filling a shape takes for ever...

Discussions about the use of Realflow 3
CapitanRed
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filling a shape takes for ever...

Postby CapitanRed » Thu Aug 30, 2007 9:17 am

hi...sorry if I ask a stupid question, but I can't find the right solution.

I'm trying to fill up a mesh, but it took me now 3000 frames and it still didn't fill 1/10.
I know that i can increase the speed of the emitter, but then the fluid gets pushed out to havy and splashes on the ground to much. I need a natural water tap simulation.

could it be my scene size settings? now it's on 0.05. but as i remember one square is 1m in realflow, and my mesh is in real life about 10cm. so i think it the scene size should be that small.
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ChristianZ
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filling a shape takes for ever...

Postby ChristianZ » Thu Aug 30, 2007 10:23 am

Hi !

A help, at least for me, is the display of the (brown) grid in RF's viewports. With this grid I made a rule of thumb for my sims: I know, that if my glass or container is about 1-5 squares big, I will have no problems to fill or do other sims with it.

Apart from the sizes, the other parameters for the fillling speed are density and pressure settings, but I assume you know this already.
RF10 standard + RFC4D

CapitanRed
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filling a shape takes for ever...

Postby CapitanRed » Thu Aug 30, 2007 3:23 pm

so, i setted the scale up, so the mesh is about 5 squares.(to 0.075 :P...not a big change)

hmm...i know this settings, but they didn't help me. my fluid should be havy and slow, like some caramel or glue. but this would mean high density. but when i set the density higher, doesn't then the particles may get nearer to each other? like a smaller collision distance.( this is how i understood it from the manual)
I tried to set it very low(75), but this makes them splash extremly. and if the value is high, the fluid is very thin on the floor and takes long to fill up.

same thing for the pressure. if the external pressure is high, or same as the internal one, it takes long to fill up, and if it is lower than the internal, it splashes around.
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shaun_michael
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filling a shape takes for ever...

Postby shaun_michael » Thu Aug 30, 2007 4:02 pm

Can you post all your emitter settings please?

The higher the density, the heavier the particle, at the same resolution. The setting that allows particles to collide more closely with one another is the internal pressure setting.

As I say, it would really help if you could post your settings.

Which 3D application are you using, and can I just confirm you are using Realflow 3 yes?

Shaun

CapitanRed
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filling a shape takes for ever...

Postby CapitanRed » Fri Aug 31, 2007 8:57 am

sure, I can

-3d app is 3ds max
-RF3
-scenescale 0.075

Emitter settings:

scale x,y,z: 0.3

Resolution: first 10, but this was to low i think. now it is 100, but it simulated now 450 frames and didn't fill even the floor.

density:100000
Int Pressure: 0.9
Ext Pressure: 0.1
Viscosity: 8
Max Particles: 2'000'000

Currentframe 455, and there are 236600 Particles

Volume: 0
Speed: 2.75
V random: 1
H random: 0.1

The higher the density, the heavier the particle, at the same resolution. The setting that allows particles to collide more closely with one another is the internal pressure setting.

I think I missunderstood some settings here :P

Thank you both very much for helping me
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swag
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filling a shape takes for ever...

Postby swag » Fri Aug 31, 2007 9:41 am

density:100000 ?

try something like 1000

the scenescale ist very small too

CapitanRed
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filling a shape takes for ever...

Postby CapitanRed » Fri Aug 31, 2007 9:54 am

so, do you think that if I scale down the mesh in max first, or change the unit setup, and then import it into RF, it would work better?
because, if I make scale higher, the object goes very large in RF
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zorcad
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filling a shape takes for ever...

Postby zorcad » Fri Aug 31, 2007 10:00 am

hi,

You can try one other things that I used in maya a lot. If your scene is huge you can scale down it in your 3d application (3ds Max) and then import it in RF; as you know decreasing the scale in RF doesn't give you good visual results.

As I have learned, in RF you don't need to increase the internal and external pressure more than 1 or at least 2. Just play around with values greater than 0 and less than 2. And for fluids like water what you can do is make the external pressure lower than the internal. like internal 2 and external 0.8.

Yes you are right, that is a problem of filling huge containers in RF that you can't increase the speed of the emitter as the fluid will splash out of it and other problems.
Its natural as RF simulates the objects in the scenes, in real life it happens in almost the same way.

-zorcad
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shaun_michael
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filling a shape takes for ever...

Postby shaun_michael » Fri Aug 31, 2007 10:55 am

My advise would be to either model in Max to RF scale (so that you're looking at a model, in RF, that occupies no more than about 1 to 2 grid squares at a scale of 1.0

Or import your object into RF, set the scale to 1.0 and then, within RF scale your object down to fit into 1 - 2 grid sqaures at it's base - you should then be able to rescale both geometry and mesh (if necessary) back in Max.

Your settings, for caramel or some such in RF should have a relatively high viscosity, 8 should be fine to start with, densite say 2000, int 0.1, ext 1.0, add a little friction to your collision object, and gravity at about 15-20. At least that's where I'd start off, and tweak from there.

Dont forget, thats all at a scale of 1.0 though.

Shaun

CapitanRed
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filling a shape takes for ever...

Postby CapitanRed » Fri Aug 31, 2007 2:47 pm

thank you guys for the suggestions.

i scaled the mesh first in max and then again in realflow, as it still was little bit to big. now it matches 2 squares on a scene scale of 1. I also changed the fluids properties.

due to the scale i had to scale the emitter too to 0.1 and increase the resolution to 400. the simulation is "slow" now, and is at frame 385. 40'000 particles and the floor is still not covered by the fluid. :glare:

I think i'll let it simulate over the weekend and see what happens.
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