Post a Comment On: C0DE517E

I had to write in a rush some code to generate low-discrepancy samples in a shape (i.e. hemisphere). For those kind of quick hacks I find processing to be great, mostly because of its visual nature.
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The code is really stupid and it requires some manual interaction. With the left mouse button you dump the sample info, with the middle you shrink the sample minimum distance spheres, with the right you add a random shake to the whole thing (yes, it's laughable...).
Anyways. Here it is.



//  Generates a packing of points inside a 2d shape //  press right/middle mouse buttons a few times until convergence... class pnt {   float x; float y; }; pnt points[] = new pnt[16]; float mindist = 60; void setup() {   size(512, 512, P3D);   fill(204);        for(int i=0; i< points.length; i++)   {     points[i]=new pnt();     points[i].x = random(200)-100;     points[i].y = random(200)-100;   } } void mousePressed()  {   if(mouseButton == LEFT)   {     for(int i=0; i< points.length; i++)     {       float len = sqrt(points[i].x*points[i].x + points[i].y*points[i].y);       println(points[i].x/100.0 + ", " + points[i].y/100.0 + ", " + len/100.0 + ",");     }   }   else if(mouseButton == CENTER)   {     mindist -= 5; // manual control...   }   else // RIGHT mouse button   {     // A LITTLE BIT OF NOISE     for(int i=0; i< points.length; i++)     {       points[i].x += random(mindist/10)-(mindist/20);       points[i].y += random(mindist/10)-(mindist/20);     }   } } void draw() {   lights();   background(0);      // Change height of the camera with mouseY   camera(30.0, mouseY, 400.0, // eyeX, eyeY, eyeZ          0.0, 0.0, 0.0, // centerX, centerY, centerZ          0.0, 1.0, 0.0); // upX, upY, upZ      noStroke();   float totaldist = 0;   // DISTANCE CONSTRAINT   for(int i=0; i< points.length; i++)   {            for(int k=0; k<50; k++)     {       int j = (int)random(points.length);       if(i!=j)       {         pnt tmp = new pnt();                  tmp.x = points[j].x - points[i].x;         tmp.y = points[j].y - points[i].y;                  float len = sqrt(tmp.x*tmp.x + tmp.y*tmp.y);                  if(len< mindist)         {           tmp.x = (tmp.x/len)*mindist;           tmp.y = (tmp.y/len)*mindist;           points[i].x = points[j].x - tmp.x;           points[i].y = points[j].y - tmp.y;                      totaldist += len;         }       }     }   }      // DISTANCE FROM ZERO CONSTRAINT   for(int i=0; i< points.length; i++)   {              float len = sqrt(points[i].x*points[i].x + points[i].y*points[i].y);              if(len< mindist)       {                 points[i].x /= len/(mindist);         points[i].y /= len/(mindist);       }   }      // SHAPE CONSTRAINT   for(int i=0; i< points.length; i++)   {         float len = sqrt(points[i].x*points[i].x + points[i].y*points[i].y);          if(len>100)     {       points[i].x/=len/100.0;       points[i].y/=len/100.0;     }   }      // display distance violation   totaldist = sqrt(totaldist);   fill(15,15,15,255);   box(totaldist);        for(int i=0; i< points.length; i++)   {       pushMatrix();       translate(points[i].x,points[i].y,0);       if(mindist>0)       {         fill(255,255,255,64);         sphere(mindist);       }       fill(255,0,0,255);       sphere(5);                  popMatrix();   } }