The combination of arrays with dielectric lenses is an attractive solution to improve the antenna performance for millimeter wave applications. The design and optimization of these lenses present significant challenges. This is primarily due to the computational intensity of simulating them with full-wave software packages, especially since an extra simulation is required to determine the nonlinear phase distribution of the array. A potential solution to accelerate the design process is the implementation of a ray tracing (RT) method. To address the limitations of our earlier in-house 2D RT model, we are currently upgrading it to a 3D version. In this context, we outline the steps involved in geometry creation and geometrical optics within the model. The geometrical optics include both reverse RT (for phase distribution retrieval) and direct RT (for radiation pattern calculation). Our results show a good agreement with the theory.