Is PhoenixFD capable doing Simulations with GPU, CUDA, OpenCL?

[themaxxer]

Hi There

Long Time no posting from me... back again with another Question. I would like to know how PhoeniFD simulates scenes? Is it it withe the CPU or if possible with my Grphic Card and GPU? You have to know i am not very good in this. I would like to buy a new Grphic Card or maybe a whole Computer related to Simulations. Wich Card can you recommend? What is important for Simulations in general RAM, Graphic Card, CPU? Does PhoenixFD simulate the scenes like FumeFX, Realflow or does it use another Technique?

The Version i use for now is absolutely stable, a few Months back we had alot discussions about Problems with my Watefall Project. Do you remember? FLIP Simulations are the Best.

Is there any official Update to be released soon?

Thanks for your Help

Kind Regards David

[Svetlin.Nikolov]

Hey,

Currently the GPU is used only for the GPU preview - the simulation runs on CPU entirely. We have GPUs in mind, but this won't be coming into the nightlies soon.

There will be an official release with the FLIP solver, yes - we are clearing out issues and stabilizing right now.

Cheers!

[themaxxer]

Thank you for your quick answer. Sounds great. Then i have to spend my money in a more pwerfull CPU.

Another Question i have is what are the new parameters for... in the DYNAMICS Tab there is a "Simulate Air Effects" what does that mean? What is RGB Diffusion and Droplets Surfing? What is Wetting? Does it create Maps? In The FOAM Tab does "sticky still only work with B2B Interaction applied? What is Surface Lock? Do the Patterns now work with the FLIP Solver? In The SPLASH/MIST Tab what is CHAINING? Is it the same as B2B Interaction for FOAM?

Kind Regards

David

[Svetlin.Nikolov]

Hey,

Simulate Air Effects - should be used e.g. with mist and splash - it will simulate the air around the liquid so they would swirl more realistically.

RGB Diffusion should be used when mixing colors so that you don't get mixed dots of the colors that the particles were carrying.

Droplets surfing controls how long a particle slides on top of the surface before it drops in. Should be helpful with e.g. waves.

Wetting creates a particle wetmap over obstacles. Can then be shaded using the Phoenix particle texture which would allow you to blend a wet and a dry material.

Surface Lock controls how much the moving liquid affects the foam particles that are on top of it.

Sticky still needs B2B, Chaining is the same as B2B. Patterns should work with FLIP, yes

[themaxxer]

Thank you

This helps me alot in understanding the new Features (for me at least)

Bye

[victorwol]

so wetting does not keep actual particles sticking to the objects anymore? It is now only the wet map? Was the wet map always there?

Thanks

[victorwol]

Hey,



Droplets surfing controls how long a particle slides on top of the surface before it drops in. Should be helpful with e.g. waves.

)

On top of what surface? more liquid? or a solid that is collisioning on top too? because droplets are not supposed to drop into surfaces are collision against or resting on... unless you have a way to simulate porosity

[Ivaylo Katev]

Thank you for your quick answer. Sounds great. Then i have to spend my money in a more pwerfull CPU.

not at all, you have to spend money for faster hdd, ram, and bus. phoenix is not using the gpu not because we don't know how to do this, but because the calculations are not the weak point, the data transfer is.
depending on the scene, you can hit the hdd bandwidth, the ram bandwidth/capacity or the bus bandwidth, the cpu is hit only in very small simulations (about 1M cells), that are practically not used for production.

[Ivaylo Katev]

so wetting does not keep actual particles sticking to the objects anymore? It is now only the wet map? Was the wet map always there?

Thanks

the wetting does not just stick liquid particles to the objects, at least you can't use this in the rendering, but there are more reasons. the wetting produces separate particles, where the liquid was in contact with an object, these particles can "dry", i.e. they change their size with the time and you can use this in the rendering, and these particles can affect the liquid in two ways: by the sticky option and by the consume liquid option. the first one produces a force, the socond one changes the liquid amount, liquid disappears when wetting is produced.

[victorwol]

but in the past wetting was sticking liquid in place... I remember that, we discussed it.... so that option now is gone? Now they can only be used as part of a texture map?

So these wetting particles can't produce geometry now? like if you want droplets to stick to a surface and slowly come down like the droplets on the side of a cold beer bottle, how you would do that now?

[Ivaylo Katev]

now it does the same, but not by default, you have to specify "sticky"

[Svetlin.Nikolov]

Additionally, particularly for the beer drops - the wetmap now is a standard particle group like the foam and splash, so you could also shade it via PHXFoam as bubbles, points, fog.. in case your setup needs this.

[themaxxer]

Hi There

I have another Question? In the Splash/Mist Tab there is Foam on Hit...The "Depth" What exactly does this mean? In the Properties Tab i don't understand "Affect Liquid"? I also have Problems with "Resimulation" I don't know how to use it? When i simulate a Fluid without Splashes and Foam and afterwards... maybe after 200 Frames i would like to add the Splashes and Foam Max either Crashes or the Simulation starts all over again??? I also have a proposal. Wouldn't it be great to only produce Foam on Top of the Surfaces Mesh as a speedup for Quick Simulations? Do you know what i mean?

Kind Regards David

[Svetlin.Nikolov]

Hey,

From our beta-version of the new help:

Depth – When liquid surface is hit, this parameter specifies how far in front of the splash particle a foam particles will be created. This parameter is used mostly to create under water foam that will be colored by the fog color of the liquid.

Affect liquid - When nonzero, the splash birth causes liquid disappearing, and the opposite - deleting the splash liquid is created. When splash and mist are simulated with Affect liquid=1 they can be seen as part of the liquid simulation, because liquid splash and mist are constantly converted in each other.

For liquids, you basically use Resimulation when you want to keep the shape of the liquid that is already simulated once and tweak the foam, splash and wetting parameters. Could you attach a scene that crashes on you with resimulation? It's very important that we clear out such crashes. Do you have a problem when you set the start frame to 200 and resimulation stills starts from frame 0?

[themaxxer]

yes exactly, when i set the start frame to 200 it begins again from frame 0. maybe i do something wrong. but i don't know how to do the resimulation process. yes shure i can send you the scene. how can i do that?