Octant of space, axes and planes included. 1 to 4 are the quadrants 1 to 4 with z >= 0; 5 to 8 are the same quadrants with z <= 0 (so octant 5 is below octant 1).
z >= 0
z <= 0
Octant of space, axes and planes included. 1 to 4 are the quadrants 1 to 4 with
z >= 0; 5 to 8 are the same quadrants withz <= 0(so octant 5 is below octant 1).