Ship in Ocean

[waaazoo]

I'm simulating now with FLIP. After 20 frames, it looks like I have to review plenty of settings (much less foam and splash). It doesn't seem to behave as before.

[Svetlin.Nikolov]

Definitely - it's a whole new solver, so a lot of the settings don't translate exactly from the old one to FLIP.

You need the particle Age for all settings that sound like timeouts and lifespans - you gotta have it for the Outside Life.

If there's anything I can help with, please do ask

[waaazoo]

Hi,

Some progress
This time, FLIP is used. I changed some settings (attached - all other settings are as shown before).
Sadly, only 200 frames were generated.
Now, no foam is following the Hull underwater (which is good). I'm surprised that there is no foam generated by the propellers (which happened with the other solvers).
I'm trying to add a liquid source to the propellers. Is that the way to go ? I copied that from the ship tutorial.

If I wanted to avoid the streaks generated in the front, what should I do ?





https://vimeo.com/202009245

https://vimeo.com/202009033

https://vimeo.com/202011853

[Svetlin.Nikolov]

Hey,

So, it's important to know that there are several ways to generate foam - foam can be generated naturally by the liquid, which is controlled by the Foam Amount and Velocity Threshold parameters. It can also be born by Splash particles hitting the liquid surface - this is controlled by the params under the Foam on Hit sections. And, in case you need to generate foam in special places, you can use a source and create it from there.

You have disabled the natural foam birth by setting the Foam Amount to zero, so the only way your foam is born is by splashes hitting the liquid surface - this is why you get the streaks of splashes spawning foam at the front, and this is why the ship body and the propellers don't get to spawn any foam by their interaction with the liquid.

So you need to increase the Foam Amount and then experiment with the Threshold. You can also reduce a bit the amount of foam born by Foam on Hit. You need to find the ideal balance between the foam born in both ways

Hope this helps

[waaazoo]

Got it Svetlin! I'm trying to get a little foam directly from the liquid and then by splashes as before.
I wonder if it would be possible to generate foam just by splashes but add a turbulence field at the propellers to generate some extra foam...
I will probably post new videos tomorrow.

cheers

[Svetlin.Nikolov]

Good luck! And thanks very much for the detailed videos and settings - these are very helpful in determining what needs to be tweaked!

[waaazoo]

Good luck! And thanks very much for the detailed videos and settings - these are very helpful in determining what needs to be tweaked!

You are welcome, Svetlin. I don't see how you could help without seeing what is done here.

New sim from overnight:

Not so happy with the result. Sim13 was much better. I have to try again with smaller grid to speed up the simulation as over night it did less than 400 frames.
I would so much be able to get what we can see in the boat test you did at Chaos Group

here is a reference on what should happen with the propeller:
https://www.youtube.com/watch?v=DDsPag56GQE




bow view:
https://vimeo.com/202182781

stern view:
https://vimeo.com/202188487

underwater stern view:
https://vimeo.com/202194352

[waaazoo]

where do these "artifacts" come from ?
I'm trying to understand.... I thought they are generated by the splashes, but obviously not. I'm doing a test with splashes, and the same without splashes (just direct foam), and they are still there.




ok, here are the two sims. sim 15a is with foam and splashes (no initial foam birth), and sim 15b is without splashes but initial foam birth.

SIM 15A


https://vimeo.com/202236558

SIM 15B


https://vimeo.com/202241217

[waaazoo]

could someone translate the boat tutorial scene from Max to Maya ? I don't have the two apps here but it should be pretty simple to "send to Maya" the boat with it's animation. I would just need this without the phoenix stuff, to have a good comparision scene.
I'm still thinking that there is a scale/units problem. Running now a simulation without foam, just the sea. I would like to see how the wakes behave. I have the feeling that it will be nothing close to the boat tutorial.
It's getting slowly on my nerves

and.. btw... it's much faster to batch simulate, good news !

[flipbook]

I would but I think you need Maya installed to be able to do it Greyed out anyway.

[Brainwave]

Hi Waaazoo,

You could try to change your units setup in Maya.
I work in 3ds Max and i have set my display units to meters and my system scale units in 3ds max to 20 centimetres.
The Phoenix simulator was created manually, no quick preset.
The scene scale of the simulator is set to 1.

This way you probably get a better looking liquid simulation, your foam and splash would benefit from this as well.
I tested this myself a few days ago and i get better liquid simulations with these scale settings.

[waaazoo]

I would but I think you need Maya installed to be able to do it Greyed out anyway.

Yes, you need both apps installed but thanks !

[flipbook]

Brainwave does have a point First thing I do is very low res sims to get the scale right then tweak from there. I normally control using the scene scale of Phoenix as I like to keep things at 1cm units in max.

[waaazoo]

Hi Waaazoo,

You could try to change your units setup in Maya.
I work in 3ds Max and i have set my display units to meters and my system scale units in 3ds max to 20 centimetres.
The Phoenix simulator was created manually, no quick preset.
The scene scale of the simulator is set to 1.

This way you probably get a better looking liquid simulation, your foam and splash would benefit from this as well.
I tested this myself a few days ago and i get better liquid simulations with these scale settings.

What you say goes in the direction I'm thinking. There is a scale/unit problem or misunderstanding. For now, all the latest sims were created with Maya settings in cm and phoenix using maya units. It doesn't seem to be right. I'm testing now, just the look of the wakes, with some other unit settings.
I'm a little confused by the display units and system scale units you are speaking about. In Maya, we have the "work units" (usually set to cm for me).... and the grid units which I don't really use. Can you please elaborate?

[flipbook]

The display units in max mean nothing, it is just that, for display in the viewport. The system units are important in max. I would assume work units in maya relate to system and grid units to display