Physics Dynamic Water Physics - Realistic. Fast. Universal.

YAY! FINALLY WAVES THE ONE THING I BOUGHT THIS FOR!

 

I'd like to see a demo of that.

 

Hi, what ocean / wave system do you recommend for this plugin that can support both mobile, console, and PC-based VR platforms?

 

There is now a demo for Crest and Lux Water here: http://dynamicwaterphysics.com/doku.php/Demos

 

If you are using Dynamic Water Physics 2 I would recommend Crest for sure. It is open source and getting more and more polished with each update - and they come almost on daily basis.

 

Dynamic Water Physics now has a discord: https://discord.gg/59CQGEJ

 

I am trying to modeling a ship but when I run the program the ship tilts on the left side.
I have done an other ship before and I didn't have any problem.
Can you help me with this?
Thank you

 

This one is easy to fix. Your center of mass is too high and therefore it tips over.
Just attach center of mass script that is included and lower the value on the Y axis.
If you already did that and it still tips over, make sure that the rotation of your model is correct (X-right, Y-up, Z-forward).

 

Thank you for the tips.
I am trying but in order to stay straight I have to lower the CoM with a quite a high value such as 9 and the draft of the ship is 6.
The axis are correct now (they weren't before).
I solved the problem using the hull of the first ship scaling it. The only remained issue is that the ship is rolling too much when I have rough sea. Can you explain what are the following parameters:
-Skin Friction Drag
-Dynamic Force Power
-Velocity Dot Power
thank you

 

I read what the parameters are on the code.
But I am still not able to have a good behavior in rough sea with the second ship: it jumps and turn a lot in all axis.

 

I am using DWP2 with Crest.
I am trying to modelling some big ships ,such as a Container Carrier with 325m of length. No matter what parameters I change, it seems to me that it is always rolling too much

 

Hello,
please try inreasing the angular drag on the Rigidbody a bit.
Normally large ships have some kind of roll stabilization but this has not been implemented in DWP2.
Check this video:

Or this Wiki article: https://en.wikipedia.org/wiki/Stabilizer_(ship)
Increasing angular drag will help to some extent but a small script that applies counter torque to the ship would be better. I.e. when the ship is tilted left add torque in clockwise direction and vice versa.
I have added this as a TODO.

 

Hey! i'm looking at creating a river simulation, objects flowing down stream.. specifically a raft
the asset R.A.M. seems to cover the shader part of this, does your asset have support for R.A.M.?
and if so, how well does it handle drops/slopes in the river

Kind regards!

 

I have contected R.A.M. publisher about two weeks ago and nothing. But since it is quite requested I will see what I can do. DWP2 supports both waves and water flow. I am preparing to do a larger update in the future.

 

try on discord

 

I am modeling a container carrier.
I am simulating a propeller that has always the same force and the ship is always reaching the same maximum speed, such as 17 knots.
If my ship collides with something it happens that ,using the same force, the ship reaches a much bigger speed, such as 20 knots.

I am applying the forces to the rigid body of Ship_local_pivot, the waterobject script is in "hull" gameobject and the collider is in "CollisionDetect" gameobject


Can you understand why this is happening?

 

Could it be that the collision pushes the ship slightly out of the water? This would reduce the drag on the hull and allow the ship to go faster.

 

After further tests I understood that this is happening always in a certain zone of a terrain. So it is not due to a collision.
Is there a way to know the value of the drag in each point?

 

That is interesting. What water are you using? A flat plane, Crest or something else?

 

We are using Crest

 

In that case - Crest uses LODs. I.e. the waves get finer and finer the closer you are to the origin. Could it be that if you are not using floating origin that the ship speeds up over LOD0 where the waves should be the highest resolution.

 

I'm just wondering if I can delete the Demo Content folder after import DWP2, it is around 200mb; also is there a tutorial for integrating with Crest

 

Hello. v2.2 will be getting rid of Demo Content folder and everything will be in a single directory so while you could in 2.1, the answer is no for 2.2. Besides, except for using space on your drive these files will not increase the size of your build.
As for Crest tutorial: http://dynamicwaterphysics.com/doku.php/WaterAssets
v2.2 will have some major improvements for Crest integration and make integrating 3rd party assets much easier tho. Check the posts above for the changes. The update is expected in a few days.

