visualise splash/foam emission areas

[harvr]

Hi

as topic says, is there a way to visualise the emission areas for splash and foam? currently seems like u have to try settings then sim, then change, would be nice if we could get a rough idea of emission areas.
unless i'm missing something

cheers

Harv

[Svetlin.Nikolov]

Not sure how this would work, since you have to have at least half the other fluid particles simulating in order to determine where new ones would be born, and this adds up every frame. Here you can see what I mean - foam and splash can be born in several different ways: https://docs.chaosgroup.com/display/...les+Life+Cycle. In short, it's still going to require simulation in order to find out where these particles will be born, which defies the idea.

[harvr]

Hi Svetlin,

i understand that would be an issue with the "sim everything at once" workflow, but what about in a , "sim fluid first", then "sim foam/splash" second workflow?
If u have fluid already sim'd, can u not then "see" the ares of splash/foam generation?
Houdini does a similar thing, once the fluid is sim'd, you can visualise ares of generation on that particular frame, obviously this doesn't take into account "build up" over frames, but it works quite well to give rough idea of where foam/splash will be born

cheers
harv

[Svetlin.Nikolov]

Yup, this is easy, but would it be useful if you need to simulate the whole thing once anyway?

[Paul Oblomov]

In h it is like volume representation of areas, where emitting starts. And feels it is like visualizing areas in phx with high.... I don't know... internal vorticity or speed probability. Also, woult be great to have h foam "density contol" and erosion, to form nice geometry clean foam patterns, without crazy single particles. In h I ended up forming very nice and life-like foam structures. For now, phx foam feels very dissolated, without kind of a domain feeling...

Here's the stock image what I'm talking about. Foam looks like a bunch of connected domains with strong inner forces (maybe b2b dunno). I can't get the same with phx no matter what I do, tho I thought phx foam was superior to h (before h17.5). Would be great to have tutorial how to make that foam. Maybe I'm missing some vital options...

https://thumbs.dreamstime.com/z/blue...-100487033.jpg

[harvr]

i agree with Paul about the density control and erosion.
Also i think H uses repellents to create the "empty" areas of foam too. Maybe similar to what PHX is doing , not sure, but they have a fair amount of control over these. In PHX we just have size and strength for foam pattern.

Also on the other point of visualisation Svetlin, i think it would be a useful addition, i tend to get my fluid behaviour the way i like it first, then add foam/splash afterwards. So a visualiser would be nice, as i'm typing, i am however trying out "all in one" sims, i kinda like the idea of the liquid and splash interchanging "states" so to speak.

While i'm at it, my current project required a deep container, it would have been nice to have narrow band, would have saved my millions of fluid particles

thanks for your time Svetlin

Harv

[Paul Oblomov]

Quite interesting to see - does picture I was refereeing to achievable with new phx ? Without lots of useless single particle foam. In h it is one click thing.

[Svetlin.Nikolov]

Why not? You've had Fog mode in the particle shader for over 10 years.

Also, please show me a video of that 1 hour single click

[Paul Oblomov]

Heh, it is not about fog Density control looks very natural, tho doesn't use b2b. If I show you - will you show me phx result, to compare

[Svetlin.Nikolov]

Please feel challenged to create a great simulation in Phoenix and share it.

[Paul Oblomov]

My main complaint with phoenix foam is that phoenix does not try to connect single foam particles into a piece of foam, but leaves them disconnected as single pixel dots. Houdini via density control is just trying to do that, which in my opinion makes the foam more realistic, since I've never seen single-pixel foam in real life. So, all my attempts to make the beachwaves pretty close to cam - just won't work, as the phoenix just can't do that. Everything looks like a huge number of dots, even like a noise. I'd have to have a supercomputer for sure to make it look anything like reality. I would love to discuss this, but feels like you guys are doing another very important stuff.

P.S. Maybe this is why, you still don't have any tutorial, covering such case. And also you guys kept silent to my questions, about pixar short Piper...

[Svetlin.Nikolov]

Now this is a constructive comment and we are going somewhere Yes, the single particles can be removed at simulation or filtered at render time - this is already something I have in mind.

[Paul Oblomov]

... or connected in realistic way Or at least like in H.

[Svetlin.Nikolov]

Realistic way. Noted.

[threedguy]

Totally agree with Paul's point (oh, the irony : the isolatad foam particles don't add to realism, more the contrary (especially in animations they are a source of noise).
Some form of filtering/clustering makes sense and would be very desirable!