A volumetric display is a type of graphic display device that can create three-dimensional (3D) images. Images from volumetric displays are truly 3D and have width, height, and length. This makes the images more realistic than simulated 3D graphics, such as those that are shown on a standard flat display screen.
Unlike some traditional 3D graphics, volumetric displays do not require special goggles in order for a 3D image to be seen. The three-dimensional graphics created by this type of display can be seen from any angle. Multiple people can view the image of a volumetric monitor at once, and each viewer can observe the picture from a different perspective. This provides viewers with a very natural viewing experience.
Several different methods can be used to create volumetric graphics. One type uses a technique known as a "swept surface." A swept surface volumetric display employs a visual trick called persistence of vision. The human eye views rapidly moving light as a single image, such as the arc of light that appears when a flashlight is waved quickly through the air. Many volumetric devices use fast-moving lit surfaces to create the illusion of a solid shape.
A second method that is used to display volumetric 3D images is called static volume. In this technique, there are no moving parts in the visible area of the display. Instead, mirrors and lenses are used to direct a bright light such as a laser. Very fast pulses of laser light are aimed at different points in the air. Persistence of vision convinces the eye that these points of light are part of a single solid object.
Volumetric display devices have many different applications. These types of displays are useful for medical training and diagnosis. A 3D display, for instance, can show a realistic image of a skull or heart and allow a group of medical students to study the structure from every angle. Volumetric displays are also useful for architects and builders, who can visualize a construction project in three dimensions.
Research is ongoing regarding methods of interacting with volumetric displays. Sensors may allow users to manipulate and adjust the graphics without the use of a keyboard. A camera connected to a display, for example, can track hand motions and rotate images as needed. These advanced methods of volumetric interaction allow for a very intuitive experience, where users can literally reach out and touch three dimensional images.