 

I am currently rewriting most of the docs for DWP2 2.2 as these have been updated so many times that I feel they lost some of the usefulness and do not cover all the bases.
Also, in 2.2 a new type of WaterDataProvider will be introduced: RaycastWaterDataProvider. RaycastWaterDataProvider can be used with any object that has a Collider attached to it. This should be useful for R.A.M. style assets or scenes that have rivers/streams/waterfalls implemented as a mesh with a scrolling texture.

 

I have a gameobject that represent the ship, it has a rigidbody with the mass of the ship.
This gameobject has several children:
-one gameobject that represent the "hull" of the ship and that contains WaterObjects script;
-some of the other children have colliders that I use for several purposes.
If one of these colliders is not symmetric respect the center of the ship and the "hull" collider the ship is going to stay bent on a side .
Can you explain what is happening here?
Thank you

 

If I understood correctly the colliders for the object are not fully symmetric and therefore the ship tilts to the side?
This happens because unity calculates center of mass as a center of all colliders, as if they all have uniform mass.
To fix this add CenterOfMass script to your ship (to the object containing the Rigidbody) and adjust the X value in play mode until the ship is level. Then exit the play mode and use that value for center of mass.

 

Hello!
Could you please upload video tutorials for RAM and Crest.
I followed the pdf manual and the boats and objects were not float.
I am stuck.
The demo scene of DWP2 works very well.

 

Hello,
the highest supported version of Crest in DWP1 is Crest 6. Later versions have different API.
RAM is not supported and never was in DWP1.
DWP1 and 2 are very different assets with not much in common (ship controller is similar but the WaterObject code is completely new).

 

I am using DWP2

 

Ah, OK then. Please also check: http://dynamicwaterphysics.com/doku.php/WaterAssets
just in case the offline docs are outdated (should not be).

Which one are you using, Crest or RAM? I am asking because they have quite different setups.
Also, could you say which steps have you made? Does it float as if using flat water (i.e. does not register waves) or falls just straight through?
And finally, do you get any warnings or errors?

 

1.

I tried both Crest and RAM.
The above is screenshot from RAM.
The followings are what I did.
1. I opened the demo scene of DWP2.
2. I disabled Water from Environment.
3. I added RAM Lake Polygon. Tag Water and Layer to Water (layer 4)
4. I changed RAMwaterprovider.cs.txt to RAMwaterprovider.cs.
5. I created Empty Object and assigned RAMwaterprovider.cs.

Play and all the objects were not float.

 

Could you PM me your project and I will take a look at it. Just remove the Library folder to reduce size. This will probably be the fastest way for me to debug it.

 

hi,

i'm using Unity 2019.4.11f1 and DWP 2.2.3.
I attached AUDIO SOURCE to the "Ship" but i'm getting error below:
No AudioSource assigned to Running Source field of object Capsule

i'm using the DuckIdle as the audio clip.
what can be the problem and how to fix it?

thanks.

 

@NWHCoding I have purchased DWP2, and it is really good! In our use case, we need a global ocean current vector and force. Can you implement this, so that this global vector force works realistic on the faces under water? Would really appreciate it. We did our own implementation, but it isn't work 100%. Also it would be more performance optimal to do this in the same pass when you add your forces to the faces.

Have a great weekend!

 

You most likely have to assign your AudioSource (not AudioClip) to the Running Source field of ship controller.
DWP2 does not create AudioSources by itself so you have to manually add this component and drag it to the corresponding field under Engine tab.

 

Hello,
luckily there is something like this already implemented.
Please check WaterDataProvider for Crest and you will notice that there is code for querying water velocities.
In short - if you are working with your own WaterDataProvider you just need to implement the function for getting velocities and set the values there. If you just need one velocity for the whole scene you can use the provided fill array function (you will be able to see this in some WaterDataProviders - fastest way to fill an array) and set the global velocity in one line for all objects in the scene.

