A couple of Workflow Questions

[Ivaylo Katev]

try with the voxelization mode, by default it is inscribed, to hide the water borders inside the geometry, but you can test with center or even circumscribed
in the nightlies this option is placed in the interaction panel
btw, the noisy horizon is fixed, tomorrow will be in the nightlies.

[ben_hamburg]

Ah, yes, I could have thought about that, there was that wine bottle example....
For now we just rendered an extra layer with just the boat and fied it in post, but i´ll keep it in mind for the next time.
And thanks for fixing the horizon! You guys are amazing!
We´re almost done with fluids now, two more simulations and we´re off for the holidays, hope you are having nice holidays as well!

[TSR_trix]

About foam pass workflow, has anyone idea how to get underwater foam pass which would have a proper ocean shade on top of it?
I mean, its useless to composite pale white particles into ocean pass without having a right kind of water fog shade on it.
I have tried to use matte options on the ocean, and visible to camera off, but I havent manage to get it to look same as in beauty pass.
Does people use refraction pass including underwater particles?

It would be so nice to have underwater particles on Atmospheric render element, but Im guessing its hard cause they are under another object?

[Ivaylo Katev]

the refraction pass perhaps? but it will catch the underwater geometry too....

[ben_hamburg]

I guess it depends on the kind of shots you are making, for us lowering the fog Multiplier in combination with the foam pass worked fairly well.

[TSR_trix]

My case is a simple boat cruising over the ocean. Its shame that if I render the ocean with foams UNDER surface, and then a separate pass with ABOVE against black BG, the composition is not same as in beauty pass.
It would be much faster to do such combo, beauty pass with under surface splahs/foams (13 minutes with MoBlur) and above splash pass (40 sec) or to do all in one beauty pass (38min). Playing with matte operations on Phoenix node wont bring any better results.

[ben_hamburg]

Just a little update on the noise at hte horizon issue:

about the noisy horizon - you have to increase both the skyline subdivisions and the image sampler. apparently this will lead to high render times, so i recommend to find some fake solution , why not blending with real image in post?

For the stereoscopic rendering of the project we have to more then double the resolution, so I had to spend some time optimizing the sampling anyway to get usable render times. So I went back to you first tip and upped the skylinee subdivisions from 2 to 8 and I think the render times onlyy increase about 2-3 Minutes per frame for the meshbuilding phase, so I think this will still be faster then rendering an extra pass with vraydisplacement plane..

[Ivaylo Katev]

btw the subdivision option was changed to affect really the horizon only. when the thread was started it affected the near scene too, that is just increases the render time with no additional quality.

[ben_hamburg]

Ah, thanks for the update! On a sidenote: Due to some Tutorial I read a while back, I´ve grown a custom to never set material glossiness to 1.0, but instead use something like 0.99, following the theory, that no material in real live is purely glossy.
But by setting glossiness on my ocean shader back to 1.0 the scene immediately got 50% less noisy...

[Ivaylo Katev]

glossy 0.99 and 1.0 are shaded in completely different way. any glossy below 1.0 produces multiple rays in different random directions, and every ray hits different point, this produces the noise.

[ben_hamburg]

Ok, now I need to come back to our mesh penetration problems.
We now have 4 new boats to do sims on, all of them at the same speed of around 40 knots. I´d like to get it right once, so I can reuse the settings on all of them.
I tried setting the voxels to circumscribed like you proposed, but that didn´t seem to help much, I can still clearly see the liquid mesh going through the boat in wireframe mode.
right now I´m simulating a 50m grid with SPF set to 6.
So any idea on how to improve collision detection? Set SPF higher or make grid cells even smaller (grid size is at 70x20x5 m, cell size at 0.055m)?
Or do I need to improve the collision dummy of the boat (I kept it sort of low poly on most parts)?
Right now there would still be enough time to increase simulation time for the finals, if we get better results that way, just not enough time to do more extensive testing...

[ben_hamburg]

By the way Ivaylo...you should really change your avatar, it looks so tired, that it always makes me feel bad for asking so many questions...

[Ivaylo Katev]

hahaha, actually the drawing is made during a weekly meeting, it's good to look tired during the meetings
about the geometry - why not use coarse copy of the boat just for the simulation? it can be build from scratch in few minutes.

[ben_hamburg]

Haha, I see...

Well I actually thought more polygons would be better for good collision detection, since Dummy itself is quite lowpoly.

[ben_hamburg]

The mesh at the front of the boat is quite thin and I´m seeing the most penetrations there. Do you think it would help if I increase the grid resolution?