back to boat wake foam sim

[waaazoo]

Hello all,

I'm finally back to testing boat wakes & foam.
I'm starting to get some nice examples that I will post here, but I have also some questions about unwanted things.

First thing posted:
- I have clear water. The simulation was done using "clear inside" option for the Hull object (closed object)
- There are some unwanted water surface "artifacts" that are probably due to the liquid mesh penetrating or not the boat hull (seen on the bow).
- I tried to use rendercutter by using the hull mesh. On the bow, it seems to remove a bit the problem, but I get a straight line in the sea surface.
- On the example scene posted on the documentation I noticed that you don't use "clear inside". Is this example scene not outdated ?

any hints ?

[georgi.zhekov]

Hey,

The renders look quite good. Great job!

I can't seem to reproduce the issue with the line on the ocean surface. Can you try rendering using the latest nightly build? Also which version of V-Ray are you using?
If the issue is still reproducible, send over the scene and we'll take a look.

As for the "Clear inside" in the example scene, indeed it is not enabled but it shouldn't be causing any issues in this particular case. Why do you feel the scene is outdated?

Thank you,

[waaazoo]

Thank you Georgi for the nice comments. I should be able to post some animated tests soon. I'm quite satisfied with the results now, espexially since I added motion blur to the foam and splaches.

Sorry, I forgot to mention my software setup. Windows 10, Maya 2018.6 and Vray Maya 2018 Update1, and Phoenix FD 3.14.00
I could try the latest Phoenix nightly build, but I guess I will have to ask for access first (which I will do now).

I'm trying right now a sim without "clear inside".
As for the test scene, it was more of a question to ask if it might be already outdated as pretty all scenes seem to have been made under Maya 2015

thanks

[georgi.zhekov]

Ah, the scenes are saved for Maya 2015 as this is the oldest version we support, they should all be working correctly.
If you have some issues with them or the result you're getting is quite off from the one in the video, just let us know and we'll fix it.

Thank you,

[waaazoo]

Hi,

Here is an animation. Left side is a sim with "clear inside" for the hull and right side is exact same sim (new sim) but without "clear inside". It's pretty much the same result.

https://vimeo.com/345410957

What would you suggest to remove/enhance the splashes at bow ? For renderings I used "splashes", but tried also bubbles, cellular and points and nothing looks good. Do I need to have much smaller cells to get a nice result?
I could not test yet the cutter feature as I don't have access to the nightlies for now.

[georgi.zhekov]

Hey,

Looking good!

The birth of splashes can be controlled by the Birth Threshold in the Splashes rollout. You can try and increase that, but this will affect the rest of your simulation as well.
Another thing you can do is to use a render cutter object in the particle shader. This way you can create a dummy object that can cut away the splashes at the front.

The foam looks pretty decent to me. What is the issue you're having with it?
Increasing the grid resolution will add more detail and through the Particle shader you can control the render size of the bubbles.

As for the line you're getting with the cutter - can you send over the scene so we can take a look at what exactly the issue is?

Thank you,

[waaazoo]

Hey,

Looking good!

The birth of splashes can be controlled by the Birth Threshold in the Splashes rollout. You can try and increase that, but this will affect the rest of your simulation as well.
Another thing you can do is to use a render cutter object in the particle shader. This way you can create a dummy object that can cut away the splashes at the front.

The foam looks pretty decent to me. What is the issue you're having with it?
Increasing the grid resolution will add more detail and through the Particle shader you can control the render size of the bubbles.

As for the line you're getting with the cutter - can you send over the scene so we can take a look at what exactly the issue is?

Thank you,

I thought about a cutter object to remove only the splashes at the front. Not sure if the result would look nice.

I have no issue with the foam. I'm only trying to enhance the overall look.
I will send you the scene to check out the cutter line issue.

Right now I was trying to get some depth (fog) into the water, but the fog parameters are really tricky. I have to be stay with very very small numbers. I tried also the fog bias, but quickly (while raising the number to a nice result) I get a diagonal line under the water surface (I think this was discussed somewhere, but I couldn't find back).
I have only a dome light, a vray plane, the water sim and the Hull you can see in the render.

[georgi.zhekov]

For the diagonal line - try and increase the Off-screen margin. The ocean is generated only in the camera view, which can lead to problems when using camera motion blur, using reflections, using refractions with Underwater Goggles enabled, or when the ocean casts shadows on objects underwater. This option allows you to extend the ocean further from the borders of the camera view in order to solve such issues. The value is a percentage of the image size.

Try increasing it gradually as it will slow-down the render.

[waaazoo]

For the diagonal line - try and increase the Off-screen margin. The ocean is generated only in the camera view, which can lead to problems when using camera motion blur, using reflections, using refractions with Underwater Goggles enabled, or when the ocean casts shadows on objects underwater. This option allows you to extend the ocean further from the borders of the camera view in order to solve such issues. The value is a percentage of the image size.

Try increasing it gradually as it will slow-down the render.

Thank's so much ! now I remember that I had the same issue already. That was it !

[waaazoo]

As for the line you're getting with the cutter - can you send over the scene so we can take a look at what exactly the issue is?

Thank you,

I just got the nighlies access and tested with the 2018 29295 nightly. I still have the rendercutter line issue.

[georgi.zhekov]

Okey, send over the scene to the support guys and we'll take a look.

Thank you,

[waaazoo]

Scene was already sent via wetransfer to support. thanks. Let's see if I did something wrong in the scene.

[georgi.zhekov]

Hey,

Thanks for the scene. The line happens because the render cutter is still not implemented for the Ocean render mode. Unfortunately this is still in the to do list.
As for the liquid that is penetrating your boat - this happens because your geometry has open edges. If you fix that and run the sim again it should render correctly.

Cheers,

[waaazoo]

Hey,

Thanks for the scene. The line happens because the render cutter is still not implemented for the Ocean render mode. Unfortunately this is still in the to do list.
As for the liquid that is penetrating your boat - this happens because your geometry has open edges. If you fix that and run the sim again it should render correctly.

Cheers,

Thanks for the response. Good to know that cutter is not yet implemented for Ocean Render.

I'm surprised that I have open edges in the hull, but I will double check that. I'm building up a new hull anyway. Thank you !

[waaazoo]

Hi,

New SIM, new Boat Hull (closed mesh).
I have the feeling that the liquid is still penetrating the mesh. I'm trying smaller cells. I'm using "clear inside" and the latest Nightly (phoenixFD_adv_39001_maya2018_vray4_x64_29295)