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Index › Programming Questions & Help › Syntax Questions › limit the movement of noise()
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limit the movement of noise() ? (Read 176 times)
Johnney
limit the movement of noise() ?
Feb 13th, 2009, 4:55pm  
Hi everyone,

I'm trying to limit the movement of noise() so my object cannot exceed some X and Y value.
I want it to move randomly and that's why i use noise().

Code:

float xoff = 0.0, yoff = 0.0, noiseScale1=0.4, noiseScale2=0.4;
float n1, n2;

void setup() {
  size(200, 200);
  background(0);
  smooth();
  fill(255);
  
  noiseDetail(3);
}

void draw() {
  background(0);
  xoff += 0.01;
  yoff = ((millis()/1000.0));
  n1 = noise(xoff*noiseScale1) * height;
  n2 = noise(yoff*noiseScale2) * height;
  
  println("original N1 "+n1);
  println("original N2 "+n2);
  println();
  
  if (n1 <= -50) {n1 += 5;}
  if (n1 >= 50) {n1 -= 5;}
  if (n2 <= -50) {n2 += 5;}
  if (n2 >= 50) {n2 -= 5;}
  
  println("new N1 "+n1);
  println("new N2 "+n2);
  println();
  
  ellipse(n1, n2, 10, 10);
}


The problem is n1 and n2 doesn't redefine their value based on the operation from "if" operator.
Why does the original n1 and n2 doesn't change?

Thanks and have a nice day!
Jonathan
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PhiLho 
Re: limit the movement of noise() ?
Reply #1 - Feb 13th, 2009, 5:19pm  
Your values cannot be negative.
noise() returns a value between 0.0 and 1.0.
If you want a resulting number between a and b, either use map() or the simple formula: n = a + (b - a) * n;
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Johnney
Re: limit the movement of noise() ?
Reply #2 - Feb 13th, 2009, 6:21pm  
thx Philho for the fast answer!!
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