How 3D glasses work. User tips

3d is an abbreviation for the term three-dimensional or three-dimensional, that is, three-dimensional. The ordinary world around us is also three-dimensional. The eyes, observing what is happening around, perceive the surrounding objects, which are at different distances from them. Since a person has two eyes, each of them sees an object from its own angle. Two slightly different images are sent to the brain, where they are immediately analyzed. As a result of a complex, but very fast recalculation, the brain produces a three-dimensional image that allows, for example, to estimate whether an approaching car is far or close, you can already cross the road, or it is still worth waiting. 3D technology uses a very similar principle; when watching a movie, the eyes constantly get two different pictures of the action taking place on the screen. It should be borne in mind that when watching a regular film, 24 statistical frames per second are scrolled in front of the viewer. The brain needs some time to process each of them, and while it does this, the previous frame is replaced by the next one, creating the impression of movement. In a 3d movie, essentially the same thing happens, only the number of frames is doubled. The eyes are offered 48 images per second, alternating left-right, left-right. The picture for the left eye is broadcast on a slightly different light wave than that for the right one. If you just look at the screen, you will not see anything but a muddy, rippling picture. Special glasses are equipped with lenses with built-in polarizing filters capable of transmitting light beams of a certain length. Each eye sees only "its own" picture, forwards information to the brain, and that, according to a familiar, long-established algorithm, models a three-dimensional image from the received frames. 3d glasses have already become a common attribute of the modern viewer, but this does not mean at all that from now on it will be possible to watch movies only with them. Technology is constantly evolving and perhaps in the near future there will be another way to polarize the image. Three-dimensional cinema will move to a new stage of development, will become even more voluminous, interesting and exciting.

3D Printer Construction

A 3D printer with FDM printing technology consists of a metal body (frame), a compartment for securing a spool of filament, an extruder and a desktop. Single-extruder 3D printers can print single-color objects, multi-extruder printers multi-color. The more extruders a printer has, the more expensive it is. Electronic filling and heating and cooling system are hidden under the printer body. Some models have LCD displays for displaying current print information and USB ports.

Consumables for 3D printing

A typical 3D printer with FDM printing technology uses thin polymer filaments with diameters of 1.75 mm and 3 mm to work. Such filaments are most often made of PLA or ABS plastic, but there are also combined materials with the addition of wood fibers, nanopowders, biodegradable particles, phosphorizing pigments and other components. The yarns are supplied in spools weighing from 0.5 kg to 1.5 kg. A spool of polymer filaments is placed in a special compartment of the 3D printer, and the end of the filament is fed into the extruder nozzle.

3D modeling of an object

Before you can 3D print a 3D object, you need to create a digital version of it in a 3D modeling program. You can use the ready-made samples that are available on open access on the Internet, or prepare 3D models for printing yourself. The prepared model is loaded into special program to generate a G-code that divides the object into thin horizontal layers and forms a chain of commands that the printer understands. The finished object is sent to print.

Layer-by-layer formation of an object

A 3D printer with FDM printing technology forms physical objects layer by layer, squeezing a thin stream of molten material onto the working platform. The printer moves the extruder exactly according to the digital model, so the printed physical object fully matches its virtual prototype. Most often, the printer's extruder, from which the soft plastic is squeezed out, moves while working on a stationary work platform, but there are devices in which both the extruder and the work platform are movable. The printing process begins with the bottom layer, after which the printer applies the next layer on top of the first. Melted plastic, getting into the working area, cools and hardens very quickly.

3D printing of support structures and object finishing

To prevent the object from deforming during printing, the 3D printer prints supporting structures (aka support structures, support structures). Such structures are not always printed, but only if there are voids or overhanging parts in the object structure. Imagine you want to print a plastic mushroom on a thin stem. With the base of the leg, it rests on the desktop, no support is needed here, but for the edges of the cap, which seem to hang in the air, such support will be simply necessary. After printing, the support structures can be easily removed by hand or cut with a sharp blade or knife.

The idea of 3D television is as old as the world of television and film. The desire to get a three-dimensional image and create the illusion that the image on the screen is something more than just a two-dimensional picture has existed since the very inception of cinematography and television broadcasting.
Unfortunately, 3D cinema and 3D television have always remained at the level of easy infatuation. And the problem has always been that finding solutions to make 3D work seemed like a complete waste of time. With the advent of HD screens, the situation started to improve. In this article, we will look at what modern 3D TVs look like, consider the principles of their operation, and also help you decide on the most suitable type of such TVs for you.

What is 3D and how is it filmed?

The production of 3D content, by and large, happens exactly as you can imagine it. One camera is used to shoot a 2D film, and two cameras are required to produce a 3D film. The goal is to capture two different and slightly separate images, which can then be used so that the left and right eyes can receive a little different pictures happening. This action, in fact, repeats the way we see the natural three-dimensional picture of the world.
To carry out such a "double" shooting, many television and film companies use special equipment that ensures the simultaneous operation of two cameras. The device is equipped with a precision control system that allows you to tune and tune cameras for smooth operation. This process in itself is quite complicated, in addition, it requires that the cameras and, first of all, their optical components, be almost identical - this is what will allow you to get the best result. There are also several camcorders on the market equipped with a dual lens system. In particular, such cameras - for both professional and amateur photography - are supplied by Panasonic and Sony.

