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this and I've been trying to use the parametric equations way because that
is what the spiral can be defined in. I get stuck when it comes to doing
the integrals in PovRay. I don't even know if you can do integrals in
PovRay. Thanks for any help. :)
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Of course you can do integrals in POVray. You can do anything with POVray.
*Fanatical glint in the eye*
You can obtain a numerical approximation of the integral by applying its
definition, i.e. take a very small dx, evaluate y and add dx*y to previous
sum in the loop.
You can also use the generalised hypergeometric solution, see
http://mathworld.wolfram.com/CornuSpiral.html The generalised
hypergeometric looks like a nasty customer to code, but it has the
advantage of being an exact solution.
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Is there a way to evaluate the integral with a different program, transfer
that information to a file (a txt i guess) and have Povray read it from
that text file in order to animate a path for a sphere?
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In article <web.466495c47064b1ed998929610@news.povray.org>,
"Joe" <Pre### [at] aolcom> wrote:
> Is there a way to evaluate the integral with a different program, transfer
> that information to a file (a txt i guess) and have Povray read it from
> that text file in order to animate a path for a sphere?
hum... just a try :
x=0
y=0
for i=1 ... n
t=eval(fn)
x=cos(2.pi.t)
y=sin(2.pi.t)
sx=sum(x)
sy=sum(y)
draw point at <xs,ys>
for cornu spiral fn => i^2/321
not tested :)

klp
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"Joe" <Pre### [at] aolcom> wrote:
> Is there a way to evaluate the integral with a different program, transfer
> that information to a file (a txt i guess) and have Povray read it from
> that text file in order to animate a path for a sphere?
Yes, definitely, POVray can read ASCII text files, see 3.2.2.3 in the
documentation that comes with POVray (for Windows). For some reason the
same topic is numbered 2.2.2.3 in the online documentation:
http://www.povray.org/documentation/view/3.6.1/238/
If you make a search for "Handle" on the newsgroup, you should obtain some
really good examples of reading/writing ASCII files.
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