Foam and splash more natura

[luizfernando_fonsecapimentel]

Hey guys, how can I make this foam and splash more natural? They are a little coarse... I wish the particles weren't so hard.

[olika]

would love to see your sim stats,
like what time does is take for a framestep, splash foam amounts etc.

if you suffer from long sim times, i guess you could settle down a bit with the sim itself.
Looking just at the settings, 250 millions voxels seems quite a lot,
i do a lot of sims in the 60-100 million range.
Same with the frame steps, 3 is quite consuming, especially with such a grid.

Renderwise, you can try to lower the brightness of foam and splashes in the particle shader,
just a bit of grey instead of plain white and a bit lower diffuse multiplier is doing wonders here.
Seems a bit overexposed and therefore it blends all together in that white mud

It can help to do some rendertests with foam, splashes and mist separated to get a better understanding about what is going on.
hope that helps in a first step!

[zdravko_pavlov1]

Hello and thank you for posting. Indeed, olika is right. You have to tweak the settings inside the particle shader and not the ones in the simulation settings. You can also point the shader to the liquid simulator (if it is not done automatically as it should by default) and by doing so, the foam that is under the water will pick some of its coloring, making it look more natural.

Here is the documentation page that contains all of the particle shader info:
https://docs.chaos.com/display/PHX4MAX/Particle+Shader

Cheers

[luizfernando_fonsecapimentel]

would love to see your sim stats,
like what time does is take for a framestep, splash foam amounts etc.

if you suffer from long sim times, i guess you could settle down a bit with the sim itself.
Looking just at the settings, 250 millions voxels seems quite a lot,
i do a lot of sims in the 60-100 million range.
Same with the frame steps, 3 is quite consuming, especially with such a grid.

Renderwise, you can try to lower the brightness of foam and splashes in the particle shader,
just a bit of grey instead of plain white and a bit lower diffuse multiplier is doing wonders here.
Seems a bit overexposed and therefore it blends all together in that white mud

It can help to do some rendertests with foam, splashes and mist separated to get a better understanding about what is going on.
hope that helps in a first step!

Hello. Thank you very much for your answers... I have a few more questions:
1. What would be the ideal number of steps for this type of simulation?
2. How can I reduce water particle size? I thought it was too big... It's really thick. (image 1)
3. I did 2 types of simulations (images 2 and 3), which would be the best option?

4. I have attached the images you requested, the simulator statistics and particle settings. Thank you very much!

[luizfernando_fonsecapimentel]

would love to see your sim stats,
like what time does is take for a framestep, splash foam amounts etc.

if you suffer from long sim times, i guess you could settle down a bit with the sim itself.
Looking just at the settings, 250 millions voxels seems quite a lot,
i do a lot of sims in the 60-100 million range.
Same with the frame steps, 3 is quite consuming, especially with such a grid.

Renderwise, you can try to lower the brightness of foam and splashes in the particle shader,
just a bit of grey instead of plain white and a bit lower diffuse multiplier is doing wonders here.
Seems a bit overexposed and therefore it blends all together in that white mud

It can help to do some rendertests with foam, splashes and mist separated to get a better understanding about what is going on.
hope that helps in a first step!

It was not allowed to attach more than 5 images per response

[luizfernando_fonsecapimentel]

would love to see your sim stats,
like what time does is take for a framestep, splash foam amounts etc.

if you suffer from long sim times, i guess you could settle down a bit with the sim itself.
Looking just at the settings, 250 millions voxels seems quite a lot,
i do a lot of sims in the 60-100 million range.
Same with the frame steps, 3 is quite consuming, especially with such a grid.

Renderwise, you can try to lower the brightness of foam and splashes in the particle shader,
just a bit of grey instead of plain white and a bit lower diffuse multiplier is doing wonders here.
Seems a bit overexposed and therefore it blends all together in that white mud

It can help to do some rendertests with foam, splashes and mist separated to get a better understanding about what is going on.
hope that helps in a first step!

I looked at your work and thought it was amazing!!!

