Volumetric display

One definition offered by pioneers in the field is that volumetric displays create 3D imagery via the emission, scattering, or relaying of illumination from well-defined regions in (x,y,z) space.

There are numerous potential markets for volumetric displays with use cases including medical imaging, mining, education, advertising, simulation, video games, communication and geophysical visualisation.

One categorization is as follows: Swept-surface (or "swept-volume") volumetric 3D displays rely on the human persistence of vision to fuse a series of slices of the 3D object into a single 3D image.

For example, the 3D scene is computationally decomposed into a series of "slices", which can be rectangular, disc-shaped, or helically cross-sectioned, whereupon they are projected onto or from a display surface undergoing motion.

One of the first references to this type of system is from 1966, in which a vibrating mirrored drumhead reflects a series of patterns from a high-frame-rate 2D image source, such as a vector display, to a corresponding set of depth surfaces.

[9][10] Recent advances have focused on non-tangible (free-space) implementations of the static-volume category, which might eventually allow direct interaction with the display.

[13][14] Later modifications such as the use of a neon/argon/xenon/helium gas mix similar to a plasma globe and a rapid gas recycling system employing a hood and vacuum pumps could allow this technology to achieve two-colour (R/W) and possibly RGB imagery by changing the pulse width and intensity of each pulse to tune the emission spectra of the luminous plasma body.

[15] The display's medium consists of a class of photoactivatable molecules (known as spirhodamines) and digital light-processing (DLP) technology to generate structured light in three dimensions.

The technique bypasses the need to use high-powered lasers and the generation of plasma, which alleviates concerns for safety and dramatically improves the accessibility of the three-dimensional displays.

The unique properties of volumetric displays, which may include 360-degree viewing, agreement of vergence and accommodation cues, and their inherent "three-dimensionality", enable new user interface techniques.

[20] An artform called Hologlyphics has been explored since 1994, combining elements of holography, music, video synthesis, visionary film, sculpture and improvisation.

To-date, occlusion-capable volumetric displays require two conditions: (1) the imagery is rendered and projected as a series of "views", rather than "slices", and (2) the time-varying image surface is not a uniform diffuser.