In virtual reality (VR), portals serve as a common metaphor for relocation, allowing users to navigate large virtual environments. However, portal design is often ad hoc, leaving developers without clear principles for their intentional design and placement to support specific experiential or performance goals. We present a taxonomy for VR portals, deconstructing them into three main dimensions: World-related, Portal-related, and User-related. Based on the suggested taxonomy, we implemented eight unique portals varying across three categories: World Integration (Integrated vs. Non-Integrated), Nature Definition (Obvious vs. Subtle/Hidden), and Destination Visibility (Preview vs. Occluded). We assess the impact of these factors, focusing on spatial memory, presence, and experience in a user study with 32 participants. Our results show that World-Integrated portals improve spatial memory and realism, while the exposure of portal’s unusual Nature mainly affects perceived realism. Visibility of the portal’s Destination positively affected user comfort, acceptance, and presence. We discuss the insights for the intentional design of a portal-based relocation techniques that support comfortable and intuitive navigation. Such techniques are particularly suitable for small physical spaces, where portals enable space-efficient, self-overlapping virtual architectures.

Teleportation dominates Virtual Reality (VR) locomotion, known for its efficiency and ease of use, particularly in small physical spaces where users have limited room to move. However, is efficiency the only metric that matters? In this study, we challenge this well-established technique by comparing teleportation with an alternative approach for navigating constrained spaces: Walking-with-Portals. We conducted a user study (N = 24) comparing both techniques, collecting data on orientation, cybersickness, presence, and immersion. Our results reveal a distinct trade-off: Teleportation proved significantly faster, more efficient for pathfinding, and induced less cybersickness. Conversely, Walking-with-Portals significantly enhanced users' sense of spatial presence and perceived control over their movement. While a majority preferred Teleportation for the task's efficiency, 91.7% of participants identified Walking-with-Portals as the more immersive technique. Additionally, we establish key design guidelines for intuitive portal placement that allow a large virtual environment to fit within the small play areas (about 2.5 × 2.5 meters) common to home VR users. Our findings suggest that while teleportation remains the default solution in VR locomotion, Walking-with-Portals provides unique benefits that should not be overlooked. This work invites a reflection on locomotion in VR, arguing that the future of VR navigation may go beyond teleport.

In Virtual Reality (VR), navigating small physical spaces often relies on handheld controllers, such as teleportation and joystick movements, due to the limited space for natural walking. However, walking-based techniques can enhance immersion by enabling more natural movement. This paper presents three room-connection techniques - portals, corridors, and central hubs - that can be used in virtual environments (VEs) to create "impossible spaces". These spaces use overlapping areas to maximize available physical space, promising for walking even in constrained spaces. We conducted a user study with 33 participants to assess the effectiveness of these techniques within a small physical area (2.5 x 2.5 m). The results show that all three techniques are viable for connecting rooms in VR, each offering distinct characteristics. Each method positively impacts presence, cybersickness, spatial awareness, orientation, and overall user experience. Specifically, portals offer a flexible and straightforward solution, corridors provide a seamless and natural transition between spaces, and central hubs simplify navigation. The primary contribution of this work is demonstrating how these room-connection techniques can be applied to dynamically adapt VEs to fit small, uncluttered physical spaces, such as those commonly available to VR users at home. Applications such as virtual museum tours, training simulations, and emergency preparedness exercises can greatly benefit from these methods, providing users with a more natural and engaging experience, even within the limited space typical in home settings.

Virtual Reality (VR) offers an interesting interface for exploring changes in space and time that otherwise could be difficult to simulate in the real world. It becomes possible to distort the virtual world by increasing or diminishing distances, as well as to play with time delays. In this way, it is possible to create different spatiotemporal conditions to study different interaction techniques to analyse which ones are more suitable for each task.