Your work on the Volvo Ocean Race was impeccable!!! In this simulation, how many steps did you take? And how many millions of voxels?

[olika]

yo! thx for the infos Luiz

1. is it on purpose you're going for point mode in splashes and not with bubbles?
(that's what i was actually wondering looking at your frame, like, are there splashes at all?)
If you don't want your splashes look similar to the foam you should try with bubbles instead of points.

If you do it for a reason (i.e. rendetimes) then we need to cheat the look a bit

With splashes as points i would:
- Make them a little bigger than the foam (i.e. 1.5 px or so)
- Make the foam more transparent than the splashes (alpha contribution in the point settings)
- Color the splashes plain red in the render for at least one time, to get a feel what is splash and what is fog. (this helps me over and over again to not get lost in the sauce, just sayin!)

Do you render the fog too? or did you just sim it?
Regarding the sim itself, i feel like i'm doing most of my stuff with like 10% of it


- Steps per frame is really needed for fast movements (an asteroid hitting the water surface or so where everything happens in that 2-3 frames of collision
But for a boat hull 1-2 steps should be totally sufficient. Pretty much only influences the front of the boat and the wake a bit

- Water particle size is the voxel size itself right? You want more detail in it, you need more grid voxels. But it seems yours are still very very small and leads to this 7minutes a frame.
With the right combi of settings overall you can get way down here


hope that helps!

[zdravko_pavlov1]

Hello,

When you say "water" particles, do you mean the liquid particles, or the splash and foam particles? Lets make that clear first so that we know what the problem is.

1. For more detail in the water mesh you can increase the simulation resolution. Or you can tweak the meshing settings in the rendering rollout of the simulation.
2. For the splash and foam particles (the ones that you are rendering via the particle shader). you are using "point" mode for both. Can you try switching the one that is rendering the splashes to <Splashes>? When you do that you can increase or decrease the size using the size multiplier inside of the shader..
3. When using the point mode the particles are shaded as flat circles with a size of 1 pixel by default. If you change the resolution of the render they may appear brighter or dimmer. You can adjust that by tweaking the Point Alpha parameter.
4. For the simulation steps per frame, you have to always use the lowest possible value. Higher SPF smooths the velocity and you are essentially losing detail in your sim. The exact steps needed really depends on your scene. How fast your boat is moving for example. Try starting with lower values and increase it until you have smooth result that you like, without too many "exploding" particles and chaotic behavior.
5. As for the grid dimensions it is always better to have it as small as possible in order to simulate faster and not produce enormous cache file, if that is not needed. How far it extends might depend on your camera angle. For wider shots, you may have to extend the grid just enough so that you don't cut of the waves.

Secondary particles such as mist, foam, and slashes, are allowed to live outside of the container and they won't be cut, but will gradually disappear, based on the Max Outside Age parameter

Cheers

[luizfernando_fonsecapimentel]

yo! thx for the infos Luiz

1. is it on purpose you're going for point mode in splashes and not with bubbles?
(that's what i was actually wondering looking at your frame, like, are there splashes at all?)
If you don't want your splashes look similar to the foam you should try with bubbles instead of points.

If you do it for a reason (i.e. rendetimes) then we need to cheat the look a bit

With splashes as points i would:
- Make them a little bigger than the foam (i.e. 1.5 px or so)
- Make the foam more transparent than the splashes (alpha contribution in the point settings)
- Color the splashes plain red in the render for at least one time, to get a feel what is splash and what is fog. (this helps me over and over again to not get lost in the sauce, just sayin!)

Do you render the fog too? or did you just sim it?
Regarding the sim itself, i feel like i'm doing most of my stuff with like 10% of it


- Steps per frame is really needed for fast movements (an asteroid hitting the water surface or so where everything happens in that 2-3 frames of collision
But for a boat hull 1-2 steps should be totally sufficient. Pretty much only influences the front of the boat and the wake a bit

- Water particle size is the voxel size itself right? You want more detail in it, you need more grid voxels. But it seems yours are still very very small and leads to this 7minutes a frame.
With the right combi of settings overall you can get way down here


hope that helps!

