Afog display,fog screen,vapor screen orvapor display is a system that useshaze machines or water vapor to create a semi-transparent wall, or "curtain" ofsuspended particles which trapped in a thin sheet (laminar flow) of air and are illuminated by aprojector,[1] in order to produce a display whose images seem to float in mid air.[2] Several commercial systems exist, such asFogScreen,Displair andHeliodisplay. There is also an open-source variant being developed called Hoverlay II[3][4]
This system can be expanded using multiple projectors to create a three-dimensional image, thus becoming avolumetric3D display.[5]