opencv.read();  // grab images from THE CAMERA

  opencv.convert( GRAY );// convert image to gray scale

  Rectangle[] faces = opencv.detect( 1.2, 2, OpenCV.HAAR_DO_CANNY_PRUNING, 60, 40 ); // detect face

  lights();

  noFill();

  if (faces.length > 0) {

  for( int i=0; i<faces.length; i++ ) {

   float invDist = float(faces[i].height * 10);

   if(invDist >= maxZ)

    {

      maxZ = invDist;

    }

    z = maxZ-invDist;

    float distance = z;

    faceHeight = faces[i].height;  // ensure centrailzed camera

    faceWidth = faces[i].width;

    faceX = faces[i].x;

    faceY = faces[i].y;

    faceZ = distance;

    resetArr(xArr, faceX);/// smoothing

    resetArr(yArr, faceY);

    resetArr(zArr, faceZ);

    avgX = average(xArr);

    avgY = average(yArr);

    avgZ = average(zArr);

    presentX += (avgX - presentX) * 0.5;

    presentY += (avgY - presentY) * 0.5;

    presentZ += (avgZ - presentZ) * 0.5;

    camCenterX = (avgX);

    camY = round(((-height/2+presentY*4)*HALF_PI)+200);

    camCenterY = round(avgY);

    camZ = presentZ;

    camCenterZ = -avgZ; //was previously -z

    camCenterX= camCenterXb;// here are the camera resets to new points from no face detect

    camCenterX=camCenterXb;

    camCenterY= camCenterYb;

    camCenterY=camCenterYb;

    camCenterZ= camCenterZb;

    camCenterZ=camCenterZb;

   }

  }

 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

   // camera circular paths for second if condition

    camX = round(-(-width/2+presentX*4)*HALF_PI);

    camY = round(((-height/2+presentY*4)*HALF_PI)+200);

    //z = faces[i].height*10;

    camZ = presentZ; // was previously distance; also avgZ

  float velocityX, velocityY, velocityZ;

    velocityX = xArr[0] - xArr[7] ; // working out the velocity.

   velocityX = velocityX/15*10;

   velocityY = yArr[0] + yArr[7] ;

   velocityY = velocityY/15;

   velocityZ = zArr[0] - zArr[7] ;

   velocityZ = velocityZ/15*10;

    resetArr(cxArr, camCenterX);/// smoothing

    resetArr(cyArr, camCenterY);

    resetArr(czArr, camCenterZ);

    cavgX = average(cxArr);

    cavgY = average(cyArr);

    cavgZ = average(czArr);

    cpresentX += (cavgX - cpresentX) * 1.1;

    cpresentY += (cavgY - cpresentY) * 1.1;

    cpresentZ += (cavgZ - cpresentZ) * .1;

  ////////////////////////////////////////////////////////////////////////////////

/*THIS IS THE SECTION WHERE IF THE TRACKING GOES BEYOND A CERTAIN POSITION

ON THE X AXIS, THEN FOR THE CAMERA TO ORBIT AROUND THE CENTRE POINT UNTIL THE HEAD IS

TRACKED AGAIN, WHERE BY THE HEAD TRACKING CONTINUES FROM THAT POINT.*//

//////////////////////////////////////////////////////////////////////////

     orbitRadius = (camCenterX + camZ);

   if (faces.length == 0) { // for more than a few frames

   if ( camX > 650){

  camX = orbitRadius * acos(radians(camAlpha))*acos(radians(camBeta));

  camAlpha= camAlpha + velocityX;

         if (camX <= -100) {

       camX = camX +velocityX  ;

       camCenterXb= camCenterX + velocityX;

       camCenterX=camCenterXb;

      }  

 }

    perspective();

  camera(camX, camY, camZ, // eyeX, eyeY, eyeZ

  camCenterX, camCenterY, camCenterZ, // centerX, centerY, centerZ

  0.0, 1.0, 0.0); // upX, upY, upZ

  directionalLight(255,255,255,-1,0.5,0);