Fluidos. Show me the honey! (A thread for all things liquid.)

Richard Haseltine

The cell size change has to be cubed to get the increase in number of cells, which (if my numbers are right) have given 3 min 19 sec for the 1.5 cm cell and 1 hr 19 min 35 s for the 0.5 cm cell if it was the only factor - so obviously there are other factors too. I went down to a 1cm cell size in one of my tests, which didn't seem too bad (took about an hour-and-a-half, but that included particles). I didn't try rendering it though.

Havos

Richard Haseltine said:

The cell size change has to be cubed to get the increase in number of cells, which (if my numbers are right) have given 3 min 19 sec for the 1.5 cm cell and 1 hr 19 min 35 s for the 0.5 cm cell if it was the only factor - so obviously there are other factors too. I went down to a 1cm cell size in one of my tests, which didn't seem too bad (took about an hour-and-a-half, but that included particles). I didn't try rendering it though.

Indeed you are correct, and that was my calculations as well. 0.5 is 5 times smaller than 2.5, but would include 125 (5x5x5) times as many particles. This roughly fits in with my figures, which means the number of particles is the critical factor in time needed, but no doubt if I had had a more complex environment than a cube for the cells to interact with, that would have also pushed up the simulation time. 

linvanchene

Is the plugin able to use more than one GPU to calculate the simulations?

If yes, is there an option to choose which GPUs are used and which are free for other tasks?

Havos

linvanchene said:

Is the plugin able to use more than one GPU to calculate the simulations?

If yes, is there an option to choose which GPUs are used and which are free for other tasks?

No, it only uses one GPU, and barely uses that. You can also not select the GPU at the moment, I guess it uses whatever the system says is the default GPU.

After a struggle with drivers etc I got my 1080Ti working with Fluidos, but it did not make a dramatic difference to the simulation times. Most of the time the GPU is doing very little whilst the one thread used by the plugin runs flat out. On the bright side there is plenty of room for future improvement as the plug-in is not currently using all the hardware available to it, but hopefully improvements will be made.

Alberto

v1si0n4ry said:

I just can't make it work with human figures, like tears or water splashing on face.... Shame, I feel like I wasted money

This is the setup of the tears image:

There are a FLUIDOS Domain, two Sources and one Sink (to remove water out of the bottom). The Domain is small to get better resolution whitout large simulation times.
The tears come from spherical sources. No velocity is applied to them, the liquid flows by gravity (a small one). The figure only has to be parented to domain; by default, is managed as obstacle.

Right tear

Left tear

The sink:

Alberto

Havos said:

I have done some testing using different cell sizes, to see how much it varies the look and simulation time.

As a test I simulated a simple scene with a source of water pouring onto a cube and cascading off the edge. No sink is included, so the water accumulates inside the Fluidos domain.

I tested 3 sizes. 2.5 (the default Fluidos loads with), 1.5 and 0.5. The simulation times for a 120 frame video were:

Cell Size 2.5:  43 seconds

Cell Size 1.5: 4 minutes 26 seconds

Cell Size: 0.5 5 hours 26 minutes!

As you can see the time needed for the best quality simulation was pretty heavy. However in my opinion it looks far better, and the only sim where the water looks like water, rather than frozen ice. This was run using GPU mode, but the reality is Fluidos only uses the GPU for a part of the work, and it also only uses 1 thread for the CPU work, so likely as not most people's PC's would get a similar time as me for the same work. The three full videos are attached if anyone wants to watch them. Only 4 seconds, but enough to appreciate how the water flows for each cell size. 

Here are the links to download the videos

https://www.dropbox.com/s/a8jnrl8rygld1wa/Pour-CellSize0.5.mp4?dl=0
https://www.dropbox.com/s/va57a7eohhbg3og/Pour-CellSize1.5.mp4?dl=0
https://www.dropbox.com/s/ak9e0uz2lc1mljb/Pour-CellSize2.5.mp4?dl=0

 

It could be beneficial to enable Diffuse particles in Domain Properties (and to add another Mesher with diffuse particles enabled).

kyoto kid

Havos said:

linvanchene said:

Is the plugin able to use more than one GPU to calculate the simulations?

If yes, is there an option to choose which GPUs are used and which are free for other tasks?

