In this report, the virtual reality system based on a personal computer is proposed. The system is suitable for personal use, and can display visual, auditory and haptic information at the same time. To display haptic information, we use SPIDAR (SPace Interface Device for Artificial Reality). The system is applied to training machine for rehabilitation. System evaluation by actual patients is also reported.
We have developed a computer-based character input system without a keyboard. The handicapped or bedridden patient who cannot use a keyboard are able to input characters with head moving or shaking. The system recognizes and tracks an red marker on his or hers forehead and outputs the maker's two dimensional position. The position of the marker is assigned to computer's cursor. So, people can select characters on the character panel with moving head. Then a selected character with moving head is fixed by timer or external equipment such as a foot pedal of MIDI. The handicapped or bedridden people can write sentences or communicate with other people by the system. The key technique of this system is a tracking algorithm and its hardware. This system has two technical features. The first is a new tracking algorithm using image processing. We proposed a local spiral labeling for a moving object tracking. The second is a new real-time hardware called a FIT board using a new tracking ASIC. The FIT board can be used in a videophone or security system. The FIT board tracks a people's head in front of a videophone or a invader in a restricted area. This character input system is one of the applications of FIT board.
Recently, a virtual reality (VR) technology is used in various fields and makes it possible to represent various objects as three-dimensional computer graphics (CG) and to walk freely through the virtual three-dimensional space. If all of the complicated CG objects are placed in the virtual three-dimensional space, a very long processing time is required for drawing, making it impossible to walk through smoothly. The models used in such a CG are represented with only the surface shape of the objects defined. Therefore, it is impossible to show the internal structure of an object and the view of an optional cross section. The volume graphics technology that represents the inside of an object with graphic models is used to produce and display the contents and crosssectional view of an object. If volume graphics are used, enormous amounts of data must be calculated, making it impossible to produce real-time images. We have developed the technology that places the high-accuracy video images of the inside of an object on top of each other and displays those video images linked to the background CG models. These high-accuracy video images are produced in the virtual three-dimensional space using volume graphics. The technology makes it possible to walk through the virtual three-dimensional space with CG and video images mixed freely. This technology also makes it easy to produce walk-through type VR contents in the educational field such as science and medical care where real images are required.