

Perlin Noise - copernicus
http://freespace.virgin.net/hugo.elias/models/m_perlin.htm

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rohitarondekar
This is just a simplistic description of Perlin Noise. However while
implementing the algorithm this is not the way to go. Because it's very very
slow -- the author has simply taken non-coherent noise and smoothened it and
this is computationally very expensive.

And also Ken Perlin has made an improved version to his original with some
speedups and a reference implementation in Java can be found here:
<http://mrl.nyu.edu/~perlin/noise/>

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J3L2404
Where are the permutation numbers derived from?

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rohitarondekar
They are generated randomly. Ken Perlin has described it in his book
Texturing, Modeling A Procedural Approach. If I remember correctly the numbers
have to be such that every direction should have an equal chance. Even
distribution I think.

~~~
J3L2404
I was thinking it would be more like the fast inverse square from Quake. If
it's random, using the same code could be a problem, no?

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ivan_i
I wrote a Python extension based on the original Ken Perlin's algorithm. Just
found it on my hard drive and uploaded it to github:
<http://github.com/ii/perlin>

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rohitarondekar
I've implemented 2D perlin noise for my final year project, but I think it has
mistakes in it. Never got the time to verify. If anybody wants to take a look
it's here:
[http://trac.assembla.com/terrainium/browser/TerrainiumLatest...](http://trac.assembla.com/terrainium/browser/TerrainiumLatest/Terrainium/src/terrainium/AlgorithmPerlin.java)

perlinNoise() is the function to look at. I implemented it based on
[http://web.archive.org/web/20070706003038/http://www.cs.cmu....](http://web.archive.org/web/20070706003038/http://www.cs.cmu.edu/~mzucker/code/perlin-
noise-math-faq.html) but the images are missing in the web archive :(

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z8000
Wow, 2 Ken Perlin related posts in an hour! I met Ken Perlin once very briefly
and randomly and was a bit in shock when I realized who I was talking to. He
was in shock that I was in shock. Nice (and very smart) guy.

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ivankirigin
Ken Perlin is one of the best computer science professors at NYU. Take a class
of his if you get the chance.

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tfinniga
If you're interested in noise functions, you might want to check out Pixar's
wavelet noise - <http://graphics.pixar.com/library/#WaveletNoise>

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perplexes
A never-released (3d space mmorpg wing-commander-esque) game my friends worked
on for a while used this for texturing their worlds:
<http://www.cocommand.com/>

