3D Displays

3D displays are displays that project images which appear 3-dimensional. Early models require the use of stereoscopic goggles, and will not be truly 3D, but some scientists expect full-fledged 3D displays to hit the market by around 2015. A primary limitation is that holograms are only designed to be viewed from one angle. Research towards making 3D displays possible focusing on head-tracking optics designed to follow a viewer's gaze from around the room, or holographic projections that can be viewed from more than one angle. Holograms and other 3D display attempts have been around for decades, but it will still be a while before we see the technology on shelves.

A company called IO2 technology has created a display called the M2i which can project full-color 3D display images in thin air, available today for about $20,000 US Dollars a unit. The display uses a rear projection system to create images in what they call "transformed air." The images look somewhat ethereal. However, the technology works in all types of lighting. The M2i display is a definite precursor to a more mature 3D display technology.

A more sophisticated 3D display was recently created by scientists at Japan's National Institute of Advanced Industrial Science and Technology. They bill the technology at the "first true 3D display," which uses overlapping laser beams to create tiny plasma flashpoints in the air, the afterglow of which is picked up by human eyes. The system generates as many as 100 airborne dots, and generates plasma "pops" at a rate of 100 times per second. Because the lasers superheat tiny portions of air to produce the plasma, the display creates a constant crackling noise, and can only produce white dots, definite impediments to commercial deployment, but an interesting approach nonetheless.

One difficulty in creating 3D displays is producing high-quality content to port to the displays. Filming a 3D image takes multiple cameras viewing from different angles, and specialized software to convert the 2D images into a 3D spatial map. The practicalities of this could hold 3D displays back for a while even after the technology becomes feasible in principle. The slow adoption rate of HDTVs is also another factor that companies will consider in choosing where to place their research and development dollars. But sooner or later, it seems that civilization will succumb to 3D display technology. What's the future without a holodeck?

3D Photography

Three-dimensional (3D) photography, or stereoscopic photography, is a method of taking photos that presents the images to the human eyes individually, mimicking what the brain does as it compiles imagery from the left and right eyes to interpret depth. There are multiple ways to capture the desired images, different ways to view the images, and a myriad of software available to enhance, process, or display the images. Three-dimensional (3D) photography can be accomplished with a single camera of any variety or with a dual-camera setup and with little to no specialized training.
Action shots are virtually impossible utilizing a single camera for 3D photography. Stationary 3D images can be created, however, by taking one exposure immediately after another with a single lens camera. Utilization of two lenses, whether accomplished with two cameras or a customized dual lens camera, is preferred so that the images can be taken as simultaneously as possible. Two cameras, ideally held together in a chassis, allow for 3D photography of moving scenes. The effect of the images can be enhanced by taking one of the pictures at a different distance or by using a downward angle.
There are a number of ways to view the images created by 3D photography. Sir David Brewster developed the first stereoscopic viewer in 1849 and displayed it at the 1851 Great Exhibition in London. Viewers and various methods of presenting stereoscopic images have evolved since then and have expanded to include digital projection and viewing on a computer screen.

The images can be presented side by side, overlapping, or alternating and are viewed with a binocular style viewer, specialized glasses, or the naked eye. The two most common naked eye viewing methods of 3D photography are cross-eyed and parallel. Other naked eye methods include lenticular and wobble, which is also referred to as wiggle. Binocular viewers allow for the display of images in stereoscopic pairs and can be found in a variety of designs.
One of the most commonly known methods of viewing 3D photography is via the use of anaglyphs. Anaglyph images are composed of two identical images presented in overlapping, or superimposed, red and blue color schemes. These images are viewed using glasses designed to converge the two color schemes to create the 3D impression. Polarization and digital projection are additional viewing methods that require specialized glasses. Viewing 3D imagery on a computer screen can be done utilizing a number of the above mentioned methods, including naked eye, anaglyphic, and polarization.

What Is a 3D Holographic Projection?

A 3D holographic projection is an image projected onto a screen that appears to be three-dimensional, which means it appears as a real object or person. Holograms were first developed on photographic film in the mid-20th century, using laser light reflected off an object. When the developed film was lit with a laser again, the image appeared as an object resembling the original. The image would change as a viewer moved around it, similar to what occurs when looking at real objects.
Later holograms were developed that could be developed using lasers, but were viewable under normal light conditions. These holograms were often used on credit cards or other documents as a security verification image, because they could not be reproduced with a standard printer. This permitted credit card companies in particular to protect themselves from forgeries by developing holographic cards.
The earliest form of 3D holographic projection was often referred to as "Pepper's Ghost". In the 1860s, a stage act by Professor Pepper used a ghostly image that appeared onstage with real actors. After a time the image would disappear, leading many to believe that a real ghost had appeared. The effect was created by a mirror effect created from clear glass.

