POV-Ray : Newsgroups : povray.general : rand question : Re: rand question Server Time
5 Aug 2024 04:17:40 EDT (-0400)
  Re: rand question  
From: Vadim Sytnikov
Date: 12 Feb 2003 12:05:44
Message: <3e4a7ee8$1@news.povray.org>
"Christopher James Huff" <cja### [at] earthlinknet> wrote:
>
> >   (On implication of this is that if you have two streams generated
> > with different seed() values, they will both eventually start to give
> > the same numbers as the other.)
>
> Not correct. They will both repeat, and repeat the same sequence, but if
> they are initialized with different seeds, they will always have
> different numbers at any moment. Assuming you pull random numbers from
> each at an equal rate, anyway.

I think the notion of "any moment" is not particularly applicable here...
Imagine a scene similar to one generated with Chris Colefax's City
Generator. The implication that Warp (probably; me -- certainly) meant is
that is if you, say, use different streams *and* different seeds for each
block, you may still end up with very similar blocks since the sub-sequences
your RNGs generate may still overlap.

To be even more specific: think about blocks with scattered trees. If your
streams' sub-sequences overlap, you may end up with many *equally* (not even
"similarly") shaped and located trees in different blocks. Hope you got the
idea...


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