> I know of 2 web pages on the subject:
> Hugo Elias's page(look under "Mass & Spring models"):
> http://freespace.virgin.net/hugo.elias/models/m_main.htm

That's the one I used.

> Xavier Provot's page, with some techniques which can fix some of the
> problems with the method demonstrated on the page by Hugo Elias:
> http://www-syntim.inria.fr/syntim/recherche/provot/index-eng.html

I got the texts but haven't reviewed them yet, the web site seems abandoned,
though.

> I am planning to do a POV patch which can do something like this, but
> generalized to work with strings and gels as well as fabric.
>
> As far as the problems with your attempt...could you be more specific?
> Do you mean "unstable" as in it crashes, or does the simulation just
> become chaotic and go out of control?

It becomes either chaotic or too stretchy, but sometimes both. There should
be a sweet-spot between the two, but if the gravity isn't very very small it
vanishes, the result turns out super-stretchy *and* chaotic.

On Elias's site some spring psuedo-code goes:

    ForceScaler = (Length - NormalLength) / (Length * Length) * SmallAmount

If I change the gravity, or the amount of particles, I need to change
SmallAmount, I think there's got to be a better formula. I also can't see a
logical reason to divide by Length twice, and I see SmallAmount as a kludge
anyway.  I'd like to create a model which works independant of the particle
count and gravity, where each could be changed without the end result
becoming unrealistic.

I think I need to do some research and come up with a better algorithm,
basically one that conserves energy and limits stretching to a minimum (or
none at all).

> Did you add a drag amount?

I'm not sure what you mean, like air-resistance? If so, then no. It's a very
limited model right now.

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