Many people have used random number generators in their programs to create unpredictability, make the motion and behavior of objects appear more natural, or generate textures. Random number generators certainly have their uses, but at times their output can be too harsh to appear natural. This article will present a function which has a very wide range of uses, more than I can think of, but basically anywhere where you need something to look natural in origin. What's more it's output can easily be tailored to suit your needs.

If you look at many things in nature, you will notice that they are fractal. They have various levels of detail. A common example is the outline of a mountain range. It contains large variations in height (the mountains), medium variations (hills), small variations (boulders), tiny variations (stones) you could go on. Look at almost anything: the distribution of patchy grass on a field, waves in the sea, the movements of an ant, the movement of branches of a tree, patterns in marble, winds. All these phenomena exhibit the same pattern of large and small variations. The Perlin Noise function recreates this by simply adding up noisy functions at a range of different scales.

Perlin Noise, named after its inventor Ken Perlin, is a widely used texturing primitive in two- and three- dimensional image creation. The Perlin Noise function generates a smoothly interpolated space of pseudo-random values which can be used as the basis for the procedural generation of realistic natural textures, such as marble, clouds, grass and many others.

 

 

 

PERLIN NOISE PLUGIN

for 3DSMax

 

Perlin Noise plugin for 3DSMax (developed by Yaroslav Barsoukov and Dimitriy Maslennikov for Consortium “Geometrical Education in New Information Technologies”) adds a new type of 3D texture to 3DSMax Material Browser. The plugin allows user to control the main parameter of generated noise - the number of octaves, and also its alpha and beta parameters.

 

Octaves
            In nature a fractal relationship is often seen, so that as you look more closely into a pattern it often includes smaller versions of itself. The Octaves parameter simulates this effect by adding scaled down versions of the noise function to itself with progressively smaller amplitude. For example, setting Octaves to two means you get the standard noise function plus the same function at half scale with half of the amplitude. Upping the number of Octaves means that the pattern is more complex and more natural looking but also takes longer to generate.

 

Use Absolute Value (alpha)
            Normally the Perlin Noise function outputs a value between -1 and 1. By taking the absolute value of the output you can modify the look of the noise that's generated, particularly when adding Octaves together.

 

Scale
            This is used to control how the coordinates of the noise function space are mapped onto the output. You use this zoom in and out of the space.

 

Perlin Noise on 2 octaves

 

Perlin Noise on 4 octaves