No, it only uses one GPU, and barely uses that. You can also not select the GPU at the moment, I guess it uses whatever the system says is the default GPU.

After a struggle with drivers etc I got my 1080Ti working with Fluidos, but it did not make a dramatic difference to the simulation times. Most of the time the GPU is doing very little whilst the one thread used by the plugin runs flat out. On the bright side there is plenty of room for future improvement as the plug-in is not currently using all the hardware available to it, but hopefully improvements will be made.

...so it sounds like the CPU carries the brunt of the load. Too bad that more CPU cores couldn't be applied to the sim.  Would make those big Threadrippers more attractive.

I wonder if the Tensor cores in the forthcoming 20xx cards (and current Titan-V) might not help with the sim as they are used for just such calculations.  That may be a selling/buying point.

Kitsumo

I added Fluidos to i13 Sento. Link goes to the thread with description.

 

kyoto kid

..very nice.  I have that same set.

Diomede

That is excellent!

Kitsumo

Thanks. I'm slowly getting better with Fluidos.

Alberto

Kitsumo said:

I added Fluidos to i13 Sento. Link goes to the thread with description.

 

Your simulation is very good!

Kitsumo

Alberto said:

Kitsumo said:

I added Fluidos to i13 Sento. Link goes to the thread with description.

 

Your simulation is very good!

Thanks a lot. And thanks for the recent update.

Diomede

Has anyone successfully created a Fluidos preset that can be shared as a freebie?   I have a couple of ideas and would appreciate not having to reinvent the wheel.  I am referring to creating a prop like a garden hose that someone could add to their scene.  Are there Studio file collection and arrangement issues unique to Fluidos, or is it like any other freebie?

Subtropic Pixel

Nice, all nice!

Alberto

Diomede_Carrara said:

 Are there Studio file collection and arrangement issues unique to Fluidos, or is it like any other freebie?

It's like any other. The only difference is you have to add the .state file.

I, myself, am creating a series of Fluidos presets. This is the first one:

More: https://www.daz3d.com/forums/discussion/310366/coming-soon-fluidos-presets-series-commercial#latest

 

Paradigm

Anyone know why the fluid always seems to want to follow the intitial "x" orientation of the source object? I give the fluid a Y or Z velocity it'll always go to the X. But if I rotate the sim -90 Y it'll go forward the direction I choose. But the first frame will do a little... spurt? to the same initital direction every time.

Alberto

Paradigm said:

Anyone know why the fluid always seems to want to follow the intitial "x" orientation of the source object? I give the fluid a Y or Z velocity it'll always go to the X. But if I rotate the sim -90 Y it'll go forward the direction I choose. But the first frame will do a little... spurt? to the same initital direction every time.

Could you show  a snapshot of the Fluidos properties of the Source, please?

Paradigm

https://i.imgur.com/iPTF70k.jpg

I also includes the weird spurt in the direction after a couple frames.

I've also run into another issue where I got a simulation done and merged the scene with an existing scene, then parented a character to the domain so it would interact with the liquid but the liquid ignores it (even if I choose body force).

 

Alberto

Paradigm said:

https://i.imgur.com/iPTF70k.jpg

I also includes the weird spurt in the direction after a couple frames.

I've also run into another issue where I got a simulation done and merged the scene with an existing scene, then parented a character to the domain so it would interact with the liquid but the liquid ignores it (even if I choose body force).

 

For your source, set the Velocity (x) to 0.0 (the default is 100.0),

About the second scene, try to use a lower cell size, because low resolutions aren't suitable for figures.

Let me know if the above don't work.

Paradigm

Hi Alberto, thanks that did work. I'm a dummy. I just assumed all the Velocities would be defaulted to zero. I'm having a lot of fun playing with the tool and it's really impressive to see it directly inside of Daz. 

Two more questions:

1. Is the intent that the Velocity is an initial speed coming from the source and the domain forces are gravity and the like? I'm trying to figure out how to create a fountain stream and I think that's how it would work.
2. Is there a way to get the fluid cells to cling together a little more? I tried briefly to make a really viscous liquid and ended up kind of getting something like a machine gun of melty tapioca balls lol

Alberto

Paradigm said:

1. Is the intent that the Velocity is an initial speed coming from the source and the domain forces are gravity and the like? I'm trying to figure out how to create a fountain stream and I think that's how it would work.

