![]() Several studies exist that measured the perceptual limits for curvature gains to remain unnoticed. ![]() The magnitude of a curvature gain is defined as the inverse of the curvature radius.Īs long as the radius of a forced curvature is not too small, users fail to notice the manipulation and assume that the virtual walking trajectory corresponds to the real one. Modern algorithms dynamically apply curvature gains based on a user’s position in the virtual and physical environment with the goal to steer the user away from walls, thus making it possible to explore virtual areas much larger than the available physical space 6, 7, 8. At the extreme, a user could proceed infinitely far straight forward in the VE while walking in a full circle in reality. This causes the user to correct for the rotation by walking on a curved pathway (Fig. Applying a curvature gain induces a rotation of the virtual scenery around a user while (s)he is moving. The focus of the present study is on one key technique of redirection, the so-called “curvature gain” 5. By controlling how real-life movements are mapped onto virtual space, redirection aims at manipulating a user’s physical walking trajectory. Redirection or redirected walking is a software-based approach to addressing this problem 4. Because VEs are often larger in size than the available physical space, collisions with physical boundaries become an issue. Due to the HMD, the user is blind to real world obstacles like walls and other objects in the physical room. While this approach produces the exact sensation of real walking, a new problem arises. Position tracking technology offers the possibility to translate real walking movements into virtual movements 3. While such solutions made it possible to “walk” infinitely far in a VE, they are still a cumbersome approximation to real walking. This crude simulation of locomotion was quickly followed by more sophisticated solutions using treadmill-like devices that allow users to physically walk on the spot in order to move through virtual space 1, 2. Early attempts to overcome this locomotion problem made use of keyboards and joysticks thus engaging the hands for a task meant, in reality, for the legs. While virtual worlds can easily be expanded infinitely, physical locomotion remains constrained by the dimensions of the available room. It concerns the user’s navigation through large VEs. There is, however, one obstacle to a full-blown immersion, dubbed the “locomotion problem”. Virtual reality (VR) applications using head mounted displays (HMDs) allow users to deeply immerse in a virtual environment (VE). We discuss how future interdisciplinary studies, merging the fields of virtual reality and psychology, may help improving virtual reality applications and simultaneously deepen our understanding of how humans process multisensory conflicts during locomotion. ![]() This supports the interpretation of users’ neglect of redirection manipulations as a “visual capture of gait”. The performance in the rod-and-frame test, a classical measure of visual dependency regarding postural information, showed the strongest relation to redirection detection thresholds: The higher the visual dependency, the higher the detection threshold. We report relations between individual thresholds and measures of multisensory weighting (visually-assisted postural stability (Romberg quotient), subjective visual vertical (rod-and-frame test) and illusory self-motion (vection)). Addressing this question, we administered several perceptual-cognitive tasks to healthy participants, whose thresholds of detecting redirection in a virtual environment were also determined. An important yet unsolved question concerns individual differences in the ability to detect redirection. Apart from its applied relevance, redirected walking is an attractive paradigm to investigate human perception and locomotion. This is achieved by manipulating users’ walking trajectories through visual rotation of the virtual surroundings, without users noticing this manipulation. Redirected walking allows users of virtual reality applications to explore virtual environments larger than the available physical space.
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