Volumetric displays do not require special 3D glasses.
The term volumetric literally means of, relating to, or involving the measurement of volume. In the field of technology, the term is most commonly used in relation to volumetric displays. Several types of volumetric display technologies exist, but all of them create true three-dimensional images -- which can be viewed from almost any direction -- by illuminating points in space.
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Volumetric displays use thousands of 3D picture elements, or pixels -- known as volume elements, or voxels -- which either emit or absorb light, to create a 3D image. So-called holographic displays create a 3D image by reproducing the bending of light waves around obstacles in their path -- known as diffraction -- in a scene. The diffraction of light is controlled by a series of microscopic patterns on a physical holographic imaging plane.
So-called swept volume displays literally sweep a two-dimensional image, which varies over time, through a 3D spatial volume at a frequency higher than 24 times a second, or higher than the human eye can resolve. The human eye has limits on how fast it can react to changes -- a phenomenon known as visual persistence -- so the human viewer perceives a 3D volumetric image. So-called static volume displays, on the other hand, create a 3D image by directly energizing, or exciting, points in a physical 3D medium, without any mechanical motion.
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The main advantage of volumetric displays over other types of 3D display is that they create true 3D images, which can be observed from multiple angles and depths without viewers needing to wear special shutter glasses or any other headgear. Furthermore, volumetric displays do not require vast amounts of processing power and sophisticated shading effects can be used to reproduce curvature and texture and improve the quality of the 3D image displayed. Volumetric display techniques could be used for data visualization, such as viewing complex biological, chemical and mathematical structures as well as for entertainment purposes, including movies and games.
Traditionally, volumetric displays suffered from problems with displaying shading and completely opaque objects, which are commonplace in the real world. However, these problems have been largely overcome by modifying the input data -- to create what is known, technically, as a lumi-volume -- so that the light waves in the display create additional shading and darkening effects.
