How does a see-through HMD work?
See-through head-mounted displays are used in a subset of Virtual Reality applications called Augmented Reality, or AR. AR allows users to see virtual images superimposed or blended with their physical environment. There are two main categories of see-through head-mounted displays used for AR: Optical see-through and Video see-through. Most AR applications today use optical see-through displays. These displays use mirrors and/or beam-splitters to present a virtual image while the user looks through the eyepieces. The nVisor ST is one example of an optical see-through HMD. Video see-through HMDs are technically not see-through devices. They capture video of the user’s surroundings which is then processed through a computer to mix the virtual images. The composited image is then viewed through standard non-see-through eyepieces. The optional VideoVision module provides video see-through capability for the nVisor SX. Both approaches have merit and the decision which to use depends very mu
