Core technology

VR is a combination of different technology, including computer real time three-dimension image, stereoscopic display, user movement tracking, audio input/output, etc. Computer real time three-dimension image Though it is not a big deal for modern technology to generate sophisticated image, the key part is the image should appear in real time and be refreshed in high frequency. In VR system like flight emulator and racing car emulator, real time image is an essential feature as well as the quality of the image. It is not an easy job to achieve it.

• Display

In VR system, there will be some slight differences between the images seen by user’s eyes. Some systems adopt single monitor, but after the user put on a pair of special glasses, one of his eyes can only see image shown in odd frame, the other eye can only see the image shown in even frame. The slight difference generates the amazing feeling of three-dimension.

• User movement tracking

VR system must be capable to track the movement of the user, especially the head and eyes, to make interaction possible. In an artificial environment, every object has a distinct position according to the coordinate system generated by the computer. The view seen by the user is decided by the position and the direction of the user’s head and eyes. VR technology enables user to get rid of mouse and keyboard and control the change of view via the movements of his head. It is an innovative technology and provide vivid view to the users.

• Sound

Human can determine the direction of the source of the sound according to the difference of the phase and amplitude. Stereo used in cinema and theater relies on different soundtrack played in left and right hand side. In real life, when we spin our head, what we hear in surrounding environment will change accordingly. However, in VR system, due to the common appearance of the VR helmet, the direction of the sound source has nothing to do with the movement of user’s head.

• Feedback of the movement

In a VR system, user can see a virtual object but cannot touch it. It would be a drawback when user wants to reach something but feel nothing. The common solution for this problem is to install some vibration devices in the gloves worn by the user to simulate the feeling of hands.

• Speech Recognition

In VR system, audio input and output is vital for the implementation of interaction with user. Translating speech in computer system remains a challenge, not only should it be efficient but the requirement of correct rate is high. By identifying the speaker before recognizing what he says can save some resource of the computer, but it also raises the requirement.