// RANDOM POINT ON A CUBE. Return a Vector3
 public Vector3 PointOnACube(Normalization n, float t)
 {
     return(RandomCube.Surface(ref _rand, n, t));
 }
 // RANDOM POINT ON A CUBE. Return a Vector3
 public Vector3 PointOnACube()
 {
     return(RandomCube.Surface(ref _rand));
 }