POV-Ray : Newsgroups : povray.binaries.animations : Re: Fluid-like simulation (MPEG1) Server Time
20 Jul 2024 03:32:48 EDT (-0400)
  Re: Fluid-like simulation (MPEG1) (Message 1 to 7 of 7)  
From: Mahalis
Subject: Re: Fluid-like simulation (MPEG1)
Date: 16 Nov 2001 16:37:15
Message: <3bf5870b$1@news.povray.org>
Very nice for a first try, but it looks like the particles aren't losing an
energy with each bounce.

--

//Mahalis
camera{location<0,0.25,-2> look_at 0.5*y} #declare T=texture{pigment{crackle
scale 0.5 rotate 90 turbulence 0.75 color_map{[0 rgb 1][0.05 rgb 1][0.1
rgb<1,0.25,1>][0.25 rgbf 1][1 rgbf 1]}} finish{ambient 1}} #declare
c=difference{torus{0.5,0.1 rotate -90*x}box{<0.7,0,0.2>,<-0.7,-0.7,-0.2>}}
merge{object{c translate<0.5,0.5,0>} object{c translate<-0.5,0.5,0>}
cylinder{<1,0.5,0>,<1,0,0>,0.1} cylinder{<-1,0.5,0>,<-1,0,0>,0.1}
cylinder{0.5*y,0,0.1} texture{T}}
--



news:3bf5514e@news.povray.org...
> This is the first time I post an animation here. I was amazed by some of
> your liquid animations and decided to try to make my own.
>
> First I tried to drop the "liquid" from above the surface, but I
encountered
> many problems, and decided to try first with the liquid already touching
the
> surface. Then I gave the particles an initial angular velocity, I think it
> looks better.
>
> I think it still needs more blobs...
>
> Any commentaries are appreciated.
>
> Fernando Gonzalez del Cueto.
> Mexico City.
>
> ps. The surface is sometimes known as the mexican hat function :)  f(x) =
> cos(x^2 + y^2)
>
>
>


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From: Rune
Subject: Re: Fluid-like simulation (MPEG1)
Date: 16 Nov 2001 17:31:07
Message: <3bf593ab@news.povray.org>

> This is the first time I post an animation here.
> I was amazed by some of your liquid animations and
> decided to try to make my own.

This is a very good start! But it looks like it's going in slow motion, so
I'd suggest speeding it up a bit. That could also help get the file size
down a little...

I also suggest you try to add some more randomness to the initial velocities
of the particles.

> I think it still needs more blobs...

When simulating liquids you *always* need more blobs - always! Hehe, that's
just the way it is... ;)

I'm looking forward to see the next animation from you!

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated Nov 5)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk


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From:
Subject: Re: Fluid-like simulation (MPEG1)
Date: 16 Nov 2001 18:28:07
Message: <3bf5a107$1@news.povray.org>
"Mahalis" <don### [at] fakeycom> wrote in message
news:3bf5870b$1@news.povray.org...
> Very nice for a first try, but it looks like the particles aren't losing
an
> energy with each bounce.

Thank you! Yes, I also think that the friction coefficient that I used was a
little bit too low. But one can imagine that the surface is made out of
Teflon(R)!!! :)

Currently I'm making another experiment. I hope I can finish it today...

Fernando.


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From:
Subject: Re: Fluid-like simulation (MPEG1)
Date: 16 Nov 2001 18:31:03
Message: <3bf5a1b7@news.povray.org>
Thanks!!! I am already working in another experiment... Let's see if it
works!!! I hope I can post the results later today.

Fernando.



"Rune" <run### [at] mobilixnetdk> wrote in message
news:3bf593ab@news.povray.org...

> > This is the first time I post an animation here.
> > I was amazed by some of your liquid animations and
> > decided to try to make my own.
>
> This is a very good start! But it looks like it's going in slow motion, so
> I'd suggest speeding it up a bit. That could also help get the file size
> down a little...
>
> I also suggest you try to add some more randomness to the initial
velocities
> of the particles.
>
> > I think it still needs more blobs...
>
> When simulating liquids you *always* need more blobs - always! Hehe,
that's
> just the way it is... ;)
>
> I'm looking forward to see the next animation from you!
>
> Rune
> --
> 3D images and anims, include files, tutorials and more:
> Rune's World:    http://rsj.mobilixnet.dk (updated Nov 5)
> POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
> POV-Ray Webring: http://webring.povray.co.uk
>
>


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From: Greg M  Johnson
Subject: Re: Fluid-like simulation (MPEG1)
Date: 19 Nov 2001 13:02:32
Message: <3BF948C0.3897E9C1@aol.com>
I think this would be even more cool with a tweaked surface so the center was up
a little bit higher.



