The fluid in a square room, waste your life away simulator. My experience.

[alexglass]

I apologize if I come across as a disgruntled critic of the fluid sim, because after 30+ days of messing with this monstrosity that it is, I still cannot for the life of me get it to do what I want it to do. But through sharing my frustration and my experience with this thing I thought maybe I would help some of the newbies out.

For most of these simulations, due to domain size and speed of fluid, I was limited to a water resolution of 185 to 200. So keep that in mind when reading this.

My current simulation has the following settings.

domain size: 40x40x26, fluid real world size: .5(puroposely kept tiny)
inflows: 4 cylinders…2 x 9 units long, 2 x 1 unit long
inflows: 12 “droplet” inflows
outflow: deleted it after all.
obstacle: shell 39x39x25

First thing I wanted to do is a simple simulation of water flowing out of 2 curved pipes into a hole in the ground. Any resolution above 185 would absolutely crush a 1 year old laptop, not that it mattered since the fluid kept leaking through the curved pipes irrelevant of how many different shapes, wall sizes, I tried. In addition to that any water that flowed down into my water hole, would stubbornly not stick to any of the walls and instead kind of create a free standing conical shape.

TIP: Unchecking “remove air bubbles” in the domain panel could help prevent the water leaking through the pipes…some. Leaving it on makes the water extend and fill any shell type obstacle you are using and leaks through its walls. Problem is that turning off “remove air bubbles”, makes the water pretty much ignore the shape of your water hole. It just stacks on top of its self forming a cone of jello. How nice! Damned if you do, damned if you don’t.

In messing with it, I discovered that by designating a very large domain size(40x40x20) to a real world size of .5 in the domain panel, with an inflow speed of about 5, and pointing 2 cylindrical jets at each other, it would create this pretty awesome vortex jet splash that sprayed water everywhere and drenched everything.

Ok cool, so lets try to do an organic room that gets drenched in water.

ANYTHING but another demo of water in a square room you see on Youtube would be a plus at this point. As it turns out, there’s probably a reason that’s the only thing you see. The fluid sim pretty much breaks itself for anything other than that.

At first the room still had the water hole at the bottom, and even though the fact the fluid broke up in a million pieces did a better job of filling the hole at the bottom, there was so much water it completely overfilled it. It still looks cool, except for the fact that once the room overfilled above the hole, the water still radiated out from the hole edges to fill the walls of the room, despite the room being half filled with water! Huh.

Looks nice, except for the ring of water at the bottom that gradually extends from the overfilled hole to fill the sides of the room. Sooooo realistic…

Rule #1: Don’t make water holes inside a rounded room. Not to mention, it leaks through your hole anyway creating excess fluid.

Solution: Try an outflow to get rid of excess fluid?

It turns out an outflow only compounds the problem above, and on top of that, outflows have a mind of their own as well. Water will sometimes happily sit on one, go through it completely, and in other parts, will get deleted by simply being in its proximity.

Warning: An outflow MAY or MAY NOT delete water whether or not it touches it. There’s also little guide to how much water it actually deletes. At other times, the outflow will delete water that is simply in its proximity, sucking everything out in a split second leaving you with nothing in your entire room. Another 24 hours wasted…

So let’s remove the water hole and now we are back to a square room filled with water. Ok but a the very least I want a more rounded square room, with rounded corners and a bit of a bank to the lower part of the walls. “HA HA” said the fluid simulator. “I will completely ignore, as I see fit, when to allow water to pass through your rounded walls. Some of me will pass through it, while the rest of it will try to conform to the shape in the process making 3 underneath water surface layers underneath.” One that passed through the wall and conformed to the SQUARE shape of the domain. Another that was conforming on the backside of my rounded walls. And finally a third layer that actually did what it was supposed to do. Flipping normals? Subdivisions? Low polygon count? High polygon count? Don’t bother. Won’t make a difference.

Warning: Creating a room obstacle of a shape other than a cube will result in leakage!

Solution: You WILL have leakage! Accept it. Period.

