what is the problem here???

[tsetso]

It seems that the particle count is too low.
Since you're using the FLIP solver, try increasing the "Rate" parameter of the foam first. This will generate more bubbles.
Also if they are mainly under the water, increase the "Rise speed", it'll force them to reach the surface of the water faster.

To achieve a result similar to the photo on the left, you'll need both patterns and b2b.
Also keep in mind that the size of the bubbles plays important role the to b2b - if they are too small, they won't stick, no matter how high the b2b is set to.
The patterns and b2b, however, are features designed to work with the Classic sovler. They can be used with the FLIP solver also, but I'm not sure how it behaves.

[themaxxer]

ok what take out of your answers, first hank you... when bubbles are to small they didn't stick together, good to know. second the flip solver isn't ready to be used with all parameters. then i again use the classic advection. i will try to rise the rise speed more... in this case more than the fall speed... maybe rise 120... fall 100.
the flip solver gives a much more detailed and nicher mesh. i dan't do the same with classic advection.

[tsetso]

You got me right!
And yes, the FLIP solver produces much more detailed meshes, but it's still in the process of developing, so not everything is polished and ready to be used.

[themaxxer]

ok thank you, then i can simulate and simulate like hell not getting it right then i have to wait until flip is ready. in the mean time i try classic advection.

[themaxxer]

new problem with classic advection... what is that now? can you help. i have to finish this project.

[Ivaylo Katev]

as i understand, you are creating a river, that has relatively high dynamics and this makes the foam to mix with the water. your reference seems to be a settled water, that allows the foam to rise on the surface. can you describe what you are trying to do, i think it should be possible with the flip. of course not all options are supported yet, but i think all that you need is already available.

[themaxxer]

i solved the problem i posted yesterday... it was the animated emitter... emitting particles. i had to animate it further away.

but i faced a new issue wich showed up already a few times when i use classic advection. disaappearing fluid. you can see it int the picture below i am at frame 800 and the fluid disappears. before there were more fluid. where does it go?

[themaxxer]

maybe you are right ivaylo my river scene is very dynamic. maybe i have to rethink it and model spots where the fluid can settle. i would like to have everything, splashes, mice foam patterns, underwater foam, motion blur.

[Ivaylo Katev]

the classic advection really can cause disappearing (or false appearing) of the liquid, the usual solution is increasing of the spf. if you need flat liquid surface and foam over it, you really need places where the liquid can settle.

[themaxxer]

ok, thanks, i will increase the spf and remodel spots where the fluid can settle.

[Ivaylo Katev]

i think it's better to return to the flip. the particles hurled by the water will be fixed before you will be able to setup good simulation with the classic advection

[themaxxer]

ok, that's a word. when can i expect the update then.

[Ivaylo Katev]

hopefully the tomorrows nightly will be fixed, if we succeed to represent the bug

[themaxxer]

ok, cool... i hope we both speak about the same problem? that flip causes splashes to explode and bounce? here i send you a pic that rendered 15 hours, with way to much foam and bounces... i wanted to try a final situation. for a animation wich is my goal i have to look again at the river tutorial and tweak mx parameters. to avoid flickering maybe i render with brute force and no second bounce. for lighting i use a hdri.

[Ivaylo Katev]

yes, i think we are speaking about the same thing, the straight lines of splash appearing suddenly from nothing. the reason is single liquid particle suddenly accelerated to very high velocity and leaving track of splash particles. i was able to reproduce the bug with your scene. tried to reproduce it in a light scene created from scratch, but without success, now will see what can i do investigating your scene