, but I want to be able to control when the bits in red die off. At the minute the bits in red will just keep moving around until I stop the simulation, but I want them to ultimately fade out naturally and die. How do I do this? I just want to some small localized splashes and foam and mist where the jet of water meets the surface below it. In an ideal world and if I had the time/patience, the solid surface below would also be water and part of the simulation.

[georgi.zhekov]

Hey,

You can create a Particle Tuner node and use the age of the Liquid particles as a condition to delete them.

Here is a video that shows how this works - https://docs.chaos.com/display/PHX4M...eParticleTuner

In the video we show how to delete particles that are moving fast and are older than 0.5s, but in your case you can use only the age condition.

You can find more about the Particle Tuner here - https://docs.chaos.com/display/PHX4MAX/Particle+Tuner

Hope this helps!

[dj_buckley]

Perfet, exactly what I was after, thanks Georgi

[dj_buckley]

Having a couple more issues with this, I'm trying to get subtle splashes/mist/foam just at the point of impact where the falling liquid meets the stationary water surface.

I'm finding a few things - I can't control the size of the splash/mist particles and currently they look way too big.

I don't know how to have the splash/mist only happen at the point of impact.

Separately, my entire simulation disappears if I take the resolution of the grid too high? When I press simulate it just doesn't show any liquid or anything.

[georgi.zhekov]

The size of the splashes/mist is determined by the grid resolution - the higher the grid resolution the smaller the splashes will be. Since increasing the grid resolution is not always the best approach as it changes the simulation results and also increases simulation time, you can change the size of the splashes during render time by lower the size multiplier in the Particle Shader node that renders the splashes/mist.

In order to determine when splashes/mist will be born you will need to adjust the splashes birth threshold and the mist options in the Splashes rollout.

You can find more about how different particle types are born/dying here - https://docs.chaos.com/display/PHX4M...heading-Splash

If the grid res is too high you probably run out of memory - if you open the Phoenix log (usually located in C:\ChaosPhoenix ) there should be an error that you don't have enough memory for the sim.

[dj_buckley]

Thanks Georgi, I doubt i'm running out of memory, I've got 192GB DDR5 RAM and it's only a small sim, the grid resolution was 44 million when it started disappearing, I moved the emitter geometry and it started appearing again. Strange.

Thanks for the other tips, i look into those

[georgi.zhekov]

Hmm, if it didn't emit anything and moving the emitter fixed it - probably the emitter was way too small for this grid resolution.

[dj_buckley]

Hi I want to reignite this thread as I want to take the sim further. I ultimately want the waterfall to interact with the water below (swimming pool) so that I get natural splashes and ripples etc. The biggest issue I have is the pool itself. Normally when doing pools without water features I just use a simple plane with the PhoenixFDOcean Texture in the displace slot. But now I want to take it further. I've tried numerous different techniques based around Initial Fill, but whenever I simulate the pool water seems to compress a lot. This makes it very diffuclt to have a very specific pool water level. The main pool water should be 6" below the pool deck/edge tiles. It needs to stay there whilst also interacting with the water fall. How can I precisely set the water level and avoid the pool water compressing and sloshing around everywhere when I simulate it? Imagine it's first thing in the morning, the pool surface is perfectly calm, then you turn the water fall on, this water 'state' seems impossible to recreate (with my very limited Phoenix knowledge at least)

[zdravko_pavlov1]

Hello. Have you tried to use Fill Up for Ocean option for the Initial Fill Up? This will help the water to stay at the level you want. It is important to have all of the container walls set to Open in order for the Fill Up for Ocean to work properly.
https://gyazo.com/4f3ef14a97725147223d602f100e1270
And also, here's a video that might help you with some ideas:
https://www.youtube.com/watch?v=_ZP1-GUaDvY

[dj_buckley]

That video is excellent, an absolute gold mine and answers a lot of other questions I've had previously. I don't suppose the source files will be made available for it?

[zdravko_pavlov1]

Sure, why not. I'll search for the scene file and upload it first thing in the morning.

[dj_buckley]

I managed to get the pool water and waterfall interacting but it just keeps filling up and the 'jet' is way to strong so it creates huge splashes. How would I control this? In your gif, the initial fill stays at the same level and doesn't keep filling?

[zdravko_pavlov1]

Does your current setup use the Fill Up for Ocean? If it does you don't need the pool geometry.

[dj_buckley]

This is the actual geometry that I'll be using, I was just setting up a smaller test scene with that first one, the pool slopes and has steps so I've created some dummy geometry using the pool walls and just selected 'Initial Fill Up' on the Phoenix Properties

[dj_buckley]

Those screenshots also show where the water level needs to be, exactly where the blue tiles meet the grey edge tiles