A fast simulation of flowing liquid in a trough or mold

I want to “reasonably simulate” a liquid that is being poured into a trough or mold of arbitrary shape, e.g. a channel sculpted into a mesh plane.

I don’t want to spend hours on a fluid-simulation.

I’m free-thinking about some kind of effect that uses metaball-particles. I can sort-of describe what would be needed according to solid-body physics rules, as though the metaballs were, say, little heavy marbles. I don’t mind using Blender Game-Engine and bullet and so-on.

So, I am basically looking for what might be easiest and what might be already done. “Boids,” for instance? It does not have to be photorealistic; the folks are not going to be admiring the beautiful fluid-shapes; there will be no “droplets.” I know that I can do it by laboriously hand-animating shape keys in a mesh.


Actually, I think a fluid simulation would be the fastest way to do that.
Unless you have an old system that can’t handle fluid sim very well, I would say to give that a shot.

The only other reason that might not be a good approach is if you want more exact control over the “liquid”. in which case, playing with metaball particles might be a good solution.

I agree that fluid sim sounds like the way to go. Metaballs quickly get really heavy to work with in my experience. If you have just a quick spray of liquid, then you could do particles with plain spheres of water, but for what you’re looking for, it sounds like fluid sim would be easier and faster than metaballs.

Well, I cheated. :slight_smile: But I think it looks pretty convincing. (You’ll all get to see, soon.)

Here’s what I did…

  • The mold is created by a mesh that has been sculpted. - The “flowing liquid” is another mesh that’s positioned below the mold, such that the sculpted lines in the mold poke through it. When you see the part that is above the mold, it looks like it’s in the mold. - There’s a lot of animated-texture going on… changing the color and the normals so it looks like the fluid is heaving. - There are a series of relative shape keys, where I literally pushed the fluid shape so that it pokes beneath the mold, starting at the end of the pour and working backward, key by key, until nothing shows through. In the final animation, the IPO runs backward. - The “pouring iron” from the ladle is a separate effect, formed by a gusher of particles flowing through a lattice … and actually disappearing beneath the fluid-layer although it doesn’t look that way.
    The whole goal of this piece is simply to illustrate what happens in the molding process, not to depict it. I don’t need physics-accuracy and don’t want to invest the time obtaining it.

I plan to post a draft animation of the scene in a couple of days, and I’ll post more info about how I did it if anyone turns out to be interested.

when looking for advice like this it could be useful to tell us what kind of hardware you are working one as I am unsure what kind of technical advice to give you. On a modern system on a recent blender build you could just do a fluid sim as other people have suggested.

if not, you can do what Mpan did a couple years back with textures on his website to simulate stormy ocean water and modify it some I guess