Boat simulation; issues with active body

[Svetlin.Nikolov]

Hey, there was a problem that entered the nightlies for a couple of days - please try today's builds instead and sorry for the inconvenience

[waaazoo]

Hi Svetlin & Georgi,
I have opened a Ticket (44572) and sent some playblasts, explanations and a scene. I really need your input

cheers

[georgi.zhekov]

Thanks for the files, we got them. Will get back to you when we have more info.

[JuhaHo]

Here's my latest simulation results. I still don't see decent side wake. I marked the level, where the wake is on the photos I've seen this hull running 50 knots.

It took more than 5 days to run this simulation. I wonder if I increase the simulation steps and restored let's say frames between 700 - 750? Does this make any visible step or gap to simulation cache files or rendering in general? Starting from beginning would mean more than one week simulation and there's no guarantee it get's any better.

Are there any other suggestions to improve the side wake? Or are there any ideas to determine the correct amount of simulation steps in speeds over 50 knots? Now I'm nowhere near, when compared to real life photos.

[Paul Oblomov]

Try to redo your animation or even bake it to I dunno... alembic maybe, so there's no animation keys at all. I remember there were weird stuff happening, when I parented one things to another. And maybe for testing purposes you don't need 48million foam particles
Also - may it be that your water just converts to splashes and foam and wake it kinda... dissolves ? What if you turn splash-foam system off completely?

[waaazoo]

Here's my latest simulation results. I still don't see decent side wake. I marked the level, where the wake is on the photos I've seen this hull running 50 knots.

It took more than 5 days to run this simulation. I wonder if I increase the simulation steps and restored let's say frames between 700 - 750? Does this make any visible step or gap to simulation cache files or rendering in general? Starting from beginning would mean more than one week simulation and there's no guarantee it get's any better.

Are there any other suggestions to improve the side wake? Or are there any ideas to determine the correct amount of simulation steps in speeds over 50 knots? Now I'm nowhere near, when compared to real life photos.

Yeah, it's weird that you need so much time to simulate. How much frames ? What kind of computer are you using to simulate ?
As Paul said, you could simulate only with liquid and splashes, but without foam, mist, wetting. That would run faster already.

[JuhaHo]

Yeah, it's weird that you need so much time to simulate. How much frames ? What kind of computer are you using to simulate ?
As Paul said, you could simulate only with liquid and splashes, but without foam, mist, wetting. That would run faster already.

I have installed Phoenix 5 on my laptop HP-Zbook as attached. I use it for this, because I have another Phoenix (version 4) project running at my main workstation. I have plans to study more Phoenix 5 later this summer when out of town on summer leave. Then I try to study active bodies as well.

[JuhaHo]

Here's a picture of the hull running 49 knots. This is what I'm trying to achieve.

[Paul Oblomov]

Share your hull dummy geo - will try
I don't see any problems here.

[JuhaHo]

Share your hull dummy geo - will try
I don't see any problems here.

Thanks,

I think, I'll never get a permission to share any geometry.

As on picture, there can be observed that the curved bow of is above the surface level. As soon as I raise the bow during the simulation, I lose the side wake. I wonder if I just try modeling an underwater bulge to the point where the hull touches the water. Maybe it would help to throw water sideways.

[waaazoo]

Thanks,

I think, I'll never get a permission to share any geometry.

As on picture, there can be observed that the curved bow of is above the surface level. As soon as I raise the bow during the simulation, I lose the side wake. I wonder if I just try modeling an underwater bulge to the point where the hull touches the water. Maybe it would help to throw water sideways.

I was pretty sure you can't share the hull mesh. I have maybe something similar, and if I can find the time I try to make a setup. I don't think adding an extra mesh underneath is the solution.
As for your simulation speed, I'm afraid your laptop is not the best solution so it's normal that your simulation takes a long time. I would definitely do all the testing without foam, mist and wetting, and try to reduce the grid as much as possible.

[JuhaHo]

I was pretty sure you can't share the hull mesh. I have maybe something similar, and if I can find the time I try to make a setup. I don't think adding an extra mesh underneath is the solution.
As for your simulation speed, I'm afraid your laptop is not the best solution so it's normal that your simulation takes a long time. I would definitely do all the testing without foam, mist and wetting, and try to reduce the grid as much as possible.

Working with laptop is of course a temporary solution. I have separate license for Phoenix R4 in my main workstation and it's engaged to another project. Once I have the project finished, I'll do the transfer to R5 there. Actually I made the boat renderings with R4 workstation by using the simulation *.AUR files, that had been generated by R5 in my laptop. No problem with the rendering. I have plans to catch up with the new features of Phoenix 5 by using the laptop during the summer leave.

[JuhaHo]

I created a simulation with extended keel and another with no keel at all. Neither of these worked. I really wonder why it is so difficult to create a simulation of boat that displaces water properly during simulation. Is it even possible to simulate a moving boat by using Chaos Phoenix 5?

I have shared in this thread a real life photograph and my simulation results. What would be the explanation for the differences? Could someone working for Chaos please comment and examine this. I'm running out of ideas.

[georgi.zhekov]

Hey,

Is it possible to send us any version of your scene so that we can try it here? From what I can see, there could be a few factors that could impact the side wake - the shape of your hull, the animation and the grid resolution.

In your case the sim gets really slow as you have way too many foam and splash particles, for the tests as the other people in the thread suggested - try to disable the foam, splash and mist and run a very narrow sim grid around the boat, this should speed up the sim considerably.

If the animation and the shape of the hull look good, then probably you need a bit more grid resolution. How large is your grid compared to the boat? Your grid resolution looks fine, but if the grid is too large it may not be enough.

[JuhaHo]

Thanks Georgi,

Here's a screenshot of the setup.