I've got no "easy article" to begin with.

But just think about it. What is there to a particle
program? You need particles, definetely. They move
around, so you'll need to know their positions, keep
track of their speed. Some way of detecting collisions
with other objects (using trace(), probably, or 3D-algorithms
with input from user). You'd probably head for I/O on
a frame by frame basis, so there is a need for Output
and Input from and to disk.

I came up with my version of a particle-system about a
year ago, and its non I/O. Some animations can be found
on my webpage (recently added a new one), but I guess
many people know this already (I mean that I've done
a P.-S., not the animation).

But for mass-particle and such, you can probably find some
PDF files floating in the web, mostly scientific and not
"easy-rating"...

Hugo wrote:

> > instead of everybody rolling there own particle systems, how about we club
> > together and cook up the ultimate be all and end all of pov particle
> systems
> > .... just a thought
>
> Agree! I'd be willing to cooperate, but I'm not that good in math.. Let me
> know if I can help anyway.. Even just the sharing of ideas between more
> people would probably be good.. I wonder, maybe SDL is not the final
> solution, but a step towards coding in C and expanding POV's native
> abilities, starting with Pov4.. It could also be important for us to know
> how much is going to change in Pov4; if there are already people considering
> this. But anyway, it's not too early to start now.. Rune will soon be
> releasing his particle system, and we know it's going to be good..
>
> But is there an easy article on the net, that I should read to understand
> more of this stuff?
>
> Regards,
> Hugo

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html
Email: Tim### [at] gmxde

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I do like the idea of creating a Particle-Team,
but I also like to do stuff on my own.
It depends on how fast the team is
going to fall apart, and how good we
cooperate.

But we could create something "open-source"
like. I'd be willing to cook up some basic
rules for Macro-Definitions inside the
system (though I should have some help to
make sure that everything is taken care of)
and supply/write some fundamentals.

I'd be happy to host the system and keep
track of an "official" version, e.g. I'll
check additions and look at the algorithms
(as long as they're commented good enough).

If there more than just a bunch (I'd say at least
10), send a reply here and I could go on
and create a page for our OpenSource-PS.

"Rick [Kitty5]" wrote:

> instead of everybody rolling there own particle systems, how about we club
> together and cook up the ultimate be all and end all of pov particle systems
> .... just a thought

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html
Email: Tim### [at] gmxde

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Hi!
> How it could be done? Probably with some sort of
> n-body-algorithm, with adaptive time-steps, good
> approximation for hundreds of particles, springs...
Yes, that's exactly what I meant. Leap frog is just some kind of Runge Kutta
(which is also a numerical solution to differential equations), but it's
faster and it's reversible. I have programmed (as most physic students) a
Runge Kutta of order 4 to simulate planetary movement. Later we have used
same algorithm for gas simulation with 100 particles. But Leap Frog should
be better for this purpose for speed reasons. Any forces should be possible.
>
> A lot of stuff, so probably not be coded in pure
> POV. *sigh*
I would prefer external program in C. Also for speed reasons.
Thanks for reply,
Florian

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> I do like the idea of creating a Particle-Team,
> but I also like to do stuff on my own.

Me too. But I never tried a little team-work in this way, so I'd be willing
to give it a try, without getting very obligated.. Thanks for explaining the
basic principles of a particle system, it sounds logical, but also I'm sure
I'll do so many things wrong, if I just start coding. Probably I'll start
reading more about it, if I can find something simple.

Regards,
Hugo

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Tim Nikias wrote:

> This is cool. Someday, I'll write a particle-programm which can
> do that... Until then... *sigh*

Theoretically, my paricle system can do strings, cloth, and gels, however it
would
be a very slow process because it would not be optimised for this purpose. I can
do this because I have a user defined force within my system. I might give this a

shot just to see...

MJL

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Tim Nikias wrote:

> I do like the idea of creating a Particle-Team,
> but I also like to do stuff on my own.
> It depends on how fast the team is
> going to fall apart, and how good we
> cooperate.

I feel much the same.

> But we could create something "open-source"
> like. I'd be willing to cook up some basic
> rules for Macro-Definitions inside the
> system (though I should have some help to
> make sure that everything is taken care of)
> and supply/write some fundamentals.
>
> I'd be happy to host the system and keep
> track of an "official" version, e.g. I'll
> check additions and look at the algorithms
> (as long as they're commented good enough).
>
> If there more than just a bunch (I'd say at least
> 10), send a reply here and I could go on
> and create a page for our OpenSource-PS.

Sounds like a good idea. Count me in.

MJL

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"Hugo" <hua### [at] post3teledk> wrote in message
news:3cce861a$1@news.povray.org...
> But is there an easy article on the net, that I should read to understand
> more of this stuff?
>

http://www.darwin3d.com/gdm1999.htm#gdm0499

has some cool c source code with exe's for this sort of thing

jim

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What gives the residual strains? Do you have plasticity built in or is
it a side effect of your algorithm?


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

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Peter Popov wrote:
> What gives the residual strains? Do you have plasticity built in or is
> it a side effect of your algorithm?
>

Peter, you haven't been paying attention. :)
He is using a commercial program to generate the coordinates for the
particles and I'm 95% sure he has no clue of the algorithms the program
uses. Neither do I.

--
-Jide

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"Jide" <jid### [at] kotisoonfi> wrote in message
news:3cd058ae@news.povray.org...
> Peter, you haven't been paying attention. :)
> He is using a commercial program to generate the coordinates for the
> particles and I'm 95% sure he has no clue of the algorithms the program
> uses. Neither do I.

Make that 99.999% :-) I haven't a clue.. certainly wasn't expecting the cube
to remain deformed, but pleasantly surprised with the results.

Andy Cocker

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