POV-Ray : Newsgroups : povray.binaries.images : Four Dimensional Noise - now repeatable : Re: Four Dimensional Noise - now repeatable Server Time
14 Aug 2024 20:26:57 EDT (-0400)
  Re: Four Dimensional Noise - now repeatable  
From: Slime
Date: 8 Oct 2002 19:01:12
Message: <3da363b8$1@news.povray.org>
> I've needed this very often.

Ah, I was hoping you'd reply! You do a lot with animations I noticed, so I
thought this might interest you.

> Suggestion: Make the repeat feature take a 4d vector* rather than a
> float so that the three regular dimensions are also repeatable. With
> that feature, the patch would aslo be very useful for still images.

What you're suggesting here is exactly what I started doing in the first
place. For some reason, I abandoned it and decided that it was better to
only do it in the 4th dimension.

Oh, right, I remember. It seems like a great idea at first, but in practice,
it would only be helpful in very limited situations. See, the thing is, a
repeatable noise pattern in, say, the X direction, is only useful until you
do something more with it. For instance, if you apply turbulence, it no
longer repeats (since the turbulence itself doesn't repeat). If you use it
for the wrinkles or granite pattern, it doesn't repeat anymore, because
you're overlaying it with other versions of itself whose repeat vectors have
different sizes (due to scaling). There are similar situations with other
patterns. In practice, the only place it would repeat would be with a simple
bozo pattern.

This problem doesn't happen in the 4th dimension, since all the manipulation
of the noise function is done in three dimensions.

Besides that, the only use for repeating in dimensions other than the 4th is
for creating tiled images, and there maybe some other obscure uses, but it
just doesn't seem like it'd be helpful enough to implement.

Ideally, one could also apply a noise_generator to a turbulence block, which
would increase it's usefullness. If I ever implement that, perhaps I'll make
repeat a 4D vector.

> * Hmm, you'd have to have some way to specify "no repeat" for each
> dimension. Interpreting 0 as no repeat might suffice.

That's what I'm doing =)

 - Slime
[ http://www.slimeland.com/ ]


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