RomainKurtz

//To compute the center of two points (vector3: x,y,z) in 3D space
function centerAB (A,B){
  var x = ((A.x+B.x)/2);
  var y = ((A.y+B.y)/2);
  var z = ((A.z+B.z)/2);
  return new THREE.Vector3(x,y,z);
}

RomainKurtz

//For compute the distance between 2 points (Vector3 : x,y,z) in 3D space
function distanceAB(v1, v2) {
  var dx = v1.x - v2.x;
  var dy = v1.y - v2.y;
  var dz = v1.z - v2.z;
  return Math.sqrt(dx * dx + dy * dy + dz * dz);
}