> This is the first time I post an animation here. I was amazed by some of
> your liquid animations and decided to try to make my own.


Post a reply to this message

From: Dennis Milller
Subject: Re: Fluid-like simulation (MPEG1)
Date: 20 Nov 2001 20:23:02
Message: <3bfb01f6@news.povray.org>
Hi. I am very interested in your fluid simulations, though I would like to
try to use something similar in my own abstract animations. Can you tell me
a little more
about how you create and them and perhaps show me some code that I might try
to experiment with?
Thanks very much for your help. By the way, is that your real email, by
chance? My original email to you.bounced back
Best,
Dennis




news:3bf5514e@news.povray.org...
> This is the first time I post an animation here. I was amazed by some of
> your liquid animations and decided to try to make my own.
>
> First I tried to drop the "liquid" from above the surface, but I
encountered
> many problems, and decided to try first with the liquid already touching
the
> surface. Then I gave the particles an initial angular velocity, I think it
> looks better.
>
> I think it still needs more blobs...
>
> Any commentaries are appreciated.
>
> Fernando Gonzalez del Cueto.
> Mexico City.
>
> ps. The surface is sometimes known as the mexican hat function :)  f(x) =
> cos(x^2 + y^2)
>
>
>


Post a reply to this message

From:
Subject: Re: Fluid-like simulation (MPEG1)
Date: 20 Nov 2001 23:53:44
Message: <3bfb3358@news.povray.org>
Hi Dennis!

I know that the real fluid theory is based on the Navier-Stokes equations,
but I think they're really too complicated to be implemented easily in POV.

I'm actually using a trial and error method and trying to see what looks
good. My latest experiment (which I hope I can post later, if it finishes
soon and looks good!!) is based in a gravity simulated environment, in which
there is no interaction between particles. Actually I tried using some
interaction detection routines, but the simulation was WAY TOO SLOW...
especially for a large number of particles.

Then I've implemented a function (which I call "embarrar", which is more or
less like "spread" in Spanish), which gives me the new direction of the
particle when it collides with the surface.
First I used a angle-of-incidence-is-equal-to-the-angle-of-the-reflection
routine, but it bounced too much and it really didn't look like a liquid.
(Even though it looked cool sometimes!)

But now, the new vector of direction depends on the angle of incidence in a
new way: if it is orthogonal to the surface, then it will spread out on the
surface. If it is not orthogonal, then it will be a weighted average between
this random spreading vector and the true reflection vector, weighted by the
angle between the incidence vector and the normal vector of the surface.
I don't know if I'm making myself clear, but remember I'm developing all
this stuff by trial and error, so I really don't have a solid theory backing
my algorithm.

I'm writing my code in Matlab, which exports a textfile with the blob's
coordinates, and then POV reads these textfiles.

Maybe I can show some of my code later, if you still are interested.

Fernando.

ps. Yes, my email is modified so it won't be taken by spam bots. If you see,
YAHOO has 3 o's in the address.


"Dennis Milller" <dhm### [at] mediaonenet> wrote in message
news:3bfb01f6@news.povray.org...
> Hi. I am very interested in your fluid simulations, though I would like to
> try to use something similar in my own abstract animations. Can you tell
me
> a little more
> about how you create and them and perhaps show me some code that I might
try
> to experiment with?
> Thanks very much for your help. By the way, is that your real email, by
> chance? My original email to you.bounced back
> Best,
> Dennis
>
>
>

> news:3bf5514e@news.povray.org...
> > This is the first time I post an animation here. I was amazed by some of
> > your liquid animations and decided to try to make my own.
> >
> > First I tried to drop the "liquid" from above the surface, but I
> encountered
> > many problems, and decided to try first with the liquid already touching
> the
> > surface. Then I gave the particles an initial angular velocity, I think
it
> > looks better.
> >
> > I think it still needs more blobs...
> >
> > Any commentaries are appreciated.
> >
> > Fernando Gonzalez del Cueto.
> > Mexico City.
> >
> > ps. The surface is sometimes known as the mexican hat function :)  f(x)
=
> > cos(x^2 + y^2)
> >
> >
> >
>
>


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