Like most mixed reality systems do use head-mounted displays (HMDs) as the basic tool to immerse the user, MRGIS uses video-based techniques to project graphics images directly onto a lightweight HMD. In this way, users can enjoy a full color (SVGA resolution) comfortable, remote and hands free visualisation of the MR environment. An example of a user wearing an HMD to visualise a 3D map of Southwark (London) is illustrated below.
However, the greatest disadvantages of HMD-based visualisation are the side-effects caused after long usage. For this reason, systems that make use of HMDs usually have a limited time of operation. In MRGIS it was only used for experimental purposes and the standard visualisation mode is the monitor-based visualisation.
The HMD used in MRGIS was developed by Cy-Visor which offers quality viewing in 800x600 resolution and can deliver clear text and graphics. It also includes personal headphones which can be used to deliver full stereo sound.
