I now have a working Chaos Pendulum - yay!

But I was wondering... how would I go about modelling air resistance? All I
want is to have a system which doesn't go into a fixed oscilation that lasts
forever; I want air resistance to damp it down.

Let's say I have a vector V which represents the particle's velocity. I
could do something like
  #declare V = 0.9*V;
Or perhaps I could try
  #declare V = pow(V, 0.9);
(if that would actually work - POV-Ray's syntax won't allow it, but you get
the gist. Something like "pow(vlength(V), 0.9) * vnormalize(V)" would work -
or even "pow(vlength(V), -0.1) * V".)

The question is, does air resistence slow something down more at high speed?
Or is it roughly constant? (I know this depends on the shape of the object -
we're talking about a smallish sphere here.) Clearly a high-speed object
will encounter more drag. But it will also have more momentum. So which is
it? Multiply V by a constant 0 < k < 1? Or raise it to the power of a
similar constant? I'm not really interested in making this super-realistic,
I'd just like some opinions.

Thanks.
Andrew.

Post a reply to this message