[ODE] Particle/cloth/skeleton (was: Re: Choleski factorization)

[amundbørsand]

<david@csworkbench.com> skreiv:
[..]
>  If you want to make a person, you implement
> them as a normal rigid body setup.  If that person, however, happens to be
> Batman, you attach a particle-based cloak to strategic points on his rigid
> body torso, and it would flap around when he ran.  Or you could have a
> flag attached to a rigid body pole, add a little random "wind" force to
> each particle, and watch it flap in the wind.  Or you could allow your
> characters to climb ropes, that actually swing like a rope should, without
> all the added computations that small bodies with ball joints between them
> causes.  The particle system wouldn't replace the rigid body system, but
> augment and provide functionality it just can't do.  The more I think
> about it, the more I realize I could just use the tri-collider or some
> other particle, stick, and triangle collision functions with the normal
> collider, and integrate the verlet integrator into every iteration of the
> algorithm I'm working on, and have great interaction between rigid and
> soft bodies, both ways.

Sorry to barge in, just had to inject my two cents: :)

A "cloth"-simulator is a lot of fun. But I would think it has more to do
with rendering and visual effects than physics, and a cloth simulation
isn't physically accurate either, in the form ODE is, in my opinion. Fun?
Yes. Accurate, physical, useful for all users of ODE (not just Batman
creators)? No, I don't think so. But it would be nice to have a "plug-in"
package available for download for use with ODE, but it may not need to
be distributed with ODE as a default.. ?

However, particle-to-primitive (and mesh)-collision would be very nice.
So can people go from there.

Also, I've been thinking about strings, that's something that ODE lacks.
In my physics class we always have to do a lot of simple computations
with strings (although stupid, friction- and massless and mostly
one-dimensional, it seems to be used quite often). I've always wanted to
make a game/simulation which included cranes (is that a usable English
word for it? You know, things that lift things), and I found that the
biggest problem was really how to make the wire act realistically. It
would be exciting to add that into ODE (elastic and non-elastic strings,
for instance. Verlet or not, I don't know how to do it best).