When and why to use flip solver?

[ben_hamburg]

Hi there,

I didn´t really have the time to try out the new flip solver in the new nightly build, so before I do, I was wondering if you could shed some light on when and why to use the flip solver over the standard solver?
I´m pretty sure this must have been asked before, but skipping through the forum I couldn´t find anything.
Also I don´t really know what the name of the "old" solver is...
And also, just to get it clear: Flip solver is only for fluid sims, right?

Cheers,

Sam

[Ivaylo Katev]

yes, the flip is only for liquids, btw technically the word fluid includes the gasses too. the situations when the old core will produce better result are very low in count. in general in all the scenes involving closeup liquids, like milk splash, chocolate, pouring glass with liquid etc, are harder to do with the old core. the main reason is the grid artifacts, but not only them. the splash looks significantly better in the flip solver, i mean the natural splash, not the dedicated particle group. the old core is grid based, it's actually a solver for fire, not for liquids. long time the liquids were considered a side application, that was not a good idea.

[ben_hamburg]

long time the liquids were considered a side application, that was not a good idea.

haha, yeah, thats what you get, if you give us something that can do fluids, that doesn´t come with the hefty pricetag of all other fluid apps out there!
Also I think a lot of small shops or freelancers have to deal with liquid stuff of some sort at some point, while explosions aren´t coming along as often...

But that is good to hear, that I probably do´t have to worry about where and when to use which solver. So I should probably just get used to using the flip solver (also I think there is not much to "get used to" anyway), seems like you are pretty far at implementing it completely anyways, as far as I can tell.

[Ivaylo Katev]

actually we are planing to separate the front end simulator objects for fire/smoke and liquid, and the liquid one will use only the flip solver. of course the legacy simulator will be kept for some special cases.

[ben_hamburg]

Ah , great, I think that totally makes sense! As always. Keep up the great work!

[Christian Haas]

Hi Ivaylo,
a few weeks ago you uploaded your 3 waterfall flip solver test on vimeo, is it possible to get those files as starting point, please ? Would be really great, thank you and best regards

chris

[Ivaylo Katev]

well, int's only one file simulated with different setups. the scene is part from production of Paul Oblomov, better ask him for permission.
i think in the description of the movies are briefly described the most important settings.

[ANIMATIK_BT]

Hello. I`ve installed the latest nightly build phoenixFD_adv_22000_max2016_vray_30_x64_26285 with hope to play with the flip solver but cant find any switch or anything with "flip" in the name. So, where do I find it? Also I have noticed that the conservation parameter disappeared from dynamic panel, is it somewhere elese now? ( I didn`t upgrade for quite some time.. )

[Ivaylo Katev]

for now the advection method parameter contains this option, in few days separate object will appear in the geometry/phoenix section

[ANIMATIK_BT]

Ok, and what about flip solver?

[Ivaylo Katev]

i'm speaking exactly about how to enable it

[ANIMATIK_BT]

Oh, I`m sorry, I thought you were talking about the conservation thing. Unfortunatelly there is no advection parameter either. Is it possible it has been removed from the latest build?

[Ivaylo Katev]

well, apparently you are using latest build and this is the UI of the new object, separated liquid simulator, it's flip by nature, no need to be set. but as i know it's still not working properly, use the legacy simulator (PHXSimulator) instead and the above mentioned method to switch to flip mode

[ANIMATIK_BT]

Ok, that explains a lot I will play around with that. Thank you Ivaylo.