When a lighted object is placed in front of a flat sheet of glass, the glass can act as a partial mirror, with a dimmer version of the object visible as a reflection. The "Pepper's Ghost" was created by an angled sheet of glass placed on stage between the actors and the audience. When a bright light illuminated an offstage actor, the image was reflected off the glass and toward the audience, which created a ghostly image that appeared to be present on the stage. Attempts to improve the image failed due to the limits of visibility from normal glass and light sources at the time.
In the 20th century, the development of high definition television and projectors created a new form of 3D holographic projection. The new technology used a light projector that sent still or video images through a magnifier lens and onto a thin reflective film. This technology could be broadcast onto flat or curved surfaces, and allowed people to view others in real-time for video conferencing or stage performances. The projected image is two-dimensional, but the human brain interprets the image as being three-dimensional, making an object appear real.
Another application of 3D holographic projection used laser instead of normal lighting. Standard visible light contains a wide range of light frequencies that are generated by the light bulb and travel in random directions. Laser light is a collimated beam, which means all of the light is traveling in a very narrow beam of a single light frequency. If an object is lighted with a laser, the reflected light sent to a 3D holographic projection screen is highly focused.
A focused laser beam will create a much brighter and sharper image than normal light. The image will also remain in focus if the image size or the distance from the laser projector increases. This occurs because the laser beam is not scattered by distance like normal light, and therefore will remain clear even if the image is enlarged. Applications in the early 21st century were growing in the fields of communications, stage entertainment and three-dimensional advertising.

3D Virtual Reality

3D virtual reality is a type of video game or similar computer software and hardware setup that allows someone to experience three-dimensional (3D) graphics and sounds in an all-encompassing way. This is typically created through a combination of different pieces of hardware, which can include goggles or some other type of visual display, headphones, and various input devices. Computer software then creates images for the display and can track motion and head movements to make the images respond to the motion of the wearer. 3D virtual reality can be utilized in training simulations, though developments have been made in numerous ways to try to utilize this technology in gaming.

The basic idea behind 3D virtual reality is the creation of a virtual 3D space in which a person feels immersed and that he or she can interact with in some way. This is typically achieved by having a virtual avatar for a person exist within a 3D environment, which someone can utilize through first-person perspective. The avatar then acts as the person within 3D virtual reality and moves according to the input from the user or player.

A number of different types of hardware are often used to create 3D virtual reality, beyond the computer equipment needed to run the software for this type of program. Some form of visual display is needed to allow someone to feel as though he or she is within the virtual environment. This can be anything from a series of large wall displays around a person that emulate an environment around him or her to the use of goggles or a headset with displays within them. Headsets are quite popular, as they block out other environmental factors and can include speakers to allow someone to have both visible and audible engagement with the virtual reality.

Some type of input device is also typically used with a 3D virtual reality program, to allow someone to interact with the virtual environment. Headsets can include motion detectors that change the displayed images to reflect movements by the wearer. This allows someone to look around at a virtual landscape by moving his or her head. Handheld input devices can also be used to move the virtual avatar within the space and to interact with objects in the virtual world.

The software used to create 3D virtual reality can vary quite a bit, though it usually renders out 3D landscapes and objects to create a world around the user. Training simulations, for example, can allow someone to learn to fly a plane or perform other tasks in a way that more closely resembles actual conditions. Video games have been experimenting with 3D virtual reality for some time, and continue to try to develop software that would allow for game playing within such a virtual space. Problems have existed in most of these developments, however, which have included everything from poor control and inferior graphics to headaches due to eyestrain.

What Is 3D Virtual Reality?

3D virtual reality is a type of video game or similar computer software and hardware setup that allows someone to experience three-dimensional (3D) graphics and sounds in an all-encompassing way. This is typically created through a combination of different pieces of hardware, which can include goggles or some other type of visual display, headphones, and various input devices. Computer software then creates images for the display and can track motion and head movements to make the images respond to the motion of the wearer. 3D virtual reality can be utilized in training simulations, though developments have been made in numerous ways to try to utilize this technology in gaming.

The basic idea behind 3D virtual reality is the creation of a virtual 3D space in which a person feels immersed and that he or she can interact with in some way. This is typically achieved by having a virtual avatar for a person exist within a 3D environment, which someone can utilize through first-person perspective. The avatar then acts as the person within 3D virtual reality and moves according to the input from the user or player.
A number of different types of hardware are often used to create 3D virtual reality, beyond the computer equipment needed to run the software for this type of program. Some form of visual display is needed to allow someone to feel as though he or she is within the virtual environment. This can be anything from a series of large wall displays around a person that emulate an environment around him or her to the use of goggles or a headset with displays within them. Headsets are quite popular, as they block out other environmental factors and can include speakers to allow someone to have both visible and audible engagement with the virtual reality.

