As Multi layer PCB factory knows that，As a type of computer simulation system, VR, short for Virtual Reality, can be depended to establish and experience a virtual world. VR leads to the generation of a sense world containing vivid 3D view, sound, touch or smell senses through computer. Based on the highly-authentic simulation environment created by VR technology, users can have remarkably new experience in terms of sound, touch and view senses.

a. Properties of VR

1). Sense of Presence - refers to reality degree users can feel that exists in simulated environment. Ideal virtual environment should reach such a degree that users fail to distinguish reality and simulation.
2). Interaction - refers to users' operating availability on objects in simulated environment and natural degree that users obtain from the environment.
3). Autonomy - refers to movement degree of objects in simulated environment according to real world.

b. Types of VR

1). Immersive VR, also called wearable VR, provides users complete experience of immersion. Depending on HMD (Head Mounted Display) or other devices such as position tracker, data glove and other manual input peripherals or devices. Through offering isolated simulation space integrating sound, view and other senses, immersion VR leads users to be totally involved in a feeling of being there and complete immersion.

2). Easy VR, also called desktop VR, implements simulation through PC and degraded workstation with computer display as a window by which users are able to observe the simulated world. Stereo glasses and 3D controller can be used to achieve sufficient interaction between reality and simulation among display and some input devices such as cursor, trackball and space ball. Since participants aren't fully involved in simulated environment, they will still be influenced by surrounding environment.
3). Distributed VR is a type of VR system based on network connection. Multiple users are connected together through computer network and participate in virtual space to go through virtual experience so that virtual reality can be improved to a higher level. In distributed VR system, multiple users are capable of observing and operating the same simulated world through network to achieve cooperative work. A typical application of distributed VR lies in on-line game that is popular around the globe. Numerous players communicate and fight with each other in the same simulated environment to make simulated story go on and on.