Immersive virtual environments (IVE) based on head mounted displays (HMD) have proven their utility in various application fields, such as exploration of biomedical data, immersive architectural walk-through and training applications. Nevertheless, the usability of HMD-based IVEs is still a challenging task, especially in application scenarios outside a controlled laboratory environment. One often unconsidered aspect is how the user enters or leaves the IVE, i.e., the transition from the real world to the IVE and back. In a typical setting an user of a HMD-based IVEs enters the virtual world by simply putting the required equipment (e.g., HMD) on and starting a VR-enabled application. Thus, her senses are instantaneously flooded with new perceptual stimuli, usually without any association with the surrounding real world. Even for users, who await with excitement to visit the virtual world, such transition causes a break in the perceptual continuity and may lead to adverse effect, such as disorientation, confusion and discomfort.
One possibility to overcome these limitations is to use subtitutional environments (SE). SE combine the ingenious initial idea of passive haptic with the tremendous amount of work investigating humans’ ability to judge small miss-alignments between haptic, proprioceptive and visual perception of a virtual object in a consistent and sound concept. In particular, a SE superimposes an IVE on top of real environmental objects. This enables the user to use real objects as virtual props, or to estimate accessible interaction space in the surrounding. Nevertheless, the implicit requirement that all real objects, and only these, are present (albeit with different appearance and function) in the virtual world, poses a strong limitation for the design of more general IVEs. The design problem becomes even more apparent when the same (or similar) IVE needs to be deployed in different settings. For instance, a VR test environment may be reused in different research labs and a VR game needs to be usable in the ”living rooms” of different end users. Moreover, the user is left only with the belief, that the virtual objects do really represent some real counterpart and that they are properly registered to each other. The user also needs to somehow remap the virtual objects she is seeing to the real objects she knows,or saw previously.
In order to leverage such effects, we investigate different types of smooth immersion (SI). With a SI user starts the journey into the virtual world from an exact replica of the real world environment (e.g., the VR-lab). This replica is then gradually dissolved to reveal the desired virtual world. The basic idea of such smooth immersion is that it will curb the amount of new sensory information feed to the user, while in the same time it may aid a smooth and consistent remapping of the real surrounding to its virtual counterpart.
In this project we investigate the benefits and the limitations, as well as different implementation options for smooth immersion into a HMD-based IVE. Currently we have conducted a preliminary user study, in which we have evaluated users’ awareness, reality judgment and experience in the IVE, when using different transition techniques to enter it, and received some very motivating results.
D. Valkov, S. Flagge, Smooth immersion: the benefits of making the transition to virtual environments a continuous process