In this paper, we present MVC-3D design pattern to develop virtual and augmented (or mixed) reality interfaces that use new types of sensors, modalities and implement specific algorithms and simulation models. The proposed pattern represents the extension of classic MVC pattern by enriching the View component (interactive View) and adding a specific component (Library). The results obtained on the development of augmented reality interfaces showed that the complexity of M, iV and C components is reduced. The complexity increases only on the Library component (L). This helps the programmers to well structure their models even if the interface complexity increases. The proposed design pattern is also used in a design process called MVC-3D in the loop that enables a seamless evolution from initial prototype to the final system.