General Surveys of the Cubic
    b-plane holding a constant, z=+sqrt(-a/3)
    a-plane holding b constant, z=+sqrt(-a/3)
    polar survey
 
 
b-plane holding a constant, z=+sqrt(-a/3)

Survey of the set cutting through the b-plane by holding a constant and iterating from z=sqrt(-a/3).

a-plane holding b constant, z=+sqrt(-a/3)

Survey of the set cutting through the a-plane by holding b constant and iterating from z=sqrt(-a/3).

polar survey

Survey of the set in the b-plane, holding a constant but treating a in polar coordinates.  The survey holds the radius of a constant and changes the angle.