Ok fine so we’re just going to have to scale the room at the end and meticulously get it to match up with the fluid. Next problem is that in 4 seconds of the jets blasting water, half the room is filled with water, so much so as the pipes are half submerged in water. Which wouldn’t be so bad, except for the fact that even if you set the inflow to a speed of 0, it’s still dripping fluid in the shape of a cylinder. So rather than getting the water to shut off naturally, you have a cylinder made of water on top of your water.

Ok fine, let’s animate the inflow, and make it leave the domain as its shutting off. That should fix it. Right? Wrong!

The water bubbles at the beginning of the jets are there simply due to adding an animation key on the inflow!

Warning: Simply setting an animation key on your inflow will completely change the shape of say -a cylindrical jet of water! It no longer looks like a cylindrical jet, but rather half of it deforms into a zillion particles, then magically straightens back up into a straight jet. All this just because you added an animation key frame, even IF you don’t actually change the location of your inflow. Animating the domain size also creates unexpected glitches and fluid simulation. PS: Whenever you see words like “unexpected” in relation to the fluid sim, don’t try it because it means you will waste hours and hours and hours baking and never figure out why it’s glitching!

Luckily since the jets straightened back out, the jets still smashed into each other creating my vortex of water. After baking the simulation for 2-3 days, I realized it was a bit too short, and I wanted to have more than just a standing body of water at the end. Maybe add a control object in the shape of a star fish coming out of the water. So let’s play with control objects.

Warning: To properly use a control object…HA HA HA!

The control object looked like absolute crap on a quality setting of 10 and 185 water resolution. On 11-20 quality it totally crashed my computer. On 20-50 and a water res of 200, it worked fine even if the required memory was now well over 1GB, would take 1 month to bake if I left it on, and before, it crashed at 300MB. Explanation??!

Despite bumping the water resolution to 200, and the quality of the control object to about 30, the control object’s resolution was still horrible even with simple shapes. In fact, the water itself was nice and smooth, but the water making up the shape of the control object looked as low res at a resolution of 200 as at a resolution of 85. Same for a quality of 10 or a quality of 30.

Solution: Just don’t use it. 3 days wasted.

I gave up on it and decided to just have a regular jelly fish swimming through my room of water. Except, I was still not happy with the size of the water bubbles, and wanted finer water bubbles as the jets blasted it everywhere.

You might suggest turning on tracer or drop particles. As you can see they are there. Of course, the problem is in such a simulation, the simulator gets COMPLETELY confused and after the water settles, half of your particles are frozen mid air. Useless.

Warning: Using tracers or any other particles in a water jet, vortex room simulation will completely confuse the simulator. The water will settle and half your particles will remain frozen mid-air!

I also tried using a combination of fluid particles and dynamic paint along with my fluid sim.

Rules:
-You CAN use the fluid simulation to paint with dynamic paint and create wet maps.
-You CAN create ripples using dynamic paint right on top of your fluid simulation if used as a canvas even though they are subtle and require a high water resolution.
-However, even though you can use dynamic paint to generate vertex weight maps right on your fluid sim, you cannot use the fluid sim as a particle obstacle or generator to create the extra splashy effects. (Since the particles sims no longer have reactive particles… this is really needed.)
-You may or may not be able to use the vertex weight map, to generate particles. You CAN use it to control the LENGTH of hair particles, but so far, I have not been able to figure out how to use the vertex weight maps created with dynamic paint to generate particles from those locations. BUMMER! If anyone knows this answer, please, please let me know!

So I decided to simply bump up generate particles in the domain panel to get my smaller bubbles and more splashes from about .4 to 1. Guess what? It took 3 days to bake and now my room is barely filled 1 quarter of the way.

Warning: Increasing generate particles from about .4 to 1, will literally result in DOUBLE the water loss when it settles!!!

