How can the Additional Motion Parallax along the y and z-axis Affect Viewer’s 3D Perception?: A Generic Approach and Evaluation

Light Field Displays (LFD) offer the potential for a true window into a virtual world without any form of headset. However, the vast majority of LFD only provide motion parallax along the x-axis (horizontal) due to its domination of human 3D perception. The additional motion parallax along y and the z-axis are rarely or never achieved and let alone evaluated. This paper proposed the first approach that provided the real full-motion parallax covering the z-axis. Moreover, this generic approach enables on-demand y and z-axis motion parallax on any off-the-shelf LFD. A prototype was created according to the proposed approach, and with the use of it, an experiment with two tasks was carried out among 24 participants. This pioneering study explored the effect of the motion parallax along the additional axes. Subjective and objective metrics were collected to measure participants’ 3D perception on four viewing conditions (LFD with motion parallax along the x-axis, x-and-y-axis, x-and-z-axis, and x-y-and-z-axis). The study manifested three main findings: 1) The additional y-axis and z-axis motion parallax increased viewers’ engagement with the LFD. 2) LFD with full-motion parallax provided the optimal user experience. 3) The additional motion parallax along with the y-axis increased viewers’ user experience more than the z-axis.