Small hose falling into large container

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tedesco
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Joined: Tue Sep 22, 2009 2:09 pm

Small hose falling into large container

Post by tedesco » Sun May 15, 2016 2:01 pm

I'm trying to simulate one of those kids structures in water parks.
There is a big bucket with two hoses pouring water into it.
If I fill the bucket and make it spin it works great, but as the hose is so small I have to increase the scale size a lot so it works.
Now I'm making two separate simulation one with scale 1 that I make the big bucket simulation and another just for the hoses.
I'm using a simple emitter for the hoses and a fill object for the bucket.
I wanted to make just one simulation, but if I increase the scale the bucket simulation is insanely slow.
Any ideas?

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bitSeq
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Re: Small hose falling into large container

Post by bitSeq » Mon May 16, 2016 1:26 pm

Sounds like you need to adjust the resolution on your emitters and not the scale.

If you need it all as one simulation and the hose resolution needs to be high then the fill emitter needs to be the same resolution or the simulation will not work.

You can try two simulations like you mention with different resolutions and the liquids will not interact with eachother or one big simulation.

Dyverso may be a better solution for you as it is much faster than SPH.

tedesco
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Joined: Tue Sep 22, 2009 2:09 pm

Re: Small hose falling into large container

Post by tedesco » Mon May 16, 2016 1:52 pm

The problem is that for the hose to have a decent emitter size I have to increase scale 32x. if I leave a smaller scale emissions behave weirdly. Even having a resolution of 1000

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bitSeq
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Re: Small hose falling into large container

Post by bitSeq » Mon May 16, 2016 3:01 pm

Sounds like your world scale is far too small.

tedesco
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Re: Small hose falling into large container

Post by tedesco » Mon May 16, 2016 4:36 pm

Each grid box is supposed to be 1m.
My scale is correct.
The mais issue is if you start using your emitter with a scale like 0.01 it doesn't work very well, so I mess with the general scale so if I put scale X2 I also put the forces X2.
But again, that is not the issue. The main thing is that I have a large water simulation interacting with a small one.

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bitSeq
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Re: Small hose falling into large container

Post by bitSeq » Mon May 16, 2016 4:53 pm

Generally when working with small scale in RF I find you get much better results with the SPH standard emitters at a much larger scale, say x10, leave the forces scales at 1.

Yes your simulation will appear slower and large scale but this can be counteracted by using the FPS in the simulation settings.

Realflow is not a physically accurate system as the simulation engines are hugely optimised, it is common place to rely less on the engine and more on your eye as to what looks correct.

I would say that your bucket should be 4 or 8 grid squares in diameter, run some low resolution simulations and play with the fps till it looks how you want it.

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