HOCTOPUS: An Open-Source Cross-Reality tool to Augment Live-Streaming Remote Classes

Extended Reality (XR) has gained significant attention, offering novel pathways for learning based on the sharing of 3D content. Nevertheless, additional efforts should be spent to understand the advantages set forth by Cross-Reality (CR) scenarios, for example including Augmented Reality (AR) and Mixed Reality (MR) experiences in the context of remote live-streaming classes. In this process, a necessary step entails designing, implementing, and making educational tools available in an open-source format. To this aim, we present HOCTOPUS, a CR system designed to support live remote teaching. HOCTOPUS provides a cross-reality educational experience: an MR application for teachers and an AR mobile app for students. HOCTOPUS lets teachers visualize, manipulate, and share 3D objects in a live-streaming fashion, supporting bidirectional communication and interactions with all students. The MR component is developed for the Hololens 2, offering flexible manipulation capabilities, while the AR component runs on Android mobile devices, providing affordable interactive visualization and manipulation. The proposed tool may be used as a building block to enhance the learning process and is made available to the educational community for its use, assessment, and extension.