Rectangle intersections 3D

Processing Coding Questions
1

Hi there,

I am trying to place some rotated rectangles in 3D but the rendering would be much better if the intersection lines between them would be visible. Can anyone help me do that?

float x,y,z,a,b ;
int num = 300 ; 
int side = 500;
int imax = 0; 
float y0 = 2./3;
int radius;

int previousDisplayTime;  // Keep track of the last time a frame of the animation was displayed
int deltaTime; 

boolean sense = true;
boolean pause = false;

void setup() {
  size(1000,1000,P3D);
  lights();
  //ortho();
  y0 = height;///2+side/2;
  println(y0);
  x = width/2;
  y = y0;
  z = 0;
  a = 0;
  b = 0;
  
  directionalLight(255, 255, 255, 0, -1, -1);
  
  deltaTime = 100;
  previousDisplayTime = 0;  
  
  //float fov = PI/2;
  //float cameraZ = (4000) / tan(fov/2.0);
  //perspective(fov, float(width)/float(height), 
  //          cameraZ/10.0, cameraZ*10.0);
}

void draw() {
  radius = side + mouseX;
  lights();
  //stroke(220);
  stroke(255*1/4);
  //noStroke();
  background(220, 220, 220);  
  //background(255);
  //fill(255, 0, 0, 10);
  camera(//width, 0, width/3, // eyeX, eyeY, eyeZ
         width/2-10*width/4, height/2-10*width/4, radius-10*width/4,
         0, 0, 0,
         //3*width/4, width/4, width/8, // centerX, centerY, centerZ
         0.0, 1.0, 0.0);


  perspective(PI/3.0, float(width)/float(height), mouseX, 10*radius-100*width/4);//1, 25*radius);
  
  
  if ((millis() > previousDisplayTime + deltaTime) & sense & !pause) {
    imax++;
    if (imax > num) { 
      sense = false;
    }
    previousDisplayTime = millis();
  }

  if ((millis() > previousDisplayTime + deltaTime) & !sense & !pause) {
    imax--;
    if (imax < 0) { 
      sense = true;
    }
    previousDisplayTime = millis();
  }


  for (int i=0; i < imax; i++) {
      x = radius * cos(i*2*PI/num);
      y = radius * sin(i*2*PI/num); 
      drawSheet(i);
      //y-=side/(num-1); // The rectangle moves forward as z increments.
      a+=0.02*mouseX/width*20;
      b+=0.02*mouseY/width*20;
  }
  
  a = 0;
  b = 0;
  y = y0;
  x=width/2;

}

void mousePressed() {
 pause = !pause; 
}

void drawSheet(int i) {
  pushMatrix();
  translate(x,y,0);
  rectMode(CENTER);
  fill(255);
  //rotateX(-PI/6);
  //rotateY(PI/3);
  rotateX(PI/2);
  rotateY(2*PI/num*i);
  rotateZ(a);
  rotateY(b);
  rect(0,0,side,side);
  popMatrix();
}