Yes,  but you can change the velocities and the forces values. The values could be zero or negative either. For a fountain you need to set the source Velocity (y) to a positive value, maybe 300 or more. In fact, there is a Fountain recipe in Fluidos documentation (it's in ReadMe's folder, "54155_fluidos-recipes-guide.pdf") or here: http://docs.daz3d.com/doku.php/public/read_me/index/54155/start

 

Paradigm said:

• Is there a way to get the fluid cells to cling together a little more? I tried briefly to make a really viscous liquid and ended up kind of getting something like a machine gun of melty tapioca balls lol

Increase more the viscosity. The scene of the figure walking on snow uses 500,000 as viscosity value for simulation.

See here the video:

In next image you see the snow after the figure walked. 

In the same documentation above there is an example of honey too.

kyoto kid

...so I wonder if you could turn it into sand as well.  The one thing that ruins desert and beach scenes, no footprints (or if there's a vehicle, tyre tracks) in the sand.. 

Alberto

kyoto kid said:

...so I wonder if you could turn it into sand as well.  The one thing that ruins desert and beach scenes, no footprints (or if there's a vehicle, tyre tracks) in the sand.. 

Yes, you could; the only difference would be the shader.

Paradigm

Consider me blown away. That snow is a fluid? Outrageously cool.

 

I missed the fact that there is a PDF of recipes. I guess I know what I'm doing tonight! 

Dartanbeck

I use Carrara, and here is my first try with Fluidos for Carrara

I plan to do a lot more with it - my computer died on me (six years old already? Sheesh!) Must build a new one!

Luv Lee

mrinal said:

Alberto said:

mrinal said:

Blender already has water simulation and there are tons of tutorials on youtube for that. Can someone explain what can be achieved through this that cannot be already done in Blender? This is of course assuming that it shouldn't be difficult to import the water plane after simulating it in Blender.

Whitewater feature in FLUIDOS:

In this frame there are more than two millon of diffuse particles.

Blender MantaFlow already has particle simulation. So how different is it from MantaFlow? Is it going to be more efficient computation-wise to support 2 million particles? Sorry, but the image alone doesn't priovide a fair explanation.

Here's the ManaFlow status in Blender 2.79.1:

 

How about I have used Blender, not a fan of it, and I like being able to have dynamcs and particle phsycs in my platform of choice...?

Luv Lee

Artini said:

mrinal said:

Blender already has water simulation and there are tons of tutorials on youtube for that. Can someone explain what can be achieved through this that cannot be already done in Blender? This is of course assuming that it shouldn't be difficult to import the water plane after simulating it in Blender.

The biggest advantage for me, is that simulations are done inside Daz Studio, so one can easily use Daz assets with them.

I will not probably use it for making animations, but mostly for static renders, though.

 

Same. I have used Blender for some things but prefer the ease of use of Daz, especially since a lot of what I do is time sensitive and adding to the workflow pipeline by using another program is just not reasonable. Ease of use is a good thing, nothing is gainned making things harder or by something taking longer.

Luv Lee

Dim Reaper said:

I bought Fluidos and then discovered an immediate obstacle - apparently you can't just download and install it, you have to use DIM, which not everyone does.  After wasting some time looking for the installers, I finally relented and downloaded and installed DIM, then finally got Fluidos installed and working.  After that minor annoyance, I have to say - "Wow!"  This is an amazing plugin, with a lot of possibilities.

After a few practise runs, I rendered an animation (first time for me in Daz Studio), and then rendered a couple of stills at better quality.

 

 

Do'h,  I can't wait to get my hands on Fluidos but yeah DIM is a pain, it glitches a lot on my end of things and doesn't always work well. Still, I will endure the pain for this--did you find the learning curve steep or...?

Luv Lee

FirstBastion said:

Good functionality inside DazStudio.  Delivers expected results quickly and efficiently. Tutorial is straightforward on what's required for setup. Since I've used blender fluids before so already had basics down. Going to get good use out of it. Its important to support PAs that introduce new inventive products. 

 

I agree with everything you said and love the latter part of your reasoning -- we really need to support PAs who deliver these kinds of elemnts so that they keep bringing dah pain!  I am always excited when someone offers these kinds of plugins.