 

Thank you very much for your quick reply. Keep up the great work! Check out our work at https://www.morildinteraktiv.no

 

@NWHCoding I have a question I hope you can help me with; When I have a water object, and add a constant force in z-direction. It then reaches a certain velocity. If I increase the force10 times, the velocity also increases 10 times. Is this correct? From my understanding this resistance should not be linear - but I am not sure.

 

There are a few factors:
- As the boat speed increases it moves from displacing water to gliding over it. Especially if the boat is very light.
- Default skin drag under WaterObjectManager is quite low.
- There is no air drag. Use Rigidbody Drag field to approximate this. Somewhere in the area of 0.01-0.05, depending on the shape.

So if you increase the force/speed enough at one point it will start pretty much flying over the water with only a small part of the hull touching. And lastly, it is an approximation - not a hardcore simulation - so a bit of tweaking of the settings will always be needed to get the feel you want.

 

Hi,

We've currently have DWP 1 integrated on many objects. I would like to know will it take long to migrate DWP 2,
since performance is very critical for us. It would be great to have some rough estimation for 1 vessel migration.

Thanks in advance.

 

Hello,
the assets are pretty much completely different. That said it depends on how many objects you have to (re)set-up. There is a wizard included that should speed things up or you could select all the objects you need to convert and batch modify them.
The performance gains should be huge (500%+) due to multiple major changes such as usage of ECS-like approach and multi-threading. Also, number of water queries has been reduced three times meaning that if you use wavy water it will run even faster. The only downside is that you need to run WaterObjectManager.Synchronize() after adding an object (not removing) to re-allocate native arrays which can be expensive.

 

Hello,

Considering getting DWP2 and have a question i cant seem to find an answer to, really sorry if i missed it somewhere.

Does it support runtime generation of boats ? meaning we dont know in advance the size or shape of the boat, so after assembling several objects into a boat we have the required API to specify at runtime floating points or whatever is needed to make it work.

 

Yes it does but there might be some issues if it is high poly. WaterObject script can use the original mesh from the MeshFilter to simulate the object or a simplified mesh. The algorithm for mesh simplification/decimation is not intended for runtime use so it would be best if the boat mesh did not have more than ~100 triangles so that the simplification is not needed.
DWP2 does not use floating points but the mesh triangles so you would need to provide a mesh that represents the hull shape.

 

sounds good, shouldnt be a problem to come up with a low poly version.

thanks a lot for the information going to try it out!

 

Hi, great asset but I'm having some issues with it. I'm not being able to use my own objects, they dissapear from the scene, I guess they just fall through the water. Tried with the included pins, rods etc and it works ok, but as soon as they touch the water they move for about 2 seconds and they stop, while in your demo they keep moving for a while. I use stylized water 2, latest version without waves. Tried enabling waves in SW2 but they don't seem to have any effect on the objects ( on the pins, rods etc)

 

Hello,
make sure to call

WaterObjectManager.Instance.Synchronize()

after adding new WaterObjects to the scene. It is suggested to add all the objects that you need and then call the function since it is quite performance intensive due to the need to resize native arrays.
If the objects stop bobbing or moving around too soon make sure to check the WaterObjectManager settings, especially the skin drag (lower = less friction) and dynamic force coefficient (lower = less impact force).

 

Thanks for your quick response, Is there any way to get some side movement in a flat water plane so they don't look so static over the water ? thank!

 

You could add some random forces to the object through Rigidbody.AddForce() or AddForceAtPosition(). Or maybe even better something such as a sine function to make them look as they are bobbing around. Or the combination of the two.
Something like:

Code (CSharp):

1. rb.AddForce(Mathf.Sin(Time.realtimeSinceStartup) * rb.mass * 0.1f * Vector3.up);

Just writing that off the top of my head but something similar.

 

Hi, I would like to buy it immediately. However I need this water shader to work with it:

The shader is so simple, can I ask you to insert it, working with a boat, in this awesome asset? I will buy the same day. Many thanks.

 

From what I can see from the video there is a function that returns the water height at position meaning that creating a WaterDataProvider for it would just require copying one of the existing WaterDataProviders (e.g. the Lux one) and replacing the water height function call with the one for the asset above.