Ship in Ocean

[waaazoo]

OK, that's a sim based on cm units (maya), and "from maya" (phoenix) units, so cm (am I wrong???)
as you can see, the wake behind bow looks correct, but at bow we have some blobs coming up....




https://vimeo.com/202349789

today, I'll keep the same scene, and will just change the Units, Units Scale in Phoenix and see what happens. Grmpfff

[Brainwave]

Hi Waaazoo and Flipbook,

Flipbook is correct, in 3ds max the units displayed in the viewport are a way of scaling your scene properly with other scene objects.
The system settings are the most important factor.

You could experiment with your work and grid units.
These units would do the same as the trick i do in 3ds max, work units would probably be scene units and the grid units could be display units.
But i am not sure if this is the case, it could be the other way around.
The only thing you need to take into account with this setup is that if you import files, you need to double check the scale of your imported objects.

The results i get are much better now, the liquid is properly scaled and i get nice v shaped liquid waves at the bow of ships i simulate.
The SPF settings are also important for better looking liquid simulations.
Try a SPF of 2 to 3 for speeds up to 20 knots and 4 or higher if you need to simulate fast ships at 30 knots or faster.

[Brainwave]

Hi Waaazoo,

What is your current cell size in the Phoenix simulator in Meters?
Your probably need to set this to 0,13 M at least, this would also correspond with the grid resolution of the Phoenix simulator.
But we would first need to figure out which setting is the correct setup for your scene scale.
Are Maya units so called generic units?
In 3ds Max there are generic units as well but i never use those.

[waaazoo]

Hi Brainwave and Flipbook,

I'm pretty used to work with CAD drawings everyday, so I'm used to work with realworld units. I'm always working with 1 Maya unit = 1 cm. So, if I'm modeling a cube of 1m, it will be 100 maya units.
That said, my boat is 120m long, travels at about 10knots, and when I tell Phoenix to use Maya units at a Units scale of 1, I'm expecting to have "real world" behavior, 1 Phoenix unit = 1cm (maybe I'm wrong here).
If I'm telling Phoenix to use Meters with Units scale of 1, 1 Phoenix unit should be 1 Meter.... and if I'm telling Phoenix to use Meters with a Units scale of 0.01, then again 1 Phoenix unit would be 1cm.... (Am I crazy?)

When you both say that you are already "cheating" by telling Max that 1 unit is 20 centimeters, and phoenix is happy with that, it means for me that Phoenix is not behaving in "real world" units. Am I wrong ????

Brainwave, to respond to your last question: in Sim14, cell size is 15. Maya units are centimeter, Phoenix Units scale is 1, so, my understanding is that one cell is 15cm (Again, I might be misunderstanding something)

[momo1585]

I have a question. I'm doing a scene with a long 9mt boat but I can not understand why the simulator does not work. The problem is the scale of the scene or something else? I put the picture of the boat and scale settings in maya.

[momo1585]

[QUOTE=momo1585;723755]I have a question. I'm doing a scene with a long 9mt boat but I can not understand why the simulator does not work. The problem is the scale of the scene or something else? I put the picture of the boat and scale settings in maya.

<a target='_blank' href='http://imageshack.com/f/pnTH224Np'><img src='http://imagizer.imageshack.us/v2/150x100q90/923/TH224N.png' border='0'></a>

[Brainwave]

Hi Waaazoo,

To measure the actual cell size you can zoom in on the edges of your Phoenix simulator until you see the scale of the cells of the simulator.
Then create a box with the same dimensions as stated in Phoenix units and see how Maya reacts when it places the new box into your scene.
Maya's box should fit into one cell, if that is the case your setup is correct.

Note: Phoenix cell sizes are measured in display units in 3ds Max so your settings could be different in Maya.
Is your scene scale of the Phoenix simulator set to 1?

[Brainwave]

Hi Momo1585,

Could you provide a bit more information on your simulation and units setup?
What is the speed of your boat?
I am unable to view your images, with more info we are able to help you better.

[waaazoo]

Hi Waaazoo,

To measure the actual cell size you can zoom in on the edges of your Phoenix simulator until you see the scale of the cells of the simulator.
Then create a box with the same dimensions as stated in Phoenix units and see how Maya reacts when it places the new box into your scene.
Maya's box should fit into one cell, if that is the case your setup is correct.

Note: Phoenix cell sizes are measured in display units in 3ds Max so your settings could be different in Maya.
Is your scene scale of the Phoenix simulator set to 1?

yes, setup is so far correct. Cell size is 10 and when I draw a 10units cube it fits.
As said, I'm doing tests with different Units/Scale Units setups without changing anything else in the scene. I will post when it's done.

[waaazoo]

Hi Momo1585,

Could you provide a bit more information on your simulation and units setup?
What is the speed of your boat?
I am unable to view your images, with more info we are able to help you better.

same remarks here

[Brainwave]

Hi Waaazoo,

Great, i am curious about your results.
I am also testing with a couple of scenes and try some other tweaks to the scale.

[momo1585]

Hi Brainwave
i use a metric setup in maya the ship is a replica of http://www.jeanneau.com/it-it/boats/...rry-fisher-855


i don't setup correctly simulation.

[waaazoo]

Momo, looks good so far... and your Phoenix setup?

[Brainwave]

Hi momo1585,

Could you show us your Phoenix settings?
Did you create this model in Maya or is it imported?
If Phoenix produces strange simulation behaviour with your model, check the normals of your mesh.
The normals should face outwards, this way Phoenix sees your model as an obstacle.

[waaazoo]

Ok, here we go for a first round of tests.
As said before, I didn't change anything to the scene apart of the Phoenix "Units" and "Units Scale" as pictured in the screenshots.

First, Setting units to meters and Units scale to 0.2


https://vimeo.com/202364861


Second, Units in Meters and Units scale to 0.01 (we could expect to get back to what I had before with centimeters and Units Scale to 1, and that's what happens)
Sadly, it doesn't look good as we have again these tiny blobs running on the water surface.


https://vimeo.com/202365504


Third, Units in Meters and Units scale set to 0.02 (to me, it's wrong in scaling, but suddenly it starts to look like something)
Still some blobs running, but much less noticeable.


https://vimeo.com/202364838

Svetlin, any comments on all this?

As you can see in the screenshots, with test1 cell grid is at 600m X 800m X 180m so totally exagerated
test2 is at 30m X 40m x 9m (as in reality, in my scene)
and test3 is at 60m X 80m X 18m (and looks quite ok)
So, my conclusion, so far, is that Phoenix needs to be cheated to think that its twice as big as in reality to have a correct result.