Component evaluation priority is first X, then Y, then Z.
public int CompareTo( Point3d other )
Public Function CompareTo ( other As Point3d ) As Integer
0: if this is identical to other
-1: if this.X < other.X
-1: if this.X == other.X and this.Y < other.Y
-1: if this.X == other.X and this.Y == other.Y and this.Z < other.Z