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Patricio Gonzalez Vivo 2015-03-22 13:31:59 -04:00
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@ -30,11 +30,11 @@ y *= 0.1;
Think on the surface of the ocean. This massive amount of water is propagating waves across it surface. Waves of diferent amplitud and frequencies.
## 1D Fractal Brownian Motion
## Fractal Brownian Motion
By adding different octaves of the same noise function we can gain some extra granularity from the noise. Take a look to the following example and progresively change the for loop to do 2,3,4,5,6,7 and 8 iterations. See how incrisinly fragmented this wave function becomes.
By adding different octaves of increasing frequencies and decreasing amplitudes of noise we can gain some extra granularity. This technique is call Fractal Brownian Motion and is very well documented in [this](http://www.iquilezles.org/www/articles/warp/warp.htm) [two](http://www.iquilezles.org/www/articles/morenoise/morenoise.htm) articles of Iñigo Quilez.
"simple sum of perlin noise functions with increasing frequencies and decreasing amplitudes" Iq at http://www.iquilezles.org/www/articles/warp/warp.htm
Take a look to the following example and progresively change the for loop to do 2,3,4,5,6,7 and 8 iterations. See how incrisinly fragmented this wave function becomes.
<div class="simpleFunction" data="
float a = 0.5;
@ -44,9 +44,7 @@ for( int i = 0; i < 1; ++i) {
a *= 0.5;
}"></div>
## 2D Fractal Brownian Motion
This fine level of fragmentation is what we are interested. ...
If we apply this to 2D will look like the following code:
<div class="codeAndCanvas" data="2d-fbm.frag"></div>
@ -56,8 +54,6 @@ http://www.iquilezles.org/www/articles/warp/warp.htm
http://www.iquilezles.org/www/articles/morenoise/morenoise.htm
http://www.iquilezles.org/www/articles/dynclouds/dynclouds.htm
<div class="codeAndCanvas" data="clouds.frag"></div>