LightNet: a networking library to perform multi-participant experiments in Virtual Reality

Multi-participant experiments in virtual reality (VR) could provide a new way to investigate real-time interactions in a controlled and ecologically valid environment. However, to create the impression of a shared world between participants, all non-static elements of the environment need to be networked. Currently available networking solutions contain complex automated functionalities and were developed for the demands of multiplayer video games. However, the required level of expertise to tweak such automated functionality is difficult to acquire during the short time frame of an experimental project's implementation phase. As the focus of multi-participant experiments lies on the control of experimental variables and data quality, we propose a new light-weight networking solution called LightNet, specifically designed for the needs of implementations of multi-participant experiments.LightNet is an open-source networking library. It provides a transparent software architecture, multiple customization options, and precise networking of variables to ensure control over experimental variables and data quality. In this article, we present a "how-to" section in which we explain the necessary steps to include networking functionalities using LightNet. We conclude this section with a list of additional recommendations for any LightNet implementation. Furthermore, we describe the networking logic and properties of a more complex example experiment, incorporating shared gaze.Overall, we believe that the provided networking solution facilitates the implementation of multi-participant experiments to enable a comprehensible access to investigating social interactions in VR, even without expert-level expertise in the field of networking.