And despite me removing a small outflow, increasing the duration of my inflows, as I typed this I am on DAY 3 of the SECOND time I tried baking this fluid simulation only to find out, I’m getting the same result in terms of water loss. A day and a half to go. My jellyfish is done, but it won’t be swimming int this freaking square room!

Thank you and Dear Fluid Sim,

I hate you.

[K_Horseman]

It’s hard to tell from this what exactly you were trying to create, since none of your screenshots show the space you were trying to fill with water. It’s also hard to tell what your obstacle meshes were like from this description. Were you using proxy meshes with extra backside thickness as your obstacles, or just your regular rendered room mesh? Cube shape versus any other shape has no effect on fluid penetration through obstacles. That problem is usually caused by a lack of proper thickness in the obstacle.

Also if you are just trying to show water pouring out of pipes into an existing pool of water, there are better ways to accomplish that effect than by using a fluid sim for the whole thing. It’s rarely a good idea to use a single fluid simulation for a large, complex fluid-like system no matter what software you’re using. You can, for instance, use an ocean modifier and dynamic paint to create the pool of water, then composite in separate renders of fluid sim water coming from the pipes. That’s just one method off the top of my head; there are no doubt other and better ways than that.

TL;DR version: don’t try to make any single fluid simulation do more than one or two things. Three if you’re very experienced and talented and have a very good computer. Sitting in a pool counts as one thing. Draining out of a hole counts as one thing. Pouring out of one source counts as one thing, and you list 16 inflows in one simulation. Use tricks and compositing if you want to do more than that. Attach your .blend file if you want us to take a look and suggest specific ways to make your scene work.

[alexglass]

@K Horseman

It’s hard to tell from this what exactly you were trying to create, since none of your screenshots show the space you were trying to fill with water. It’s also hard to tell what your obstacle meshes were like from this description. Were you using proxy meshes with extra backside thickness as your obstacles, or just your regular rendered room mesh? Cube shape versus any other shape has no effect on fluid penetration through obstacles. That problem is usually caused by a lack of proper thickness in the obstacle.

Also if you are just trying to show water pouring out of pipes into an existing pool of water, there are better ways to accomplish that effect than by using a fluid sim for the whole thing. It’s rarely a good idea to use a single fluid simulation for a large, complex fluid-like system no matter what software you’re using. You can, for instance, use an ocean modifier and dynamic paint to create the pool of water, then composite in separate renders of fluid sim water coming from the pipes. That’s just one method off the top of my head; there are no doubt other and better ways than that.

TL;DR version: don’t try to make any single fluid simulation do more than one or two things. Three if you’re very experienced and talented and have a very good computer. Sitting in a pool counts as one thing. Draining out of a hole counts as one thing. Pouring out of one source counts as one thing, and you list 16 inflows in one simulation. Use tricks and compositing if you want to do more than that. Attach your .blend file if you want us to take a look and suggest specific ways to make your scene work.

To your suggestion. There is little reason to break up this fluid simulation into multiple ones, because it’s incredibly simple. The jet vortex is part A, the water settles into the room is part B.

The pipe objects actually have no effect on the simulation as they are completely out of the picture and not used as any sort of obstacles. I had to give up the idea due to all the other problems and I’m simply retreating them by frame 1 as if they were a shooting gun.

It really is nothing more than 2 cylindrical inflows shooting water at each other, and settling into a rounded room. That’s all there really is to it. If I split it up and use an ocean modifier then you’re not going to have the drops deform back into a fluid. Which is basically the point. Especially since the simulation will freeze mid-way showing the suspended droplets of water, before speeding back up and falling to the ground.

The additional 12 inflows are nothing but tiny spheres of water droplets that only turn on after the fluid settles which are meant to create additional droplet splashes from the ceiling at the end and don’t have any effect on the problems above.

Of course as it finished I realize the leakage will completely ruin any underwater scene as part of the underneath and side layers have conformed to the original cubical domain shape…

But if I go back and create a -wait for it- CUBE - room exactly the shape of the domain…it looks like an underwater scene…

The amount of scaling required to surround the outside layers of the fluid with the walls of the room, would push the room past the original boundaries of the domain(due to the inward, curved corners). Which wouldn’t be a problem for the underwater part, but you would clearly be able to see it separate from the fluid when looking from above. I wanted to dip the camera underwater. Not to mention, even if I scale, you can still notice the layers where it tried to conform to the shape of the room.

