Principle Which capture moving objects’ action and produce closely integrated interaction between participants and projections. Components 1. Signals receiver: catch shooting according to the demand, the video equipment must be high-quality cameras; 2. Core control software: analyzing the updating data, the program is built in the computer system; 3. Imaging: present the images in a specific place by using projector or other imaging equipment. In addition to projector, plasma displays, LCD displays, rear projection screen can be used as interactive image carriers. 4. Auxiliary equipment: such as transmission lines, installation components, audio devices, Infrared lights and so on. Requirements for the environment: No disturbing IR light, irreflexive floor needed. Advantages: There is no physical contact between participants and devices. The interactive system has a good durability, simple maintenance. Application scenarios: 1. Shop, window show, airport, bank, and other crowded place for publishing and sale; 2. Entertainment occasion, bar, KTV, DISCO, dining-hall to intensify the atmosphere 3. Exhibition halls System maintenance: 1. Inspect capturing equipment regularly including powers, location changes, and equipment cleanliness and so on; 2. The projector's cooling and cleaning system.