Ron Parker wrote:

 <snippage>
>find a better PRNG for 3.5, since we've all seen some of the bad results
>you can get from the current one.

        I am curious: "bad results?"  Is the povray generator *that*
bad?  I mean, I have not done a rigorous statistical analysis of the
random output but it seems as good (as bad?) as any other random
number generator that I've used.  Whenever I get bad results, I use
a different seed.

        On thing I *have* noticed about the the random numbers that
pov kicks out is that they *seem* to be more like a stream of pink
"1/f" noise rather than the expected "white" noise: consecutive
values do not differ as much as one would expect (it's as if a "real"
random stream had been run through a mild low pass filter).  I have
read that for more "artistic" uses, this "1/f" noise yeilds more
"pleasing" or "natural" results.
        Or I could just be full of it.  :-)

        I suppose one could write a random number generator in the
pov langauge  (Arc 4 would work nicely), or another way would be
to just use four random streams, one stream picks which of the other
three streams' output to use.  You would be randomly switching
between 3 random streams.  Have not tried this.

Pete

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