And yes I can create a thicker room obstacle, however, I don’t see how that’s going to help with this problem as it would still leak through the interior wall, and would still create additional layers. I thought that by keeping it thin, it would make the scaling job at the end easier and help me deal with the inevitable leakage.

But now…I’m all out of ideas and feel defeated.

PS: I tried uploading the blend file in a new reply multiple times but for some reason the upload fails.

[K_Horseman]

Your collision objects need to be thick, which often means using an extra proxy object that isn’t rendered. Are you doing that, or are you just making the visible objects your obstacles?

Use pasteall.org to post your .blend.

[alexglass]

Believe me, thickening was the first thing I tried and it just wasn’t an option for me.

I only have the room as my obstacle, and no it is single sided and not thick. Just what you see and that’s mainly due to a few issues. For one I simply cannot afford to scale the domain size in either direction, by more than perhaps a few fractions of a blender unit due to the memory requirements or the actual settings required for the scene. I have refined it and refined it to come to this size/speed/resolution settings in terms of what my laptop is capable of doing.

The way the animation is planned out with the camera coming in from the top-down, in order to get a view of both pipes initially acting like guns shooting fluid, it can’t be any wider without having to raise the ceiling as well in order to move the camera further away. Scaling the room/domain results in memory and processing issues. Also I have it fit so tightly and exact that if I scale the room inwards to add thickness, it means shortening my inflows, which can really affect the shape and size of the initial vortex being created by the jets. I had to place them a specific distance/speed apart from each other, as well as the domain walls, to get a nice circular vortex. And that took days and days of baking to get the settings just right. I’m at the very limit of what my laptop can do in terms of resolution and memory.

Anyway, I did manage to come up with a new solution that might help others running into this issue.

By scaling the room inwards just on the underwater section to hide the visible edges of the underwater fluid, and use a duplicate of the room, invisible, along with dynamic paint to create a new layer of water in the shape of the walls, gives me the underwater look while still keeping the original top surface of the fluid untouched. Haven’t finished it yet and still have to animate it to see how it looks, but I figure this is basically going to be the only way.

Here’s the result:

Before:

After:

Using a transparent, fluid colored layer in the shape of the room, scaled slightly, and placed on the interior(dynamic paint is necessary in order for it to match up properly with the animated edges of the surface of the water. You can then add an IOR effect, bump mapping, etc as you wish.)

Above water:

For now this will just have to do. I don’t have the patience for another 5-days-long bake. Been at this for a month. I’m just shocked that something so simple gives so many problems and requires so many workarounds. All this because I wanted rounded corners instead of a cube.

Not to mention I also really can’t thicken the obstacle all around. I need to use a combination of the obstacle and the sides of the domain itself as obstacles. I’ve tried using the entire room as an obstacle and what ends up happening is you get fluid that gets stuck to the sides of the walls and jiggles like jello. Not all droplets fall back down. The only way I found to prevent that from happening at this resolution is to use the domain walls as your obstacles for everything except the rounded part at the bottom and corners. So the center of my walls are actually on the outside of the domain. And no it is not leaking at the intersection. This seems to actually work ok. It’s leaking about a foot below that for some strange reason.

Trying to get smooth layers with the simulator in an organic shaped room just isn’t going to happen at a 185 resolution. And bumping it up any more than this, at least on my laptop, is not an option. The vortex is highly highly intensive. I’ve managed to bake at resolutions of 300+ and with memory requirements of 1G+ in other scenes. But anything over 185 on this scene will just cripple my laptop. To give you an idea, at 185 with generate particles on 1 it takes 5 days! A 200 resolution takes about 10-15 days…which is just crazy. Anything above that just crashes.

