Underwater immersive virtual reality (VR) environments can reproduce unique VR experiences such as swimming in the sea with beautiful coral reefs and a cage surrounded by sharks. Underwater VR poses new technical challenges to creating user interactions because water and the surround-screen make existing methods for realizing user interaction irrelevant. In this research, we present a potential water flow measurement technology aimed at accessing human-computer interaction in underwater VR. Flow measurement can be realized by using tracer particles that are scattered in fluids. However, existing tracer particles are not suitable for underwater immersive VR because the particles stop users from viewing the content on the screen. Therefore, we propose transparent tracer particles that become invisible in water and polarization-based technologies that enable cameras to track the movement of particles. This technology enables virtual objects in VR to react with the actual movement of water and haptic feedback by creating water flow in the swimming pool. These additions would enhance the illusion of immersion in underwater VR.

Although doing sports and games together is effective to create good social connections, a large skill gap among players reduces the enjoyment in such activities. In this research, we technologically enhance sports and gaming activities in the real world. The gaming environment is aimed at mitigating the differences in ability without reducing the enjoyment. For the initial approach of the research, we implemented a setup for enhancing table games by using a liquid crystals display. The system shows different images to each player using a polarization-based technique. As the application, we implemented an augmented PONG game. The game has a function to support players depending on their scores in the match. This setup can apply to a projector for a wider gaming field for enhancing game activities requiring body movements such as Table Tennis and Air Hockey.