Is it possible to simulate rain with the fluid simulator?

I tried to do something with a bunch of Inflow cubes that get enabled and disabled, however this is very tedious. Is there a better way?

I realize that using a fluid simulation is probably overkill, I'm attempting this as a test. I should also note that I only want this for the simulation of the impact of the droplets on a hard surface, so I only need to simulate ~50 or so droplets.

  • 3
    $\begingroup$ I really wouldn't recommend this, even if you have tons of ram. Particles and dynamic paint are a much better alternative. $\endgroup$ – iKlsR Nov 17 '13 at 0:44
  • $\begingroup$ WOW. Why do you want fluid for rain ? Is it for testing purpose ? Instead you can use "fluid" type of particle's physics... $\endgroup$ – Polosson Nov 17 '13 at 0:45
  • $\begingroup$ The main reason is because I want to have it collide with a mesh and run down the sides etc. (The whole thing is a test) $\endgroup$ – gandalf3 Nov 17 '13 at 0:48
  • $\begingroup$ @gandalf3 Particles can collide, you could probably fake the rest with dynamic paint and animated droplets etc.. not sure if Blender supports wetmaps either? $\endgroup$ – iKlsR Nov 17 '13 at 0:52
  • $\begingroup$ @iKlsR Well, I know they can collide, but I mean collide with realistic splashing, splattering and spraying? I am trying this a test anyway, so I'm not really looking for the most efficient way to do it (though that would be good to know too..) $\endgroup$ – gandalf3 Nov 17 '13 at 2:30

You can try the Fluid physics type in a particle emitter :

  • Add a particle system to a plane and configure it the way you want (number, start, max age...)
  • In the Physics panel, select Fluid.
  • Select the object you want the particles to run down on
  • Add a Collision physics modifier to this object (make sure it has enough faces), with particle damping Factor set to 1
  • hit play and:

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Next, you just have to create a nice shader (this one is a blueish transparent shader, just for demonstration, very bad)

However, this type of simulation is not very realistic and some tweaks may be needed to suit your needs. It's just a track...

  • $\begingroup$ Thanks for your answer, though I take it there is no way to mesh these into a single solid object instead of a lot of spheres? $\endgroup$ – gandalf3 Nov 17 '13 at 2:28
  • $\begingroup$ This would be great, indeed... But I don't know how. Metaball instance for particles, maybe ? $\endgroup$ – Polosson Nov 17 '13 at 15:11
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    $\begingroup$ Protip: metaball instance for particles (if you can get it to work; I've done it in the past but it's tricky and unpredictable) is an excellent way to melt your CPU. Once you start getting into the hundreds it'll take a long time to orbit the scene, much less render. $\endgroup$ – wchargin Nov 17 '13 at 17:17

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