Angular Discretization for 2d DO Model

RAO

hi,

In Section 12.3.14 "Defining the Angular Discretization for the DO Model" of UG, it tells that "Theta Divisions and Phi Divisions will define the number of control angles used to discretize each octant of the angular space". and "For a 2D model, a total of 4NN directions will be solved".

I can understand the polar angle Theta and azimuthal Phi in 3D problem. But I think only Theta or Phi is enough in 2D problem. So cound you kindly tell me how the angular space is divided in 2D problem, i.e. what is the meaning of the polar angle Theta and azimuthal Phi in 2D problem.

Additionally, Cound you tell me if we can control this angular discretization instead of constants in all directions.

thanks a lot!