Parametric sweep and geometry change

a,b,theta_a and theta_b are global geometry parameters. theta_a = 2/a, and theta_b = 2/b. a,b,theta_a, and theta_b are all used in geometry creation.

I am running a parametric sweep for parameters a and b. When I do this the geometry that is created is not correct. The geometry created for each pair of a and b reflect the change in a and b but does not calculate a new theta_a and a new theta_b. Hence my geometry looks weird.

Any help will be greatly appreciated.