I've made an elastic cube (a cubic grid of spheres connected with springs).

I've posted a version of the source to povray.binaries.scene-files. It 
basicly shows an animation of the cube falling down on a surface.

Unfortunately, the thing itself has serious "bugs". In the animation you'll 
see that the springs seem to "lose strength", which seems unnatural. 
(Render the scene and you'll see what I mean.)

Another, more serious bug is that if you rotate the cube before dropping 
it, it simply falls apart after hitting the surface. (A somewhat similar 
problem arises if you try to "pull away" one of spheres.)

Right now I don't really know the cause of these problems. Please help.

--

Gergely

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Gergely Vandor <ger### [at] moravia-itcom> wrote in
news:Xns### [at] 204213191226: 

<snip>
> 

Oh, I hope you won't tell me that someone has already done the exact same 
thing much better. :)

--
Gergely

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On 1 Apr 2002 10:45:59 -0500, Gergely Vandor
<ger### [at] moravia-itcom> wrote:

>Oh, I hope you won't tell me that someone has already done the exact same 
>thing much better. :)

Err... quite a lot of people, actually :)


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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Peter Popov <pet### [at] vipbg> wrote in
news:k3jhauouekul0fja6lbmi892rcp96ipmop@4ax.com: 

> On 1 Apr 2002 10:45:59 -0500, Gergely Vandor
> <ger### [at] moravia-itcom> wrote:
> 
>>Oh, I hope you won't tell me that someone has already done the exact
>>same thing much better. :)
> 
> Err... quite a lot of people, actually :)
> 

My search engines seem to fail me this time. :) Could you please point me 
to some post/website about spring systems/elastic objects etc. made with 
povray? I've found only a couple of posts about springs here, and no 
animations or source.

--
Gergely

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I don't know if this is helpful but:
    http://www.darwin3d.com/gdm1999.htm#gdm0499

has some applications and the full c source code for this sort of thing.
There's a cloth mesh made of springs and I think the particle dynamics one
is similar as well.

jim

"Gergely Vandor" <ger### [at] moravia-itcom> wrote in message
news:Xns### [at] 204213191226...
> Peter Popov <pet### [at] vipbg> wrote in
> news:k3jhauouekul0fja6lbmi892rcp96ipmop@4ax.com:
>
> > On 1 Apr 2002 10:45:59 -0500, Gergely Vandor
> > <ger### [at] moravia-itcom> wrote:
> >
> >>Oh, I hope you won't tell me that someone has already done the exact
> >>same thing much better. :)
> >
> > Err... quite a lot of people, actually :)
> >
>
> My search engines seem to fail me this time. :) Could you please point me
> to some post/website about spring systems/elastic objects etc. made with
> povray? I've found only a couple of posts about springs here, and no
> animations or source.
>
> --
> Gergely

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"jimbobjim" <jim### [at] blueyondercouk> wrote in
news:3caa1ed0$1@news.povray.org: 

> I don't know if this is helpful but:
>     http://www.darwin3d.com/gdm1999.htm#gdm0499
> 
> has some applications and the full c source code for this sort of
> thing. There's a cloth mesh made of springs and I think the particle
> dynamics one is similar as well.
> 
> jim
> 

This is simply great. :)

Though not PoV-Ray related, it gives some very useful general info about 
spring systems, not to mention the cool apps.

Big thanks, jim! :)

--
Gergely

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Check my clothing experiments at http://geitenkaas.dns2go.com/experiments/.
Those sheets are exactly what you're talking about: just a bunch of
particles, interconnected with lots of springs.
I'm working on a new version (on and off, I'm a bit busy nowadays) that is
capable of cloth/jelly/spunge interaction with csg objects (union,
difference, merge, box, sphere, torus, cone, cylinder, and maybe maybe
triangle mesh or even blob).

--
Apache
http://geitenkaas.dns2go.com/experiments/
apa### [at] yahoocom

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"Apache" <apa### [at] yahoocom> wrote in
news:3caa5720$1@news.povray.org: 

> Check my clothing experiments at
> http://geitenkaas.dns2go.com/experiments/. Those sheets are exactly
> what you're talking about: just a bunch of particles, interconnected
> with lots of springs. I'm working on a new version (on and off, I'm a
> bit busy nowadays) that is capable of cloth/jelly/spunge interaction
> with csg objects (union, difference, merge, box, sphere, torus, cone,
> cylinder, and maybe maybe triangle mesh or even blob).
> 

Pretty cool, is the source available? :)

Meanwhile it seems I've found the basic problems with my springs. Here's a 
basic anim. The springs are pretty stiff this time, so it behaves almost 
like a solid cube.

http://www.progressive.hu/gero/drum.m1v

--
Gergely

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I wrote the thing in C, although I started in in pov-ray script. But that's
too slow for this kind of mathematically heavy duty stuff. Especially with
spring objects containing 300x300=90000 particles with even more springs....

And I absolutely love your simple animation, because the movement is really
realistic IMHO.

--
Apache
http://geitenkaas.dns2go.com/experiments/
apa### [at] yahoocom

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Apache wrote:
> 
> I wrote the thing in C, although I started in in pov-ray script. But that's
> too slow for this kind of mathematically heavy duty stuff. Especially with
> spring objects containing 300x300=90000 particles with even more springs....

The obvious solution is doing it as a Povray patch.  You have the
adventages of fast compiled code and have access to the internal shapes.

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 18 Mar. 2002 _____./\/^>_*_<^\/\.______

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