int points;
float sigma,r,b, bound,step,roff;
float[][] uni;
color[] colors;

float friction=0.99F;

float centerx,centery,mx,my,dx,dy,maxwrot,maxhrot,rotx,roty;
void mouseDragged()
{
  dx=(mouseX-float(pmouseX))*maxwrot;
  dy=(mouseY-float(pmouseY))*maxhrot;
}

void updateSpace()
{
  translate(centerx,centery);
  if(!mousePressed)
  {
    rotx+=mx;
    roty+=my;
    mx*=friction;
    my*=friction;
  }
  else
  {
    rotx+=dx;
    roty+=dy;
    mx=dx;
    my=dy;
    dx=dy=0;
  }
  rotateX(-roty);
  rotateY(rotx-roff);
}

void setup()
{
  size(400,400, P3D);
    
  sigma=10; //10
  r=28; //28
  b=(8/3); //8/3
  
  points=2000;
  bound=50;
  step=0.003;
  
  uni=new float[points][3];
  colors=new color[points];
  
  colorMode(HSB);
  
  float maxd=sqrt(3*bound*bound);
  for(int i=0;i<points;i++)
  {
    float[] n=new float[3];
    for(int j=0;j<3;j++)
    {
      n[j]=random(-bound,bound);
    }
    uni[i]=n;
    colors[i]=color(sqrt(n[0]*n[0]+n[1]*n[1]+n[2]*n[2])*255/maxd,255,200);
  }
 
  roff=HALF_PI/1.5;
  centerx=width/2;      
  centery=height/2;     
  maxwrot=TWO_PI/width; 
  maxhrot=TWO_PI/height;
  
  noFill();
}

void loop()
{
  background(255);
  updateSpace();
  
  stroke(0);
  box(200);
  translate(0,0,-130);
  scale(5);
  
  float x,y,z;
  for(int i=0;i<points;i++)
  {
    x=uni[i][0];
    y=uni[i][1];
    z=uni[i][2];
    
      uni[i][0]+=(sigma*(y-x))*step;
      uni[i][1]+=((-x*z)+(r*x)-y)*step;
      uni[i][2]+=((x*y)-(b*z))*step;
      
    stroke(colors[i]);
    line(x,y,z,uni[i][0],uni[i][1],uni[i][2]);
  }
}