VilmReel: Scrollable Multi-Environment VR with Cross-VE Notifications

Current VR interfaces impose a single-environment constraint, creating significant barriers for tasks requiring concurrent awareness and manipulation across multiple virtual 3D environments (VEs). We present VilmReel, a VR interface that enables interaction across multiple VEs through a scrollable band interface. The interface resembles a film reel, but with each frame showing a stereoscopic VE instead of an image. Users can scroll the band horizontally, maintaining spatial awareness of all environments. Moreover, we propose multi-modal event notifications: spatial audio informs the user of the location and type of an event in an arbitrary VE (e.g., a person speaking or an in-game sound effect). If the event is not in the active VE, a sound effect is added to indicate that the event happened in another VE and directional vibrations guide the user to the corresponding VE. Finally, we detail on lessons-learned designing the system, including various sound effects and visualizations.