Documentation example scenes available?

[hmercado]

Hello,

I am trying to get surface tension and droplet break up similar to the render examples in the documentation but it seems those scene settings had also time scale set to something other than the default 1 and maybe scene scale too.
Are those scene available to study or can you share the rest of the scene settings besides the surface tension and droplet breakup?

Thank you.

[Svetlin.Nikolov]

Hey, absolutely, here you go: https://drive.google.com/open?id=1YS...HJCzvwP1Y5_UK4

Please ping me if you have any issues accessing.

Cheers!

[hmercado]

Thank you so much Svetlin

Cheers!

[hmercado]

Hello again Svetlin

I think something is not quiet right..
Just opened the scene and hit simulate but the result I got is totally different from the render in the docs



Please check attached preview
SurfaceTensionWithDropBreakUp.zip

[Svetlin.Nikolov]

Dang, now I remember we changed the Surface Tension algorithm a couple of years back. These scenes are nearly 4 years old, made with the early Phoenix 3 versions...

[hmercado]

Wow

So when we refer to the docs for settings we are actually looking at stuff that may have changed a long time ago and so we'll never get the expected results

[Svetlin.Nikolov]

"Never" is a bit strongly put Our content guys will get this example scene to look like it did then. Since the scenes were never meant for sharing, I think it's expected that some will change - the software changes after all.

[Svetlin.Nikolov]

Meanwhile, since the scene did not provide an answer, is there a specific behavior you are looking to get in your setup? Also, if it's urgent, I will delay coding something and will help set up the scene?

[hmercado]

Thank you,

Well is not urgent really at the moment, its just personal studies trying to recreate some real world reference.

I was having difficulties getting good surface tension and droplets 'cause no matter what setting combination I tried nothing was turning out as good looking as the rendered examples in the docs.
I thought maybe some other scene settings not shown in the docs example where having an effect.
Now I know why

I guess I will keep experimenting with settings and hopefully nail the sim and get a good enough result closer to my real life reference.

Please do let me know if/when the examples are updated to have similar or even better results as they had before

Thanks!

[Svetlin.Nikolov]

Roger that, I hope we'll have good news these next few days. This is gonna be a good time to tidy all these scenes and put them up for download on the docs site. Specifically for the Surface Tension, I'm looking at my change that went into Phoenix 3.12 where the algorithm became so strong I decreased the effect of the option in the Dynamic rollout 7 times, but maybe I decreased it too much. So looks like by increasing the Surface Tension value the scene will start working like before that change, but gotta run a few sims...

[Svetlin.Nikolov]

Okay, so far looks like the opposite - I didn't overdo the surface tension strength option decrease - it actually is still too strong; To get results comparable to pre-3.12 Phoenix, you gotta decrease the Surface Tension 6-7 more times; Now running the middle sim (that says Breakup 0.5, Tension 0.5) at Surface Tension 0.07 and it's looking similar. Maybe should be something between 0.05 - 0.09... We are still running sims to find out

[hmercado]

Oh
I had it looking closer to the example by dropping the sphere in 10 frames instead of 20

Will try with the smaller values then

[Svetlin.Nikolov]

Hah, nice Also looks like you gotta decrease the Droplet Radius with about 50% - it was 3 in the original scene and now at 2 looks more like it. Since it's an new algorithm, it's possible that it can't be matched to the pixel. Actually in the docs video you can see what the problem with the old algorithm was - the central column of liquid start getting this diamond shape on the top. Before the change, if you left droplets float in zero gravity with the old algorithm, they gradually turned into diamond shapes instead of spheres...

[hmercado]

This may be an entire different topic but...
Is it possible that a low time scale value is also affecting how gravity works on the fluid?
'Cause playing with that scene and trying different values I noticed that at lower time scale there is an apparent lower gravity effect or almost complete lack of gravity.

[Svetlin.Nikolov]

Oh, interesting! Do you have a saved scene where this happens?