Thank you for your time and suggestions. Sometimes all it takes is just explaining my problems to someone who listens in an A-Z fashion and just jotting them down and then it seems to help come up with the idea for the solution. Btw, if you have any idea how to use dynamic paint weight maps to generate particles from those locations(not hair), I would really appreciate it.

[K_Horseman]

Yeah, it sounds like a lot of the problems are happening because you aren’t doing obstacles correctly. Like I said, I could offer some better solutions if you post your .blend so I can see exactly what you’re doing. Your descriptions aren’t enough.

[alexglass]

I got it uploaded. You’re more than welcomed to check it out.

http://www.pasteall.org/blend/20926

[Kaluura]

I downloaded your file and the first word that came to my mind was “insane”.

No wonder that you need years to bake any fluid simulation. Your geometry is insane. Fluid simulations are CPU-heavy processes… and they use only one CPU core… So, when you throw tons of geometry at them, they crawl. That’s to be expected.

The very first thing to do is to re-build a very simplified “waterroom”. Pretty (and heavy) things in fluids simulations must stay out of the way until the very last second before you render. You’ll see, things will get much better with less geometry.

[alexglass]

I have already explained the purpose of the inflows above. They’re there to simulate water droplets from the ceiling, and yes they were added way after the initial phase was complete.

As I have explained, I’ve already found a solution to the issues I had as far as the underwater part goes. And yes while the amount of geometry may seem insane, notice only the bottom of the portion of the room and curved corners are actually used for the fluid simulation. The ceiling, floor, and exterior walls are actually outside the domain(for reasons I have already explained), thereby not really adding anything in terms of processing.

The high polygon count however helps create a very smooth and natural edge around the walls.

The reason for the high calculations is the actual vortex and the thousands of water bubbles flying everywhere and interacting with each other, not the room object. The simulation actually moves quite fast once it gets pats that initial phase. You can attempt this with no obstacle at all, and it will still crawl due to the bursting jets.

Guys I have been at this for over 30 days and I appreciate your help though from your suggestions I don’t think you quite understood some of the problems. I’m way beyond adding thickness or simplifying things. Thickness and simplification were the two things I tried on day 1…over 30 days ago. I wish it was as simple as that. I’m way beyond running a marathon here. I’ve already performed over 30 variations of this simulation and I arrived to where I arrived now by seeing what worked and what didn’t.

[K_Horseman]

OK, I’ve made some major changes to just get the basic functionality of this simulation working. We can build on the other things you want later.

1. Drop all the keyframed motions and velocities and other craziness. Make the basic simulation work first. Don’t do everything at once, or none of it will work.

2. Use Ctrl-A to apply scale. You haven’t done that to anything in here, and that is a basic first step you have to take in any simulation. You say you’re way past all this stuff, but you haven’t done it at all. Did you know you need to do that?

3. Your fluid simulation needs to stay inside the domain. That includes everything that’s a part of it. Don’t put stuff outside. You have obstacle objects that are bigger than the domain. You have inflow objects outside the domain. You have things poking through the side of the domain, half in and half out. It all needs to go inside. You were complaining that your fluid wouldn’t conform to the shape of the space you wanted it, and was just coming out a “big square room.” Well yeah, because your domain was smaller than the space you wanted your fluid to occupy, it ran up against the domain walls instead of the tank or whatever this thing is. This is another thing you should know if you’re way beyond anything.

4. Obstacles need thickness. Lots of it. You say you’re way past this too, but you haven’t done it. These objects have zero thickness. Use the solidify modifier for this, cranked way up. Make them simple if you can, or your simulation will misbehave.

5. It’s best to accomplish this by making a proxy object. Duplicate the object you want to look like it’s your obstacle, turn off its renderability, stick it on another layer, put on a solidify modifier with a negative value to give it outside thickness, apply the solidify modifier, then make it an obstacle.

