SHELL4D
Perceptual/Affective Understanding of Motion Effects
Perceptual/Affective Understanding of Motion Effects
We studied the perceptual and affective characteristics of motion effects with an emphasis on obtaining perceptual spaces and affective spaces.
Publications
Virtual Reality 2023
Sensory Cue Integration of Visual and Vestibular Stimuli: A Case Study for 4D Rides
Jiwan Lee, Sung H. Han, and Seungmoon Choi
This paper investigated human self-motion perception through the visual and vestibular sensory systems under the context of virtual reality (VR) and 4D. Consistently with general 4D riding applications, we designed and used sinusoidal motions as stimuli, which resembled simple roller coaster rides moving in three directions of pitch, surge, and heave. Based on the Bayesian integration model, we experimented to determine the uncertainty involved in the two sensory systems and their relative contributions. We factored in small sensory discrepancies between the visual and vestibular cues and visually noticeable obstacles that could distract viewers. We found that the vestibular system contributed more dominantly to the perception in the ratio of 7:3 than the vision, demonstrating vestibular capture. We also discovered that the visual scenes that contain eye-catching elements and pure optical flows can hamper self-motion perception while increasing the perceptual uncertainty. Our findings can serve as a basis for designing motion effects for VR and 4D applications, especially in situations where multiple sensory systems are stimulated simultaneously.
TOH 2022 / WHC 2023 (Poster)
Motion Effects: Perceptual Space and Synthesis for Specific Perceptual Properties
Sangyoon Han, Jiwan Lee, Gyeore Yun, Sung. H. Han, and Seungmoon Choi
A motion effect, the vestibular stimulus generated by a moving chair, is crucial in improving user experiences in many virtual reality (VR) and entertainment applications. However, the perceptual characteristics of motion effects remain unexplored to a great extent. This paper constructs a perceptual space that accounts for many motion effects based on their perceptual distances and then demonstrates smooth–rough and irregular–regular as its two primary perceptual dimensions. An authoring space is constructed with these two pairs as the axes. We also present methods for synthesizing new motion effects with a specific property in the authoring space. The contributions of this work are with new insights into the perceptual characteristics of motion effects and the first design methods of motion effects achieving desired perceptual properties.
VRST 2021
Absolute and Differential Thresholds of Motion Effects in Cardinal Directions
Jiwan Lee, Jaejun Park, and Seungmoon Choi
In this paper, we report both absolute and differential thresholds for motion in the six cardinal directions as comprehensively as possible. As with general 4D motion effects, we used sinusoidal motions with low intensity and large frequency as stimuli. Hence, we could also compare the effectiveness of motion types in delivering motion effects. We found that the thresholds for the z-axis (up-down) were higher than those for the x-axis (front-back) and y-axis (left-right) in both kinds of thresholds and that the type of motion significantly affected both thresholds. Further, between differential thresholds and reference intensities, we found a strong linear relationship for roll, yaw and, surge. Compared to them, a relatively weak linear relationship was observed for the rest of the motion types. Our results can be useful for generating motion effects for 4D contents while considering the human sensitivity to motion feedback.
CHB 2021
Investigating 4D Movie Audiences’ Emotional Responses to Motion Effects and Empathy
Dawoon Jeong, Sung H. Han, Dongyeong Jeong, Kimin Kwon, and Seungmoon Choi
Designing 4D effects corresponding to audiences’ emotional responses is important because 4D effects are critical components of 4D movies that provide rich emotional experiences. The recent increasing popularity of 4D content has led to the development of motion effect technology, which involves motions of the chair according to the scene. However, it is difficult to find studies that systematically investigated the influence of motion effects on audiences’ emotional responses. This study investigated the emotional responses of a 4D movie audience to motion effects according to their level of empathy. Participants (mean: 25.0 years, standard deviation: 5.0) with varying levels of empathy watched movie clips provided with or without single pitch motion effects. The degree that the motion effect and empathy affected the elicited emotions differed depending on the emotion type. For example, participants with high empathy reported stronger intensity of fear when short and weak motion effects were exhibited than when there was no motion effect. Distinct motion effect design guidelines that can be adopted to enhance audiences’ emotional experiences were proposed. The findings can be referred to when investigating the emotional responses of 4D movie audiences.
International Journal of Industrial Ergonomics 2021
Investigating Perceived Emotions and Affects of a Scene, and the User Satisfaction with Motion Effects in 4D Movies
Dong Yeong Jeong, Sung H. Han, Seungmoon Choi, Dawoon Jeong, and Kimin Kwon
The primary objective of this study was to investigate the intensity of perceived affect and emotion of a scene in relation to individual empathy ability and the rotation angle of a seat's motion caused by 4D movie motion effect. The secondary objective was to identify the causal factors that affected satisfaction with a motion effect. Although 4D movies have received increasing attention from the users of audiovisual content, user-centered research related to motion effects has rarely been conducted. Thirty-six participants who were grouped according to their empathy ability, viewed 10 4D movie clips and answered 2 questions related to 1) the perceived affect and emotion felt from the scenes and 2) satisfaction with the motion effects. The participants who had a high empathy ability indicated a stronger perceived affect and emotion during a scene than the participants who had a low empathy ability. A motion effect elicited different perceived emotions and affects between the two groups. The perceived temporal appropriateness, physical appropriateness, understandability, and disturbance of a motion effect affected the participants' satisfaction. This is a pioneering research related to the motion effects of 4D movie; therefore, these results could be helpful in providing insight for 4D effect designers of contents industry.