Small scale FlipSim surface problems

[smoke_solver2]

Hi!

I’ve been struggling with a water simulation for over a week now. I have a boat animation, the boat itself is 4 meters long. I export the whole simulation as an Alembic to Blender afterward (that’s just the workflow, can’t change it). To create the simulation, I’m using the Guided Ocean Layer from the shelf tools as a base. I resize the tank, crank up the particle separation to get around 20 million particles, and here’s what happens:

The water surface has a lot of noise, so when I mesh it, it looks like this:

I have to increase the particle radius scale to 2.0 just to make the surface look somewhat smooth, but that makes the water around the paddle look like jelly.

Of course, I can apply filtering and smoothing. I even tried using Delta Mush to smooth it out but then I lose detail in the collision areas, whether it’s the paddle or the net I later drop into the water. And even with these operations, the water surface still ends up with little dots on it, making it look like it’s lightly raining.

 

If I scale the whole simulation, including the collision geometry, by a factor of two (adjusting the particle separation so that the domain still fits around ~25 million particles), it slightly improves the situation, although not much (visualizer is cranked up here compared to the first one so it might not be obvious):

The surface no longer has that heavy grain. However, another issue is the lack of proper water interaction with the collision objects. There are no ripples spreading across the surface from the paddle. What I’m aiming for is the look of a boat gently moving across a calm lake surface:

If I scale everything up 5x, the water surface in the simulation becomes much smoother or more precisely, the velocity field is smoother. The dots disappear, and the mesh instantly looks better:

 

I also get visible waves spreading from the paddle on the water surface. But now everything looks like it’s in slow motion because, well, the boat is now 20 meters long.

 

This is still nowhere near good, you can see grain on the surface, but interaction with collisions are much more dynamic, fluid, than in the smaller, proper scale (also waves are too high here, just a side note).

So my question is: for a simulation on this kind of scale (around 4 meters), where I want subtle water movement on the surface but also nice ripples spreading out, I shouldn't be using flip sim? How can I correctly achieve that effect? I'm honestly exhausted. Watched dozens of tutorials, asked in many places, waited around 60 hours for all these sims and I still can't get it right. Even thought about buying LiquiGen of FlipFluids for Blender...

 

This is the look I'm aiming for (with throwing a net later on in the same scene, so I guess ripple solver isn't a solution here? [made in Veo3..]):

 

Edited Friday at 10:49 PM by smoke_solver2

[smoke_solver2]

Small update. I've made sim only around paddle. Model is scaled up 2x from the proper, original scale. I've multiplied velocity by 5x. There is 20mil points in this square sim. There are some ripples, although tiny and only around paddle. So I assume I would need a 1billion point simulation on my whole region to get proper dynamics? Something seems off.

Edited yesterday at 07:23 PM by smoke_solver2