This work’s contribution lies in providing the computational routine that presents the reflective boundary conditions, coupled with the computational module dedicated to the Smoothed Particle Hydrodynamics (SPH) method. The implementation began in two-dimensional (2D) domains, and development continued for a few years so that the three-dimensional (3D) implementation was carried out consistently, allowing the validation of some cases in this latter domain. The number of particles, parameters, and initial conditions used in simulations is essential to guarantee the convergence of the results. If the parameters in the routines are changed, the simulation results can also be substantially altered. In this manner, if the reader wants to explore the routines with different combinations of particles and parameters, it will be necessary to do studies of the convergence of the results (which is normal in the SPH method simulations).