Alternative Methods of Translational Gains by Viewpoint Manipulation in the Pitch Direction

This paper proposes a new method of translational manipulation for redirected walking through pitch-oriented viewpoint manipulation, which is known to change the walking speed of a user. Pitch viewpoint manipulation adds a slope to the virtual reality environment. In reality, walking on a slope increases or decreases the walking speed, and this study conducts an investigation based on the assumption that similar fluctuations would occur in a virtual reality environment. Through an experiment, the variation in walking speed by dynamically manipulating the viewpoint in the pitch direction for a 5 m walking section, and the perception threshold, which is the range in which the viewpoint can be manipulated without being noticed by the user, were investigated. The results showed that the walking speed significantly decreased with pitch gains of -0.5° in the downward direction, and 3° and 5° in the upward direction. It was discovered that perceptual thresholds of 0.17° and -1.12° in the upward and downward directions, respectively, were imperceptible, indicating that the viewpoint could be manipulated without being perceived.