The Effects of Physical Coherence Factors on Presence in Extended Reality (XR)

This research investigates the influence of physical coherence factors on presence during user-object interactions in XR environments. Physical coherence was defined through four factors (force, occlusion, lighting, and material) and was examined through a perceptual matching experiment, where participants selected factors they intended to improve in a given XR environment to reach an acceptable level of presence. Research outcomes indicate that presence is enhanced with the improvement of physical coherence across all four factors. Also, the transition probability distribution and improvement route derived from a Markov Chain analysis found the force factor to be the most contributing factor when inducing presence, with the occlusion and lighting factor holding the subsequent priority. While most participants chose the force and lighting factor initially, the force and occlusion factors were most likely to be enhanced to the highest for final acceptance. Furthermore, findings suggest that the force and occlusion factors affect interactivity, while lighting affects visual realism of an XR environment. Connecting these findings, it is interpreted that the interactivity has a higher contribution to presence than the visual fidelity of virtual objects and /or virtual environment. Thus, sufficiently realistic and predictable movements of a virtual object can potentially counteract its visual discrepancy from reality. Moreover, this research provides the insight that the degree of interactivity of an XR environment is of essence to generate a high level of presence.