6. The water dripping from the ceiling A) can be accomplished in a simpler way that doesn’t make the simulation more complex, like with a particle emitter, and B) should be added after everything else is already working properly. Which it isn’t yet. Slow down and take this one piece at a time. Don’t add extra junk to something that doesn’t work, or you’ll just have more stuff that doesn’t work.

7. The “waterroom” object really doesn’t need to be so complicated. It’s just a smooth cube with rounded edges, but it’s made of 29,000 faces. It looks like you did a dynamic topology sculpt on a cube, just to get a slightly rounder cube. You could accomplish this by subdividing a cube once or twice and putting a subsurf modifier on it. This kind of unnecessary complexity is part of what’s making it so hard for you to get the results you want.

8. Why are there keyframes on the domain’s alpha value and speed? What fluid behaves that way? Seriously, I have no idea what you’re really trying to make here. Water? That’s not how water works. Those are just more extra complications that make it harder for you to get the basics working.

9. The real reason for all the insane splashing that’s got you so bothered is that you have the fluid particles set ridiculously high. Cut them out completely for now, wait until you’ve got the effect you want, then bring them in at a reasonable level.

I’ve read back through your descriptions, and it really sounds to me like the problem isn’t the fluid simulator, it’s attention deficit disorder. You saw it do one cool thing, a vortex effect, so you tried to make that thing cooler, then that didn’t work so you tried to do something else to it, then that got frustrating so you tried to change something else. You’ve got all these weird, weird attributes keyframed, and there are motions that don’t really make any sense to me because I don’t know of anything that behaves that way. There’s a tank with a couple of “guns” that move around and shoot water for some reason. You mention something about maybe putting a fish in it. There’s not a clear story here, it just seems like you’ve been tinkering with on effect after another because they seem cool. But never in that chain of distractions did you make sure that the most important basic steps had been taken to get this to work from the start. You need a step by step plan before you start a project like this. Slow down, plan ahead, build this in pieces, and make sure each piece actually works before building the next one.

And remember, in studio vfx, you rarely want to build a complete simulation of the system you’re filming. You build just what you need for the shot, then you do the next shot. You make reusable parts of course, but there’s no need to have a constant simulation going with water dripping from the ceiling and all this other complicated stuff if you’re just going to do an underwater shot that won’t see any of that, for instance. With this many cameras in the scene, it’s clear that you want to do some shots that will not benefit from this simulation at all. Plan those out and build for them, or you will just drive yourself crazy.

You’ve spent 30 days making this much more difficult than it needed to be. From looking at this it doesn’t seem like you have done enough simple simulations to have a clear understanding of how they work, or you wouldn’t have done things like leaving fluid objects outside the domain. That’s what I meant when I said you’re trying to run a marathon before you can walk. Try something simple like water pouring from one glass into another, and get that looking absolutely perfect before you try something even approaching this.

Take a look at this version, bake the simulation, see what it’s doing now. It won’t produce the absolute final result you want, but it should give you a firmer starting point to build on and a clearer idea of how things are supposed to work. WaterYouDoing.blend (217 KB)

[alexglass]

I truly appreciate you taking the time to do all that but as I said before, I assure you I have already done every single step you outlined already before I reached this final setting. I told you I spent the past 30 days on this scene, and you honestly believe I didn’t try a beveled cube? Look, most of the solutions you offered, I have already tried and said so in my initial reply but I don’t think you took the time to read it in the first place. And as I already explained, and showed you above, I have already fixed the problem I had. So thanks for your help but it’s all good now.

However, I will argue with you on a couple of points cause I feel you’re insulting my intelligence a bit. For the last time, thickness will not do anything for the problem I have outlined above. My issue was not leakage. It was the actual layer between the fluid and the side of the wall, which when viewed from underneath the water didn’t look accurate due to some of it penetrating the obstacle wall. A thick obstacle, from my experience, will still allow leakage through the first interior wall. So thickening the obstacle may prevent leakage, but it doesn’t help create a smooth intersection layer. I could care less about the leaked fluid.