Some type of input device is also typically used with a 3D virtual reality program, to allow someone to interact with the virtual environment. Headsets can include motion detectors that change the displayed images to reflect movements by the wearer. This allows someone to look around at a virtual landscape by moving his or her head. Handheld input devices can also be used to move the virtual avatar within the space and to interact with objects in the virtual world.

The software used to create 3D virtual reality can vary quite a bit, though it usually renders out 3D landscapes and objects to create a world around the user. Training simulations, for example, can allow someone to learn to fly a plane or perform other tasks in a way that more closely resembles actual conditions. Video games have been experimenting with 3D virtual reality for some time, and continue to try to develop software that would allow for game playing within such a virtual space. Problems have existed in most of these developments, however, which have included everything from poor control and inferior graphics to headaches due to eyestrain.

Holographic Display

A holographic display is a kind of three dimensional display, but unlike the three dimensional effects achieved with traditional three dimensional technologies, it incorporates a true parallax element. This means that the viewer can move around the image in any direction, and the image maintains its integrity. This technology can be used in two ways. It can be used to create a holographic image on a flat display surface that does not actually exist in three dimensions, but appears to, without any special glasses or other viewing aids. A second application is to create a virtual image in space that actually occupies three dimensions and may be viewed from any direction as though it were an actual physical object.
Flat holographic display technology is not new and has been used for decades to create the illusion of three dimensional images on flat surfaces. Like all holographic displays, such an image requires no special glasses or other special equipment to view. It appears as a three dimensional image that appears to rotate in space as the viewer's perspective changes. The most advanced versions of these displays are able to depict three-dimensional versions of aerial maps commonly found on the Internet. When laid on a surface and lighted, the objects and buildings appear to have actual substance, and the viewer can move around the perimeter of the image. Objects and images maintain their perspective regardless of the angle or direction of viewing.
New advances in technology have made possible the true three dimensional holographic display. This technology uses special rotating mirrors and laser projectors to create an image that occupies space in three dimensions, but has no physical substance. A viewer of such a display can move about the object in any direction and the object will maintain its integrity exactly as a real object would. For example, a holographic display of an apple can be viewed in exactly the same way as a real apple on a pedestal. Changing the viewing perspective in any direction will visually result in a perception of the image in exactly the same way as if it were a real object.
Research continues on both versions of this technology. In 2011, researchers at the Massachusetts Institute of Technology (MIT) have also developed an early prototype for a three dimensional holographic television display. This would incorporate existing television technologies to allow three dimensional television that exhibits true image integrity and requires no special glasses. As a viewer changes his position relative to the screen, the holographic display appears to retain its shape and depth, unlike current three dimensional television images, which quickly distort and lose their ability to accurately depict three dimensions when the viewer's perspective moves beyond a critical angle.

3D Projection

Three dimensional, or 3D, projection, which is often called 3D projection mapping, is the transference of three-dimensional data onto a two-dimensional plane. Scientists, engineers, and designers often make use of this type of mapping system when making computer or pen and paper models of three-dimensional objects. Objects may be drawn to scale or with perspective, but both qualities cannot be kept intact after translating three dimensional coordinates into two dimensions. Though 3D projection usually refers to the modeling itself, it can also refer to the projection of images that appear to be in three dimensions, such as those seen in 3D films.

By its nature, the act of transferring three dimensional information onto a two dimensional plane means that something must be lost. There are two main ways to use 3D projection, and each has its own positive and negative qualities. One way to project a three dimensional image onto a two dimensional surface is by using perspective. Perspective makes an image look to the eye as if it were three dimensional, though the sizes of the parts of that object, if measured, would not be proportionally correct. The other way to use two dimensions to represent three is to use a system called orthographic projection. In this system, the measurements are accurate but the object will not look like it has depth.

There are a number of uses for 3D projection. Engineering design and drafting both make use of three dimensional coordinate systems in the design of buildings and structures. Computer graphics also use 3D projection when modeling a three dimensional object or environment in the two dimensional space of a computer screen. Science and mathematics may also use this type of projection when modeling or graphing various natural phenomena and equations.

3D projection can also refer to the projection of two dimensional images onto a screen in such a way that they appear to the viewer to exist in three dimensions. The technology to make a two dimensional image appear to have depth has been available since the 1920s, and though there have been many improvements, the basic principles are the same. Instead of one image, two images that overlap slightly are placed on a screen at the same time. When a person is wearing special glasses, either color filters or polarized filters, each eye is only able to see one of these images, and the brain translates the information received by each eye into one three dimensional image.