Hi there.

I'm trying to create a class that wanders around the screen in a pseudo natural path. I'm taken daniel shiffman's walker class, and used perlin noise instead of random() to create a more natural effect. It all works as expected, but if I create 2 instances of the class they both move together.

Does noise() always produce the same numbers, or is there a way for it to create different numbers for each instance

Here's a simplification of the code:

Using random() Works as expected, each instance moves on it's own random path
Code:

  void walk() {
    int vx = int(random(3))-1;
    int vy = int(random(3))-1;
    x += vx;
    y += vy;
  } 

Using noise() All instances move together
Code:

  int jumpSize = 22;
  float xoff = 0.0;
  float xincrement = 0.1; 
  float yoff = 0.0;
  float yincrement = 0.11;   

  void walk() {
    float vx = (noise(xoff)*jumpSize) - jumpSize/2;
    float vy = (noise(yoff)*jumpSize) - jumpSize/2;
    x += vx;
    y += vy;
    xoff += xincrement;
    yoff += yincrement;
  } 

I've looked through the documentation and the Processing book (I just got for christmas :) but can't find anything that would explain this behaviour. I suspect I need to define, or initiate noise, to ensure it's instance level, rather than class level.

Any pointers in the right direction?

Thanks

Thanks very much.

I just set the offset to a random number in the constructor and it's now working quite well.

Thanks for your help!