Simulating shaking bottle foam

[jonnybefree]

Hi there,

i've a tight deadline here where i have to simulate foam inside a bottle wich is shaking.
you don't see the liquid moving, only the bubbles.
could you give me a hint maybe what is the fastest way to reaching there?
for now i used the bottle as cutter geometry with volume inject, and initial fill up. But the foam sprays around all over, and wan't stay inside the bottle..
any hints maybe?

thanks a lot in advance and best regards

Jonas

[Svetlin.Nikolov]

Hey,

There is an issue currently with particles penetrating geometry walls. I'm looking at that right now and will let you know when you can get a nightly with the fix.

Thanks!

[jonnybefree]

thanks Svetlin.
Is the above described method the one to go btw? Or is there another smarter way?

[Svetlin.Nikolov]

Sounds like you are filling the entire simulator half-way with liquid and rendering only the inside of the bottle. I guess this might work, but you need to shell the bottle so that the particles don't penetrate it. This would make it not usable as a cutter and you need to have another geometry - e.g. the non-shelled version as a render cutter. Another thing I maybe don't understand correctly is the Volume Inject - are you using the bottle itself as an emitter or another geometry? If the bottle has to use volume inject, then it can't be solid, but this means it cannot hold the liquid inside it either.

[jonnybefree]

ja you're right, but i don't get it..
When i use initial fill up, and the bottle as cutter, the foam simulation want be correct no?
so do i have to fill the bottle by simulation, and use it for the foam generation?
or how would you go on that?

[Svetlin.Nikolov]

Remember that the cutter is just a render option - it won't affect how the fluid is simulated in any way. You could either:
- Shell the bottle, make the bottle solid, keep the initial fillup, and use another object on the inside to produce any initial foam particles as well. You need to keep a copy of the original bottle shape, make it non-solid and not renderable and set it as render cutter.
- Shell the bottle, make it solid, and use a third object inside the bottle in non-solid mode to volume brush both liquid and particles inside the bottle. Before the particles penetrating walls bug is fixed, you might also have to use a render cutter in order to filter out any escaping particles, but after this is fixed you won't need that.

Hope this helps

[jonnybefree]

ja Helps a lot. Thanks a lot Svetlin!

[jonnybefree]

hmm i try'd it, but he's emitting the foam on surface only..

[Ivaylo Katev]

my suggestion:
- bind the grid to the bottle, this is the most important part, without this, you will newer get rid of the penetrating particles!
- enable the foam birth
- create the fill up object (dummy cylinder)
- animate the bottle movement
- simulate

[jonnybefree]

Hi Ivaylo, this is what i've done so far without luck..
could i maybe drop you a little scene for taking a look into it?

[Svetlin.Nikolov]

Sure, you may drop it to Support and the guys will have a look.

Thanks!

[jonnybefree]

ah never mind.
Deadline was today, so i switched to PF in that case. thanks anyway for your help!

Best regards
Jonas