Objective quantification of dynamic spatial distortions for enhanced realism in virtual environments

With the rapid advancement of innovative technologies and the increasing demand for the Metaverse, accurately replicating the real world in virtual environments is becoming crucial. Static spatial distortions integrated with motion will lead to dynamic spatial distortions, which are known to contribute to visually induced motion sickness (VIMS) symptoms. Accurate quantification of these distortions is essential for effective optimization for enhanced realism in virtual environments. This study proposes an Index of Spatial Structure Similarity (ISSS) based on elastic potential energy for the objective quantification of static spatial distortions in virtual environments. This full-reference evaluation method uses perceived real-world objects as the benchmark. Systematic perception experiments were conducted to validate the proposed ISSS method, which demonstrated superior performance in evaluating perceived distortions in virtual environments compared to existing methods. Additionally, dynamic spatial distortion indexes, defined as the first and second derivatives of the ISSS with respect to time (representing velocity and acceleration of spatial distortion), were introduced. This objective quantification method considers human factors comprehensively, potentially mitigating the VIMS-related effects of spatial distortions.