So even though you have a double sided cube the fluid layer will still not adhere smoothly enough to the interior cube wall which is the one that was causing issues. Heck you can make it 10000 times thicker or have 30 layers of walls, and it won’t fix that problem.

So it’s useless in my case. Scaling does not fix this either. As long as it’s not a negative value. It’s irrelevant in this case.

Also at this resolution, using a combination of domain walls and obstacle, at this resolution, was the only way to prevent random fluid particles from sticking to the walls like jello. Objects DO NOT have to be entirely in the domain, despite what other guides say. I have performed many tests and they work good enough in most cases coming in from outside the domain. Your cube will still have fluid sticking to the sides of the wall after the vortex settles. Sure if you use a resolution of 400+ above you might get there, but try baking this fluid simulation at that resolution on your typical laptop with only 4GB of ram and I promise you your thick obstacle will be just as worthless as mine was when I did it. For whatever reason, that doesn’t happen when it hits the domain walls so that was the only workaround I could find.

And yes I have performed many, many simple fluid simulations to get to these workarounds.

I can also see that you are completely obsessed with animation keyframes that have absolutely nothing to do with any of the issues above. The only one that causes an issue is that animating an inflow can change its shape in the fluid simulator. It’s a bug. No way around it. The pipes do not move around, except when they stop pumping in fluid. This isn’t some crazy effect as you imply, but rather, it was the only way to simulate an inflow pipe shutting off…

And while its good to keep the obstacle simple, it needs to have enough faces in order to smoothly pull only the center of the walls OUTSIDE the domain object(for the reasons I just explained above) and give me a nice curved corner around the room. But again the only thing that’s really intersecting with the fluid are the smooth corners. So the rest of the geometry doesn’t actually get involved in the simulator.

I truly think you believe I just slapped a scene together with some geometry, and that’s not the case at all. It may look like I’m not following “the basics” but I’ do know them, and if I am not following them is because I had to break some rules in order to get close to what I want to achieve.

As far as the particles I already explained I initially used less particles. I started on .4 And yes I WANT 1! I want them all…Why? I have already tried particle systems with dynamic paint…and yes it’s a nice effect…

But this can’t be replicated to the level that I want since you also cannot use the fluid simulation as a collision object. So since you can no longer replicate the effect of small bubbles splashing in the water with particle systems, as of right now I can’t find a better way of doing this in Blender than my 12 little inflows at the end. Again, if you would have read, you would know why I had to bump up the particles to 1. On .4, .6, you just don’t get enough small bubbles at this resolution. They’re big. The actual floats, and tracers that are part of the fluid sim are totally useless because the sim gets confused and they don’t follow the water post-vortex. Some of them get stuck mid air. So those didn’t help either.

The reason I didn’t want to post my Blend file is because I didn’t want to confuse anyone with issues that bear no relevance on the problems I am having nor did I want anyone critiquing unfinished work. The alpha value animated once again has NOTHING to do with any of the problems listed above. But if you’re simply curious…

you could just ask. My scene will be a bit more complex than just water and it’s not shooting for realism. And this undergound wateroom in itself is actually part of a much larger animation on a sort of artistic alien landscape scene. It’s probably 20% of my overall animation. So you are critiquing something that isn’t even finished yet.

Again I really appreciate you taking the time to do all that for me, but if you would have read a bit, you would have know it’s something I have in fact already done or considered.

[K_Horseman]

Like I’ve said several times, the main problem here is that you’re trying to create a single huge simulation that does a ton of things instead of just doing what you need for a shot. You’re confusing getting an overall effect that is perfect from every angle with getting a single shot that looks right. All you really need is something that gives you the single shot you want.

