Description  Claims  Drawing  Cited references 

US62422384A   [0001] 

Making first steps in VR: Monitoring User Progress in Virtual Travel   [0004] 
Finding hidden objects in large 3D environments: the supermarket problem   [0005] 
Building on Realism and Magic for Designing 3D Interaction Techniques   [0006] 
Exploration and Virtual Camera Control in Virtual Three Dimensional Environments   [0007]