Latte Macchiato?

[Ihno]

Hi,
I'm about to start making a Latte Macciato sim.
It needs to look somewhat like this:
https://www.shutterstock.com/de/vide...to-milk-layers
I will have to sim the milk too but you get the idea.
Has anyone ever done something like this before? Or, are there any scenes floating around to start from?

One thing I'm especially wondering about is how to render this? The vraymtl fog still doesn't support 3d mapping right?
I've been thinking about using smoke instead of liquid for the volume.
I guess the sim itself will also be pretty tough though. So I'm happy for any input!

[joconnell]

I'd say do the sim with a fake foam top higher up than the render line of the foam so you get something to keep the smoke in. Have your emitter nozzle below this fake foam line. Do the foam as a separate object and then use the cutter function in the phoenix / vray grid to keep the smoke where you want it.

[Ihno]

Thanks! That's what I'm doing now. Seems to work quite well. But the smoke disappears too early. What can I do to make it keep its volume longer? Will raising the conversion quality help? Or is this more a matter of spf which is 1 right now.

[georgi.zhekov]

Yes, try adding more conservation quality that should help.

[Ihno]

Thanks!
I'm making progress.

The sim looks good but I I need to damp the velocity in the end.
How would I do that? Use the mapper with a black vray-color for the velocity channel?

[georgi.zhekov]

The Mapper is one way of doing it. If you're using Phoenix 4 you can use the Voxel tuner.
You can create a dummy box (set it to be non-renderable and non-solid from the Phoenix properties) and set the Voxel tuner to lower the velocity based on the distance to the box.

[Svetlin.Nikolov]

Onr more note - if you want to damp the velocity everywhere, just drop a Max drag force and make sure its channel list contains the voxels and particles you wanna slow down.

[Ihno]

Interesting! I don't have 4.0 yet. But out of interest, would it open the ability to have a damp min vel. for the damping like the bodyforce has?
Btw. could I use the Bodyforce for this too?
If the simulation inside the body object. And I turn the strength to zero, would the damping be the only thing that's still working?
Or would it change the Simulation in some other ways?
The damp min vel. seems to be very handy.

EDIT: Ah ok! Thanks Svetlin. I think global damping will do. Although, I'm experimenting with distance tex mask's for the mapper thing currently. But it might be best to keep everything as simple as possible.

[Svetlin.Nikolov]

Yup, with the Tuners you can say "if the velocity is > X and the particle is inside Geometry Y, then damp the velocity"

As for the damping if the strength is zero, it should still work as per the docs: https://docs.chaosgroup.com/display/...+%7C+BodyForce Haven't checked the code, so if you find it does not work as expected, please ping us.

Cheers!

[MANUEL_MOUSIOL]

Cant wait to see the result!

[Ihno]

Me neither. ^^ I'll post it here.

[Ihno]

I'm trying to simulate the fake foam as highly viscous liquid which looks pretty good.
Now I'd want to use the milk simulation I did before (which fills the glass) as collider and emitter for the fake foam. It works as emitter, but the liquid gets cut by the milk as it moves. Is there a way to let it collide properly?.
The other option would be to animate a simplified collider for the surface. But I'm lazy... Also, I don't want to do that again when I have to change anything on the underlying milk sim.

[francomanko]

Just curious, how long is your sim taking to simulate?

[Ihno]

Which one? XD
I've got 3 for now.
The milk which is a liquid sim with low viscosity took 1-2 days.
The coffee is a smoke sim inside the milk, it takes 2 days to get a complete sim of the smoke but it took me lots of iterations to get there.
Like.. 30 or so, and I'm able to push 3 of them out every night(at least the first half, which is where everything happens).
And now the foam which will probably also take two days... I'm using two third gen ryzens and a second gen threadripper as simulation machines.
I'll probably sim some steam too. But one step after another.

[francomanko]

thats crazy