— HRI is a multi-disciplinary research field and integrating the range of expertise into a single project can be challenging. Enabling experts on human behavior to design fluent animations and behaviors for advanced robots is problematic, since the tools available for such robots are often in their prototype stage. We have built The Robot Engine (TRE) based on the Unity 3D Game Engine to control robots with Unity 3D. Unity 3D allows non-programmers to use a set of powerful animation and interaction design tools to visually program and animate robots. We review several animation techniques that are common in computer games and that could make the movements of robots more natural and convincing. We demonstrate the use of TRE with two different Arduino based robot platforms and believe that it can easily be extended for use with other robots. We further believe that this unconventional integration of technologies has the potential to fully bring the expertise of interaction designers ...