Processing 1.0 - Processing Discourse - using perlin noise to create a rough boundary

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Index › Programming Questions & Help › Syntax Questions › using perlin noise to create a rough boundary

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using perlin noise to create a rough boundary (Read 552 times)

oompa_l

using perlin noise to create a rough boundary
Feb 2^nd, 2009, 8:09am

I have never used perlin before and am trying to get my head around a use I have for it...well I think it could do what I want but I am open to suggestions. I have ellipses which I would like to use a base geometry from which to slightly randomize or create a 'natural' looking edge. I imagine that there might be a way to draw a circle using a number of bezier or other curve type points and I would use some noise like function to slightly shift each of the points off their neutral position...

anyone have any ideas ho I might do this?
thanks

eskimoblood

Re: using perlin noise to create a rough boundary
Reply #1 - Feb 2^nd, 2009, 9:53am

You can use curveVetex. Simple create a list of minimal 5 points on circle and add perlin noise to the radius in every step:

Code:


beginShape();
int rad  =100;
float steps = 10.0;
loat strangeFactor = 10.0;
for(int i=0; i<steps ; i++){
 float x=cos(TWO_PI/steps*i)*(rad+perlinNoise(i)*strangeFactor);
 float y=sin(TWO_PI/steps*i)*(rad+perlinNoise(i)*strangeFactor);
 curveVeretx();
}
endShape();

Andreas Köberle {eskimoblood}

oompa_l

Re: using perlin noise to create a rough boundary
Reply #2 - Feb 2^nd, 2009, 11:40pm

thanks! do I need a toxi library in order for the perlinNoise function to work?

this is the way I implemented it -i couldn't find a perlinNoise function

float rad = diameter/2;
float steps = 10.0;
float strangeFactor = 5.0;

beginShape();
for(int i=0; i<steps ; i++){
float x=this.p.position().x()+cos(TWO_PI/steps*i)*(rad+noise(i)*strangeFactor);
float y=this.p.position().y()+sin(TWO_PI/steps*i)*(rad+noise(i)*strangeFactor);
curveVertex(x, y);
}
endShape();

each roughened circle ends up looking exactly the same. what's the best way to get them to look different - should I be using the random function instead?

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: using perlin noise to create a rough boundary Reply #3 - Feb 3^rd, 2009, 12:59am I think eskimoblood meant noise() instead. You need to use noiseSeed() to vary the results a bit, or make noise() depend on time, along or along i, etc.

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