The empty museum. Multi-user interaction in an immersive and physically walkable VR space

Until quite recently, virtual reality systems consisted of fixed devices which enabled the user to feel immersed in a spot of the virtual space by means of the adequate hardware. The recent emergence of wireless systems for motion capture, together with the increase in graphic power of laptops, and the generalisation of wireless networks has allowed the appearance of the first systems in which at last the user is able to walk physically within a given space framed in the real one, and containing the objects and elements of the virtual space. Some examples of this hybrid space have already been accomplished worldwide. However, beyond the technical problems with the development of these systems, we must bear in mind the types of contents to be shown, making the most of the possibilities offered by the fact that the user him/herself is the pointer in this kind of virtual reality, while the space itself is the interface. The authors have recently developed a system similar to the ones described. This is a totally immersive, walkable and wireless system called the Empty Museum. The paper outlines its enlargement with the purpose of making it simultaneously usable by several persons. Besides, an example of content is provided which has been specifically designed in order to be experienced in multi-user mode with this equipment: the Virtual Art Gallery.