repeating 3d simplex noise? about noise

[caseman]

Perlin noise is easier to repeat because it is rectangular in nature. Since simplex noise is triangular it requires a more complex solution using higher dimensional noise.

However you may notice that 2D simplex noise supports a "base" argument as well as x and y repeat intervals. This value offsets the periodic higher dimension used to tile the noise. This effectively "randomizes" the noise output without needing even higher dimensions of noise.

I used that as a seed in my map generator to good effect: https://gist.github.com/caseman/8554090