Quantifying Self-motion Perception of Motion Effects in 4D Experiences

Abstract

When perceiving motion effects created for 4D content, we cannot perceive the motions exactly as the designer intended due to noises present in our senses/brains. To provide better 4D motion experiences in consideration of the perceptual noises, we quantified the human perception of passive self-motions. In this thesis, we studied three different topics: (1) The smallest intensity of motion that can be detected (Absolute threshold) for all six degrees of freedom of the motion chair, (2) The smallest difference in intensity between motions required for reliable perception (Difference threshold) for several motion frequencies, (3) How brains combine visual and vestibular information for the scenes similar to 4D Rides. Participants identified the direction of motion in the experiment (1) and compared the intensities of two motions in experiments (2) and (3). In both rotation and translation of chair motion, we found that the motions about an earth-vertical axis (Yaw and Heave) were less sensitive than those of the other axes. Also, the ability to differentiate motion intensity had a negative correlation with frequency at 0.2-0.8 Hz. In 4D rides where pitch is mainly used, participants believed in the vestibular and visual cues at a 7:3 ratio (vestibular capture), even though there were individual differences. These results can be useful for designing motion effects while considering human perception to motion feedback.