Harmonize: a shared environment for extended immersive entertainment.

Virtual reality (VR) and augmented reality (AR) applications are very diffuse nowadays. Moreover, recent technology innovations led to the diffusion of commercial head-mounted displays for immersive VR: users can enjoy entertainment activities that fill their visual fields, experiencing the sensation of physical presence in these virtual immersive environments. Even if AR and VR are mostly used separately, they can be effectively combined to provide a multi-user shared environment (SE), where two or more users perform some specific tasks in a cooperative or competitive way, providing a wider set of interactions and use cases compared to immersive VR alone. However, due to the differences between the two technologies, it is difficult to develop SEs offering a similar experience for both AR and VR users. This paper presents Harmonize, a novel framework to deploy applications based on SEs with a comparable experience for both AR and VR users. Moreover, the framework is hardware-independent, and it has been designed to be as much extendable to novel hardware as possible. An immersive game has been designed to test and to evaluate the validity of the proposed framework. The assessment of the system through the System Usability Scale questionnaire and the Game Experience Questionnaire shows a positive evaluation.