Um, is there a way to confine particles to a closed space? Specifically I need to model plumbing for my glass fountain, and I want the emitter at the base of the thing so you can watch the water spray upwards, then out as it reaches the top. Any thoughts? I figure I could add one emitter at the bottom that emits particles straight up and have them die at the end of the pipe, then add another emitter at the top of the pipe that would let them spray out, but the easiest solution seems to be to “confine” the particles until they reach the top. Am I brain dead, or is this possible?
The ‘And’ value determines the spread of the particle column.
The ‘Norm’ value controlls the height.
You can get the top of the stack to ‘rain down’ on itself by setting the ‘Force Z’ value to a ‘-’ factor.
Other than this it’s difficult to comment because there are too many variables. eg: whether you are emitting from a vertice or a face or multiples of both. And the ratios between the particle life, endlife and keys. Crazy stuff!
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Hmmmm. That means that I still have to use two emitters. I should have said “Spread out” when they get to the top of the pipe. Well, thanks though, now I know what some of those buttons do! 
Hmmm, i think we should put a rule on the forumz, no speaking like an 1860’s prospector…
Matt
Blend on, and blend well!!!
The best way to control the particals the way that you want is with a lattice.
Just parent the lattice to the emitter, then click on RecalcAll. Placing the lattice in a kind of pipe will guide the particals. Every time that you edit the lattice you will need to click on the RecalAll button.
Good luck
You don’t need a lattice to do that, nor two emitters.
Place one emitter where the fountain will start.
The emitter should be a UV sphere, delete all but the north pole.
Eventaully squash it to have an emitter which is NOT planar but convex.
Give particles a strong Nor initial speed and low randomess, and a downward Z force.
Voilà
Stefano
Wow, I didn’t know I could control particles with a lattice…I think I’m gonna have fun with this 
. Thanks everyone. Stefano, I understand that the emitter will allow the particles to spread out, as they’re emitted from a convex surface, but how will that also confine them to the pipe? Or are you saying that after the animation–wait, no, that really didn’t make sense. I think I would still need to add a second emitter at the base of the pipe. Can you explain a little better?
Actually, I think it’s you who needs to explain better. Is this ‘pipe’ straight or convoluted, vertical or not? And why do the particles need to flow within the pipe? Surely, in a pipe it would still be a fluid body of water and only need to seperate into droplets (particles) on exit. I don’t mean to sound sassy, it’s just that I don’t have a clue of what the function of the ‘pipe’ is.
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I agree. Why do you want to tweak the real life?
In the real world, you have two forces. One pumps out the water and the other one, which is continuously affecting the water, is pulling it down (gravity) and maybe slightly to the side (wind maybe). Both can be simulated in Blender.
If you “pipe” is not transparent, you couldn´t see the water. If it is transparent, you wouldn´t see anything that moves in it (that´s what Fligh already mentioned)
I guess he want’s to use transparent pipes, otherwise this whole discussion would be kind of silly.
In the real world there are more forces acting then just the pump and the gravity, for instance a constraining force that keeps the water in the pipe and makes sure that the pressure created by the pump can be used to get the water to a higher level.
Maybe it’s a good idea to simulate the water in the pipe by using animated textures on the pipe.
and only use particles where the water leaves the pipe.
I guess he want’s to use transparent pipes, otherwise this whole discussion would be kind of silly.
That was my childish attempt to add some subtle humour to this discussion.
…a constraining force that keeps the water in the pipe and makes sure that the pressure created by the pump can be used to get the water to a higher level.
well… depends on what you actually look at. I don´t think we need to implement every property of a water molecule here. What I mean by forces are the vectors. One moves the water out of the pipe and one pulls it down.
Ahhhh. I shall try to explain better. Imagine a large, outdoor fountain made of glass. There is a central pipe that pumps water from the basin at the base of the fountain (where the water is caught after being sprayed up and out) back up to the top. I’d like to make it so that it starts with some water in the basin, then you watch as the water gets pumped directly up the pipe, finally emerging at the top. Hence, I want to use particles for the water in the pipe (so that when the animation starts you can see the liquid being pumped up) and then show particles spraying up and out of the top. Thus, just like in real life, the particles would be confined to the diameter of the pipe, then when they exit, they spray outward and upward. It would be fairly simple to model a rising water level in the pipe and when it hits the top, have a particle emitter start spraying outward, however, that was not the purpose of this thread. I really want to know if I can “contain” the water particles in the pipe, then have those same molecules spray “up and out” like a true fountain. This would have a number of applications for me, so this is why I have phrased it like I did. The fountain is more like an example, although it would be my first application of the idea of “containing” particles. I believe that the best way would be to use a lattice, but I didn’t realize that until just now 
. Thank you all for the replies. I shall do my best to utilize the knowledge gained here.
Yeah I see what you are saying and I think that you might have better luck using somthing other than partcals for the pipe. Maybe an animated mesh, or this could be a good chance to play with meta balls … depending on how long the pipe is and how fast your computer is (too many meta balls are a nightmare on a slow computer).
then at the top of the pipe kill the mesh/meta balls and make some cool looking particals (may I suggest using a nice texture for the particals :P)
Personaly I would make and animated cylinder for the water in the pipe and have partical emmited spheres for bubbles … make is look like the water is moving.
Just my thoughts
OK, clear as water! That’s what I thought and you could do that easily with two emitters, or with animated texture and one emitter. Trouble is, I’m sitting in a keep it simple paradigm and it seems others want to make it difficult as possible. . In the real world, if the water in the pipe is full of bubbles then the pump is causing cavitation and the fountain doesn’t work. But, hey, this is 3D, not the real world.
That ‘and’ function! If you set it to 0.000 keeps the column of particles confined to the emitted axis. Set that up and build your pipe around it. (‘Hash’ the emitter mesh to break the pattern) Then set your other emitter at the top of the first one and give it a positive ‘and’ value.
I don’t have the experience to give any advice on animated meshes or metaballs so I’m not knocking them, just telling what I know.
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actually, it’s “Rand”, not “and”. Just zoom on the button to see the R.
Martin
Exellent! That was the kind of concensus I was looking for. I will, in fact, use an animated column of water, probably with an emitter, just for looks. Then I will kill the column at the top and use a UV sphere emitter for the spray. Thank you so much. Gawd I love this forum!
Theeth wrote
actually, it’s “Rand”, not “and”. Just zoom on the button to see the R.
DARN!
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