Re: [pygame] Perlin Noise Function

[Casey Duncan <casey@xxxxxxxxxxx>]

On Jul 30, 2008, at 11:08 AM, Knapp wrote:
> [..]
>
> One of the links I posted talked about the 3d+ Speed problems and  
> how to fix them. Have you see that yet?

I had seen that before. The gradient optimization mentioned is really  
only applicable to classic Perlin noise. The Perlin Improved noise  
algorithm optimizes the gradients in a different way. The gradients  
themselves in "improved noise" are no longer random, though they are  
selected in a pseudo-random fashion, by hashing the incoming  
coordinates. Basically. the moral equivalent of the optimization is  
already present in "improved" noise.

The scaling problem for higher dimensions is solved nicely by simplex  
noise, which grows linearly in cost as you add dimensions, rather than  
geometrically. However, simplex noise looks considerably different,  
and so even a higher cost 4D Perlin noise function is probably still  
desirable for applications not sensitive to that cost. 4D noise is  
highly useful for real-time applications where you desire to animate a  
3D texture, and there, cost is typically important.

-Casey