ABSTRACT
One of the most promising and challenging future uses of head-mounted displays (HMDs) is in applications where virtual environments enhance rather than replace real environments. This is referred to as augmented reality (Bajura et al., 1992). To obtain an enhanced view of the real environment, users wear see-through HMDs to see 3D computer-generated objects superimposed on their real-world view. This see-through capability can be accomplished using either an optical (shown in Fig. 4.1) or a video see-through HMD (shown in Fig. 4.2). We shall discuss the trade-offs between optical and video seethrough HMDs with respect to technological and human factor issues and discuss our experience designing, building, and testing these HMDs.
