Category:

# What Is a 3D Projection?

Article Details
• Written By: C.B. Fox
• Edited By: Susan Barwick
2003-2017
Conjecture Corporation
 Some 30 to 40 million people live in caves and subterranean dwellings in the mountainous regions of northern China.  more...

 October 22 ,  1962 :  US President John F. Kennedy ordered an air and naval blockade in Cuba.  more...
wiseGEEK Slideshows

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.

## Recommended

 SarahSon Post 4 I have a projector that we often use to watch movies when the whole family is together. We have a large wall in the basement where we project the movie to. The quality is good and it is nice to have a big area for everyone to watch the movie on. Having a 3D projector would be really awesome. I am sure that eventually this technology will not be as expensive as it is right now, but that might be a few years away. If we want to watch a 3D movie now, we just go to the movies and put on our glasses. There is something that is a lot of fun and more interactive about watching movies in 3D. nony Post 3 @hamje32 - I think that the answer to your question may lie with some of the newer 3D projection systems. Units like the Panasonic 3D projector have the ability to convert 2D movies into 3D movies. Don’t ask me how they do it, but they claim they can, and soon I think other manufacturers will follow suit if they have not done so already. The only problem is that this is projection technology not flat panel technology. I’m not sure how it would affect the overall quality of the picture. I think that flat panel images look better, especially the newer LED units. hamje32 Post 2 @MrMoody - I look forward to the day when I can buy 3D projection TVs and bring that experience into my living room. Right now the units on sale are still way too pricey for my pocketbook, but I believe that they will come down in price as the technology becomes cheaper to produce and more of the units get sold in the mass marketplace. One thing to consider is what this will do to TV programs that have not been shot in 3D. I think the older films will still be 2D viewing experiences. I expect that it will be decades before almost everything we see on television is in 3D. MrMoody Post 1 I love going to 3D movies with my kids and watching big screen action flicks with those 3D glasses on. I don’t fully understand the technology that makes it happen. I think that they use different cameras to film a scene in various layers, so to speak, and then in the theater the layers are merged together. I love the real, engaging experience it gives to the movie, making it seem like I am there, part of the action. Combine that with the surround sound system, and you feel like you have been truly transported into another time and world. Sometimes we keep the 3D glasses, just as souvenirs (you pay for them, after all). Other times we just dump them in the recycle bin. For light, flimsy throwaway materials, they sure are impressive in what they can do.