Ship in Ocean

[Ivaylo Katev]

for example if you have a boat and see it from the top, it's very easy to get different left and right wake parts when smooth is used.
in general. the smooth conservation is an alternative for the cases when the symmetric one leads to instability or artifacts. for example the liquid simulations with symmetric and FT are not stable.

[TSR_trix]

Ok, thanks Ivo, very good to know.
I have generally always left conservation to smooth, cause I havent got any proof of cases where symmetry (excluding nuke, which is a good example) or slow motion could be better.

[waaazoo]

I think I found the "secret" of your ship in the ocean simulation. I was always concentrating on the grid, waves, wakes and the foam. But actually what makes the difference in your settings is the splash !
It makes much more foam and everything looks better. I could find out thanks to resimulation which is really much quicker to test when you simulated already the liquid.
So, when you need foam, you should splash a lot ! Stupid me

[Ivaylo Katev]

yes, the setup uses "foam on hit" option of the splash, this means more splash=more foam.

[waaazoo]

Hi,

I'm back to this with FD 3.0 Beta. Was there ever a Maya tutorial scene made ? For now, I'm trying with my old scene.
I'm hoping to get a nice ship in ocean made in the next days.

[Svetlin.Nikolov]

Hey,

Negative - Maya samples will be underway during the Beta. You can give the Ocean preset a shot as a starting point as well.

Cheers!

[waaazoo]

ok, thank you. I'm trying to use the preset. no I have to get again a good idea about these units, I forgot what I learned some while ago.

[waaazoo]

Is there a little step by step somewhere ? I mean like:

- set units to cm in Maya preferences
- select your boat (100m yacht for example)
- click on "create ocean sim for the object"
- your units (grid, units scale, etc... should look like this)
.....

for now (I'm basically doing this), all looks off scale.... and I'm having trouble understanding the relation between units scale, and the rest.
I know it sounds stupid.... but when you start, you don't really know where to start

....

[Svetlin.Nikolov]

Hey,

When using the Quick Setups, the simulation scale would be automatically adjusted depending on the scale of the geometry you used the preset on. The Unit Scene in the Grid panel will be automatically adjusted so that no matter what your units are set to and no matter the scale of your object, it will behave in the simulation like it's as big as a ship for the Ocean preset, or as small as a candlewick when the Candle preset is applied.

If things look off after you use the presets, give us a shout - there might be something that needs adjustment on our side.

In general, even when not speaking about the presets, Phoenix's simulations would look correct when the object you simulate is in the real world scale. No matter if you are looking at the units in cm or meters - this is not accounted for - what matters is that if you are simulating a ship that is 100 meters or 10000 cm long, it should be this big in the scene as well, and the Phoenix units in the Grid panel should be set to reflect that. If, for some reason, you can't touch the size of the geometries in the scene, you can adjust the Unit Scale in the Grid panel so that Phoenix would behave like the simulation is actually bigger or smaller than what it really is.

Hope this helps, cheers

[waaazoo]

ok, thanks for the explanation. I tried out and will let you see the result.

even if, as I understood, it's not so relevant, I'll give you my setup.

Using Maya 2014 (I know it's old...)
Preferences set up to cm
Boat is 9800 maya units long as it should be 98m
It's travelling at about 18 knots.

I have my boat, select it, and use "setup an Ocean sim for the selected objects", and that's the result:

with sim not attached to boat
https://vimeo.com/194854129

with sim attached to boat
https://vimeo.com/194854073

[waaazoo]

and here another test where I scaled by 20 the group (boat + simulator). I had off course to scale the speed also. Looks much better already.

https://vimeo.com/194859016

I wonder how Phoenix is supposed to know if it's a small tiny boat or a huge one.

[Svetlin.Nikolov]

It should think it's a big one in the preset, but seems like something is wrong. Would it be possible to attach the scene so I can have a look at the particles that are produced at the borders as well?

Thanks!

[waaazoo]

Please let me double check with a completely new scene. I will upload if I don't get it to work, no problem.

[waaazoo]

ok, for now, here are two new scenes. One is with a simple polysphere with 50(cm) radius, there other is with a simple boat which is 100m long.
I will do more tests....

https://vimeo.com/194942800

https://vimeo.com/194942788

ocean_FD3_test2f.zip
ocean_FD3_test3a.zip

another test with preferences set to meters. I think the picture speaks by itself. Please let me know if I'm missing something here.....

[waaazoo]

I thought I should give it a try in Maya 2017 and I had some surprises.
The good news is that it seems much faster to compute in Maya 2017. The bad news is that there are some bugs. In both scenes, the mesh preview is not at same level as the initial fill. On the boat scene you can also see that the mesh is not following the simulator.
Same steps as in Maya 2014, all done with cm in preferences.

First the ball.

https://vimeo.com/194958584



then the boat.

https://vimeo.com/194958537

https://vimeo.com/194958502



UPDATE: if I reload the Maya 2017 scenes, the mesh preview is at correct level!