Another work was the VRGeo Demomstrator Project,For the interactive analysis of complex deological surfaces and volumes in an iimmersive VR srstem through co - located collaboration [Simon,2005]. The authors present a new interaction paradigm that allows multiple users to share a virtual space in a conventional single-view stereoscopic projection - based display system,with each user manipulating the same interface and having a full first - person experience in the environment.