Immersive Technology

Immersive Technology

• Introduction

• Outdoor tactical training system using mixed reality environment to improve football player performance 

The field of sports analysis and prediction is experiencing rapid growth, incorporating diverse perspectives to interpret various scenarios. Many sports teams invest in training programs to improve their performance in competitions. Given the high costs associated with these programs, it is essential to optimize resources to enhance training effectiveness. This study introduces a football training system utilizing Mixed Reality (MR) technology, applicable in both indoor and outdoor settings for game analysis and tactical training. The system encompasses three key scenarios: set-piece training, tactical drills, and player information relevant to match situations. Two experimental setups were employed: one utilizing a Head-Mounted Display (HMD) for MR-based training and the other using a tablet interface. Evaluation of the system involved a 5- point Likert scale questionnaire to assess immersion and discomfort, as well as tests to measure spatial perception and decision-making skills across the scenarios. Results indicated that in the MR-based training environment, the Immersion Experience Questionnaire (IEQ) score improved by approximately 1.39, the Simulator Sickness Questionnaire (SSQ) score increased by about 1.33, and response time-based evaluations demonstrated enhancements of around 1.16 times in spatial perception and 1.25 times in decision-making. These findings suggest that MR-based training environments offer players heightened immersion and realism, enabling them to analyze situations freely without spatial or temporal constraints. Leveraging this technology can significantly enhance players' training outcomes. 

• Constructing physical space design for high color gamut in mixed reality environment 

This paper presents a physical space design methodfor mixed reality-based immersive environments by improving the color rendering of optically visible head-mounted displays. In OST-HMD, the phenomenon that the light of the external environment is combined with the enhanced image occurs, which reduces the visibility of the content. Moreover, previous studies to solve this problem required additional optical components or performed only simple verification. Proposed physical space was designed using black curtains, blinds, low-reflection structures, and adjustable lighting. The physical space can be adapted to the intended use of the physical space through physical transitions for multiple users without additional optics. To verify the usefulness of this environment, we measured the color gamut and intensity spectrum in three experimental environments. Also, we analyzed the factors that change the color gamut according to the components and the surrounding environment. As a result, the color gamut improved by up to 4.7 times from 19.92% to 93.53% based on the environment and improved by up to 4.1 times from 21% to 86.29% depending on the location. The experimental results revealed that the presented method could reduce the factors that degrade the color gamut within all measurement locations and significantly improve the color gamut

• Optical see-through head-mounted display including transmittance-variable display for high visibility 

This paper presents an optical see-through head-mounted display (OST-HMD) that can provide a highly immersive augmented reality (AR) environment. Because visibility of objects is degraded by external light and because projection optics cannot represent black color, the reality of AR content is reduced. To solve this problem, we adopted an additional transparent display to adjust the transmittance of exterior light. This adjustment is achieved using a guest–host liquid crystal (GHLC) to provide transparency in the initial state and opacity when voltage is applied. To verify the display’s usefulness, we measured ambient contrast ratio (ACR) and color gamut under various ambient light conditions after attaching the GHLC panel to the existing OST-HMD (Microsoft HoloLens). Under typical office illumination, use of the GHLC panel increased the ACR by 4.67 times, and the color gamut by 2.87 times compared to the OST-HMD without it. Under high illumination the panel increased the ACR by 1.54 times and the color gamut by 16.16 times. The proposed method significantly improved the ambient contrast ratio and color expression, and yielded a flexible way to customize existing OST-HMDs by adding a detachable display.

• A structure of optical see-through head mounted display 

The AR display is one of the most promising types of displays and it can induce wider collaborations between the display and contents industries, which would create new applications and markets. However, existing AR HMDs still have various challenging points and we proposed the new optical see-through HMD optical structure for improving mobility, weight, burden on skin, and FOV. Our approach is based on the glasses-type transparent projection optics and pinhole array. We used the ray tracing software to model the HMD and performed optical simulation to review overall performance. We will optimize pinhole structure for higher aperture ratio and waveguide grating structure.