+-----+
      |     |
      |  4  |
      |     |
+-----+-----+-----+-----+
|     |     |     |     |
|  1  |  0  |  3  |  2  |
|     |     |     |     |
+-----+-----+-----+-----+
      |     |
      |  5  |
      |     |
      +-----+

Observer stands in the middle of the cube with 0 in front, 1 to the left, 2
behind, 3 to the right, 4 above and 5 below.