Well, it really depends on how the mountain should look like. Is it two-dimensional (e.g. side-view) or three-dimensional? Does it have a high resolution or is it rather coarse?

ok, im interested in creating a 3d mountain , that looks realistic with details. Any idea?

The classic route is taking a flat mesh (say 100 x 100) and moving each vertex in its y-position according to the brightness of an image ( heightmap). The image can also be created inside processing using the noise() function.

Last question, is there any mesh object or function in processing? Or do i need to do my own mesh with lines?

thanks

use beginShape() endshape() for it.

take a look at this example code :

1. 
   
   import peasy.*;
   
   PeasyCam cam;
   
   float noiseScale= .12;
   
   
   int meshSize = 10;
   int resX = 50;
   int resY = 50;
   float[][] val = new float[resX][resY];
   
   void setup() {
     size(900, 600, P3D);
     smooth();
     background(255);
   
   
     cam = new PeasyCam(this, 0, 0, 0, 600);
   }
   
   void draw() {
   
     translate(-resX/2*meshSize, -resY/2*meshSize);
     noiseScale= mouseX*.0002;
   
     float xoff = 0.0;
     for (int x =0; x<resX; x++) {
       xoff +=noiseScale;
       float yoff = 0.0;
       for (int y =0; y<resY; y++) {
   
         yoff +=noiseScale;
   
         val[x][y] = noise(xoff, yoff)*255;
       }
     }
   
     background(0);
   
   
   
     for (int x =0; x<resX-1; x++) {
       for (int y =0; y<resY-1; y++) {
         beginShape();
         colorMode(HSB, 255);
         fill( val[x][y], 255, 255);
   
         vertex(x*meshSize, y*meshSize, val[x][y] );
         vertex((x+1)*meshSize, y*meshSize, val[x+1][y] );
         vertex((x+1)*meshSize, (y+1)*meshSize, val[x+1][y+1] );
         vertex(x*meshSize, (y+1)*meshSize, val[x][y+1] );
   
   
         endShape(CLOSE);
       }
     }
   }
   
   
   
   
   

If you want to display large maps, take a look to space partition. The easiest one must be the Quad-Tree and is pretty efficient.

thanks for the code, i been playing with it and it work slow on my computer, is that normal behaivor?
Is there is another way of doing beginShape endShape in more efficient way?
 maybe in the gpu?

Your code looks more like a terrain to me its a surface, not really a mountain, i need that it would have  the shape of a mountain.
I was thinking maybe adding some kind of constrains to make it look more like a mountain, In the middle of the mesh adding more values so that part is always the highest part,  and the borders make it always flat.
 how can i approach something like this using beginshape? any idea?

thanks

S.

sure its not a mountain, its just perlin noise, but as allesblinkt said. you can use a heightmap instead or any other way to pass the values...

I would probably handle the heightmap / noise values as an image in Processing. You can do a lot with this stuff.