Layering on all these animations and motions and inflows and other things just makes it harder to get what you really want. You really ought to break down your planned animation into individual storyboarded shots and figure out which shots truly need a full simulation, which shots could be accomplished with a simpler simulation and some compositing tricks, which shots might need multiple simple simulations composited together, and which shots could be done without any simulation at all. Sticking a handful of cameras into a single huge simulation is only going to cause you grief, because this is just not what the simulator is designed to do. Think of it this way: when making Jurassic Park they could have made full-body self-contained robot Brachiosaurs. Instead, they made a single 7-foot tall Brachiosaurus head puppet and just got the shot they needed. For everything else they used other small animatronics or cgi creatures. This simulation you’re trying for here is that full-body robot. You’re trying to make the fluid simulator do things that it isn’t designed to do, and complaining that it can’t do them.

You say you’ve done all these things I suggested, but you haven’t even done simple things like apply the scales of your objects. That’s a basic thing that you just have to do, period, but you seem to be unaware of it. I’m sorry if you feel like I’m talking down to you, but you’re just doing things incorrectly on a very basic level and then insisting that you know better anyway. If you have fluid sticking walls, for instance, there are settings in the simulation to change that specific behavior. Do you know about those, and do you know how to use them? Because you’re not putting them into practice here either.

I’m not trying to critique your unfinished scene, I’m critiquing your practices. You’ve cobbled together something very complicated before you even have the basics working, and then you’re complaining that the whole thing doesn’t work. You just can’t do things that way. You have to take this one bit at a time and make each thing work in turn before you add something else that also doesn’t work, but your file has about 20 things that each individually don’t work. Most of those cases are just because you’re not doing things the way they are supposed to be done. Yet you’ve argued in your latest post that the documentation itself is wrong, despite the facts that A) you’re not following that documentation properly and B) your project doesn’t work properly.

I know you’ve put a lot of hard work into this, and I’m not trying to insult your intelligence. If I just thought you didn’t get it, I wouldn’t bother explaining anything to you. I’m just trying to make you see that you’re putting a lot of unnecessary obstacles in your own path, and I’m trying to help you get rid of those.

[alexglass]

Here I created a Youtube account just for you and uploaded an older barebone version(with particles generate set on .4) of what I’m trying to accomplish. You keep talking about simplifying it…

I’d love to hear how you plan on simplifying this scene any more than 2 cylinders and a box.

And I know all about scaling the objects, placement of objects, etc. I’ve done both, researched, and experimented myself. I have reset the scale before. They’re not in the file I showed you because after doing this simulation 10 zillion different ways, scaling didn’t have an effect on any of the problems I was having. As long as it’s not negative, it just didn’t impact it at all. I get that you are a stickler for correct practices, and I do understand them, but it just didn’t have an impact.

And yes the non-slip setting is on 0. As I already stated. But as I said, I’m good with it because using the domain walls worked just fine to get rid of them but it did require I break one of the so called “rules” and placing parts of my obstacle outside the domain object. This was also necessary in order to maintain straight jets to create the vortex(the proximity of the backside of the jets with the domain wall compared to using the room obstacle created different type of jets physics especially when placing an animation key on the inflows(which is a known bug)…the other part of it being due to the remove air gap option…which I can not turn off if I want my fluid to create a nice, close edge around my room and then use the fluid to create wetmaps and paintmaps in dynamic paint). When I attempted to use a room obstacle and placed the jet in close proximity, the jet immediately began disintegrating into many particles and lost its cylindrical shape before colliding with the opposing jet. Using the the domain wall didn’t do this despite me leaving the air gap option checked.

My final issue was the leakage causing an uneven layer, which resulted in part of the walls of the room being in FRONT of the side, fluid layers. That resulted in the underwater illusion, and water “haze” getting broken. And this is just not going to get fixed at that resolution. So I had to use dynamic paint and an additional room object to fake it.

I have come to the conclusion the simulator simply isn’t capable of creating a smooth enough fluid/obstacle intersection layer at a resolution of 185 because of inevitable leakage or unless you use a very basic object like a straight edged cube. And no amount of scaling, thickness, etc, will change that.

Look don’t feel you were not any help, because you were. As I said, your interest alone in my problem and me breaking it down to explain it was enough to make me see it from a different angle and come up with that solution. But I think you are ragging on things that have no effect on the issues I was having.