For the interaction with the VRGeo Demonstrator, we have developed a combined 3D control and menu system, which was explicitly designed with Virtual Environments and user-friendliness in mind. The menus are composed of equally sized blocks, which either represent a menu item, a widget or a submenu. Another important property of the menus is the sophisticated positioning and resizing system, which finds a suitable position and size for the menu in 3D by considering viewing direction of and distance to the user. The semi-transparency of the menus enables viewing the objects occluded by the menus themselves.
Armin Dressler: Technische Universität Ilmenau, 2007