grid resolution for scale in scene water fall

[s_gru]

i've been playing around with an emitter of a box that's 8ft x 3" x 3" and having the water flow down onto a marble floor/steps. i have a cosmos person standing next to it. i am noticing that i really need to increase grid resolution for the water on the floor to look "in scale" with the person standing next to it. so for exmaple right now i'm down to cell size of 0.096".

i'm wondering if i could create a lower resolution falling water, then when it hits the surface of the marble steps, switch to a high resolution grid?

or is there generally any tips on something like this. i've attached image for what i'm doing. i think this is a grid res of 0.25" (inch)

[s_gru]

also, i am wondering a bit about how to smooth out the water as it's falling down?

[georgi.zhekov]

Hey,

Sounds like a job for cascading simulations. You can find more about how this works here - https://docs.chaos.com/display/PHX4M...naCascadeSetup

As for the smoothing of the water check the link here - https://docs.chaos.com/display/PHX4M...+and+Smoothing

Cheers!

[s_gru]

well what do you know! it was really awkward to begin with, but i think i got it. for some reason the top step was duplicating the shape of the vertical falls and duplicated the simulation instead of sprawling out along the floor. then i just recreated all of them one at a time.

any tips on how much overlap you need for the simulation boxes or the simulation start frame overlap?

yeah i'll look at that smoothing of water. also notice i changed the slot-water-fall to six 0.75" diameter circles. i found out that you need to have a grid size small enough to emit from that small of a diameter circle.

ultimately, i'd like to figure how to get a nice smooth column of water without it breaking up into pieces until it hits the floor.

i think this is a lot faster to simulate overall - it sure seemed like it. i was playing with the auto-expand grid and of course it renders really fast until the grid gets big! ha. so really glad to see this.

and to my earlier point, the scale seems off, it seems too big, for real-world. but i bet my individual grid sizes being smaller than 0.25" will solve that. i'll try 0.125" for each of them and re-simulate.

thanks!

EDIT: PS this is 8 steps per frame.

EDIT 2: oh, and if i think the water is flowing too fast, all i need to do is change the time scale then to slow it down? i think i'm getting the hang of things!

[Svetlin.Nikolov]

Your overlap seems quite enough - it's not too small, nor too big. Beware that after all, each simulation produces a separate mesh, so these meshes will intersect when rendering. You need to pick the intersection spots so that it doesn't show in the render that the meshes are separate and overlapping, which I think worked out quite well in the render you shared.

Note that if you use Mesh Smoothing and enable the Use Liquid Particles option, it would allow you to shrink or expand the mesh by changing the particle size. So if your mesh looks bloater right now, you can make it thinner.

Also, beware that Surface Tension, which water should have a little of, could break up the falling water into separate chunks, so try reducing it as much as possible - if you go too far, the water might start looking as sand, but depending on the scene, this might not be too bad.

And one more thing - you can cheat the scale by changing the Scene Scale option in the Grid rollout - try increasing this in order to make the water look slower and more cinematic

[s_gru]

oh ok, you can still use the scene scale. i wasn't sure which was best to use.

i think my surface tension is 0.0 right now. it doest seem intuitive, i would have thought a higher surface tension would pull things together more?

otherwise thanks, i'll play aroundw ith these suggestions. i did already calculate on a grid size of 0.125" and have yet to render it out, but i think it looks ok. interesting on the mesh smoothing and use liquid particles, that sounds great!

thanks on the overlap comments. got it.. can play with those as needed then. just want to make sure they are overlapped

[Svetlin.Nikolov]

i think my surface tension is 0.0 right now. it doest seem intuitive, i would have thought a higher surface tension would pull things together more?

Oh yes, it would pull some of the particles together at the expense of their neighbors, so by clumping the liquid more in some places, other places would remain empty.

[s_gru]

ok. i'm trying the mesh smoothing and also default settings for moblur.

hey, i just hit the play button to simulate... now, i have a question about this. i have the tall vertical selected and hit the play button on the menu bar. but it looks like it's simulating all of stepped simulations as well. before, i was clicking on each simulation box and hitting "start" within the settings - each box had it's own start/end frame number. is it ok to use the "universal" simulate button on the menu bar???

also, i set the moblur and mesh smooth in each of the simulations but is that necessary or do the cascaded simulation inherit setttings from the main one?

thanks.

[georgi.zhekov]

When starting the simulation from the toolbar without a selected simulator and you have more than one simulator present in the scene - there will be a prompt to select which simulator should start. If you have a simulator selected, the toolbar icon will start that one.
Feel free to use whatever is easier for you, either the toolbar icon or the button in the simulator itself, there shouldn't be any difference between the two.

When starting a simulation - you can't run more than one simultaneously. The preview will be updated for the rest of the simulators, but they are not really simulating.

As for the cascade - settings are not inherited, you will have to dial them manually. Sometimes you might want to have different settings for each simulator so inheriting the settings is not always desirable, although using the same settings will produce more consistent results.

[s_gru]

thanks georgi!