Virtual reality is a combination of multiple technologies, including real-time 3D computer graphics technology, wide-angle (wide-view) stereo display technology, tracking technology for viewers' heads, eyes and hands, as well as tactile/force feedback, stereo, network transmission, voice Input and output technology, etc. VR egg chair is the most common device that uses virtual reality technology.
Real-time 3D computer graphics. In comparison, using computer models to produce graphical images is not too difficult. If there are enough accurate models and enough time, we can generate accurate images of various objects under different lighting conditions, but the key here is real-time. For example, in flight simulation systems, image refreshing is important, and image quality requirements are high. Coupled with very complex virtual environments, the problem becomes quite difficult. VR competitive games equipment applied this technology,
In the VR system, binocular stereo vision plays a big role. The different images seen by the user's two eyes are generated separately and displayed on different displays. Some systems use a single display, but after the user wears special glasses, one eye can only see odd frames, the other eye can only see even frames, and the difference between odd and even frames is parallax. A three-dimensional feeling is produced.
User (head, eye) tracking: In an artificial environment, each object has a position and attitude relative to the system's coordinate system, and so does the user. The scene that the user sees is determined by the location of the user and the direction of the head (eye).
Virtual reality hood that tracks head movement: In traditional computer graphics technology, the change of field of view is realized by mouse or keyboard. The user's vision system and motion perception system are separated, and head tracking is used to change the image. The perspective between the user's visual system and the motion perception system can be linked and feels more realistic. Another advantage is that the user can not only recognize the environment through binocular stereo vision, but also observe the environment through the movement of the head.
Keyboard and mouse are the most commonly used tools in user interaction with computers, but they are not suitable for 3D space. Because of the six degrees of freedom in three-dimensional space, it is difficult to find a more intuitive way to map the planar motion of the mouse to any motion in three dimensions. Mini 9D VR theater mainly applied display technology.
People can determine the direction of the sound source well. The common stereo effect is achieved by hearing the different sounds recorded at different locations on the left and right ears, so there is a sense of direction. In real life, when the head turns, the direction of the sound heard changes. However, in the current VR system, the direction of the sound is independent of the movement of the user's head.
In a VR system, the user can see a virtual cup. You can try to catch it, but your hand doesn't really touch the cup and it's possible to cross the "surface" of the virtual cup, which is impossible in real life. A common device for solving this problem is to mount some vibrating contacts on the inner layer of the glove to simulate the sense of touch.
In VR systems, the input and output of speech is also important. This requires the virtual environment to understand the human language and interact with people in real time. It is quite difficult for a computer to recognize human speech because speech signals and natural language signals have "multilateralism" and complexity.
There are currently two problems with the use of human natural language as a computer input. The first is efficiency. To facilitate computer understanding, the input speech may be quite embarrassing. The second is the question of correctness. The way computers understand speech is to compare and match, and no one has intelligence.