Thank you very much for the answer Olika.

Let's go...

1. I'm opting for point mode because of the tutorials I've seen on Chaos and elsewhere. Do you recommend putting it in bubbles?

1.1. What tips would you give me if I put it in bubbles?

2. I don't know if I rendered the fog or if I just simulated it... :s

3. Yes, can you do this with just 10% of what I'm doing? To reduce the size of the particles (voxels) I had to reduce the size of the simulation box. Is 7 minutes per frame too much?

4. In your Volvo Ocean Race project, did you use bubbles or points?

[luizfernando_fonsecapimentel]

Hello,

When you say "water" particles, do you mean the liquid particles, or the splash and foam particles? Lets make that clear first so that we know what the problem is.

1. For more detail in the water mesh you can increase the simulation resolution. Or you can tweak the meshing settings in the rendering rollout of the simulation.
2. For the splash and foam particles (the ones that you are rendering via the particle shader). you are using "point" mode for both. Can you try switching the one that is rendering the splashes to <Splashes>? When you do that you can increase or decrease the size using the size multiplier inside of the shader..
3. When using the point mode the particles are shaded as flat circles with a size of 1 pixel by default. If you change the resolution of the render they may appear brighter or dimmer. You can adjust that by tweaking the Point Alpha parameter.
4. For the simulation steps per frame, you have to always use the lowest possible value. Higher SPF smooths the velocity and you are essentially losing detail in your sim. The exact steps needed really depends on your scene. How fast your boat is moving for example. Try starting with lower values and increase it until you have smooth result that you like, without too many "exploding" particles and chaotic behavior.
5. As for the grid dimensions it is always better to have it as small as possible in order to simulate faster and not produce enormous cache file, if that is not needed. How far it extends might depend on your camera angle. For wider shots, you may have to extend the grid just enough so that you don't cut of the waves.

Secondary particles such as mist, foam, and slashes, are allowed to live outside of the container and they won't be cut, but will gradually disappear, based on the Max Outside Age parameter

Cheers

Thank you very much for the answer Zdravko.

Let's go...

What is the difference between splash mode and point mode?

His tips were excellent for the progress of my project. Thank you very much!!

[zdravko_pavlov1]

Well, Bubbles and Splashes modes are rendering as an actual spherical objects that will reflect and refract light. When in Bubbles mode, the particles are going to render even if they are under the water. Splashes will only render when they leave the water so it is more suitable for the small splashing droplets.
Point mode don't have reflections and refractions, but will also render when they are underwater. So for far away wider shots you can use it to render your foam particles as well and they will render faster and still look convincing. For closeup shots, the foam should be set as bubbles because that's what the foam is. A tiny bubbles of air. So in your case, I would set the splahes in splash mode, and the foam in point mode.

And here's the documentation page again. There are pictures there that you can look at and you can see and read all about the different modes and there is also a lot of other useful info regarding the particle shader.
https://docs.chaos.com/display/PHX4MAX/Particle+Shader

Cheers.

[luizfernando_fonsecapimentel]

Well, Bubbles and Splashes modes are rendering as an actual spherical objects that will reflect and refract light. When in Bubbles mode, the particles are going to render even if they are under the water. Splashes will only render when they leave the water so it is more suitable for the small splashing droplets.
Point mode don't have reflections and refractions, but will also render when they are underwater. So for far away wider shots you can use it to render your foam particles as well and they will render faster and still look convincing. For closeup shots, the foam should be set as bubbles because that's what the foam is. A tiny bubbles of air. So in your case, I would set the splahes in splash mode, and the foam in point mode.

And here's the documentation page again. There are pictures there that you can look at and you can see and read all about the different modes and there is also a lot of other useful info regarding the particle shader.
https://docs.chaos.com/display/PHX4MAX/Particle+Shader

Cheers.

Thank you very much for your enlightening answers!! I'll do the tests after finishing a render and come back with more news.