Selecting this command initiates a dialog that contains three, mutually exclusive options selectable via associated radio buttons.  These options affect the way that the program’s random number routine operates.

Uniform Noise produces random numbers that are uniformly distributed over the selected.  This type of noise tends to produce the most exaggerated landscapes, and generally requires a larger width to height ratio (see Modify Parameters) to somewhat mute the effect.

Gaussian Noise produces random numbers that are distributed in a standard Gaussian bell curve.  This is the type of noise called for in most texts on fractals.  Due to the reduced chance of extreme random numbers, Gaussian noise results in subtler shapes that might be appropriate for smaller width to height ratios (see Modify Parameters).

Sinusoidal Noise produces random numbers that are distributed in a sine curve.  The effects are similar to but different from those of Gaussian noise.