Enhancing Multisensory Experience in CAVE Virtual Reality Through Olfactory Sensing

The integration of olfactory feedback into Virtual Reality (VR) applications remains significantly underexplored compared with other sensory modalities, particularly within room-scale Cave Automatic Virtual Environments (CAVEs), where related research is even more limited. To address this gap, this paper presents Scentree, a custom olfactory system capable of delivering scents in real time based on user interactions, along with Smelling Ancient Greece, an olfactory-enhanced VR experience developed for integration within our CAVE system. Central to the proposed approach is the concept of the Diegetic Olfactory Feedback Loop, which reframes olfaction from a passive ambient effect into an active, interaction-driven feedback mechanism embedded within the narrative context of the virtual environment. To evaluate the system, we conducted a technical performance assessment and an exploratory user study (N=51) examining participant perceptions of immersion, presence, perceived realism, usability, and overall user experience. The findings support the feasibility of interaction-driven olfactory feedback as a multisensory design approach for CAVE environments and provide a foundation for future controlled investigations of olfactory feedback in immersive VR.