There are, of course, other ways to shoot 3D video. For example, an image can be made three-dimensional during post-production, especially when it comes to films with a lot of computer effects and graphics. Insofar as a large number of films are shot using green screen technology, today there are many opportunities to create what is commonly called "artificial 3D".

In all cases, the finished 3D film consists of two separate rows of frames: one for the left eye, the other for the right eye. And the way in which you can watch a given video is determined by the types of broadcasting and viewing systems, which we propose to pay more attention to.

Active 3D technology

Active 3D technology is a system that works on plasma and LCD screens and requires special active 3D glasses to view 3D images. Today, these glasses are quite lightweight and comfortable to use, although some manufacturers have not yet completely brought their design and functionality to perfection. Often, these glasses are equipped with a battery pack that is charged using a plug-in via USB charger devices.
These glasses are based on the use of special lenses with a liquid crystal top layer. When an electric voltage passes through this layer, the lens almost completely loses its transparency; in the absence of voltage, transparency is restored. Nevertheless, some light loss is observed when looking through the lens and when there is no voltage in the liquid crystal layer, which makes the image seen through the glasses on the TV screen slightly darker compared to the original.
To form a 3D picture, the TV sequentially displays frames for the left and right eyes. In this case, the glasses darken the lens for "unnecessary" in this moment eyes. The frequency of such blackouts for each time is 24, 25 or even 30 times per second, so you hardly notice it. However, some people complain about a certain feeling of blinking of the picture - this is precisely the reason for the occurrence of headaches in a small number of viewers using 3D glasses.

The big advantage of an active system is that it delivers true 1080p 3D images. This means that, at least in terms of picture quality this system vastly outperforms passive 3D technology. However, a lot depends on the specific situation, and there are many reasons to fall in love with a passive 3D system.

Passive 3D technology

The biggest advantage of passive 3D technology is that the glasses required to view images in this system are insanely cheap compared to the cost of active shutter glasses.
However, at home use the passive 3D system has one big drawback: the image resolution is half of the image resolution in active 3D technology. The reason for this is that pictures for both eyes must appear on the screen at the same time. On the surface of the liquid crystal screen (there are no plasma panels for passive 3D), there is a special filter that differently polarizes each of the lines that form the image. Thus, the TV simultaneously displays two pictures (for the right and left eyes) that make up a 3D image: one of them contains even lines, the other - odd lines. This process is called "interlaced scanning".
Each of the two lenses that make up the passive 3D glasses are polarized to match the polarization of a particular set of lines on the screen. Thus, each eye sees only what is intended specifically for him. The disadvantage of this technology is that interlaced scanning reduces the image resolution: in passive 3D technology, each eye sees a picture with a resolution of 1920 x 540 pixels.

This way you get full horizontal resolution, but only half the vertical resolution. However, in practice, this is not such a big problem. Most viewers find that passive 3D technology is much more convenient for long-term use, and if there are many fans of watching movies and sports broadcasts around you, this system is the most practical and affordable.

How is 3D video transmitted on TV networks?

Television broadcasters are very limited in terms of their available capacity, so the transmission of a full 3D signal, consisting of two separate streams, is generally unrealistic. To get around this problem, broadcasters use a technique called side-by-side. This method is to take a pair of frames intended for the right and left eyes and place them side by side on the screen so that together they take up exactly the same amount of space as a standard HD image takes on a TV screen. If the viewer watches such a broadcast on the screen of an ordinary 2D TV, then he sees two almost identical pictures, squeezed from the sides so that everything on them seems high and thin. At the same time, the 3D TV divides this "double" frame into two halves and displays them according to the principles inherent in the 3D system used in it.

As a result, we get a 3D image that is technically HD quality, but this quality is significantly lower than the quality of a Full HD 3D movie played from a Blu-ray disc. Nevertheless, the results are quite good and the quality of the 3D picture can be considered acceptable.

How does 3D work on Blu-ray discs?

3D video is in a much better position when it is burned to Blu-ray disc. In this case, you can get a picture in Full HD 3D quality with a resolution of 1080p, but only if you use the right equipment: passive 3D systems cannot display 3D video in Full HD format, only active systems can do this.
With the growing popularity of 3D, a new video compression system has been developed, which can significantly save the amount of memory used. As a result, on standard disc more frames can be placed, which is essential for 3D. This, in turn, means that both rows of frames - for the right and left eyes - can be saved on such a disc in Full HD format, without the compression that we see when broadcasting a 3D TV signal. 3D video recording, even using new system compression still requires a significant amount of disk space, which ultimately leads to a lack of disk space for recording additional materials. However, this is not such a big problem, since you can always put a second, additional disc recorded in HD format in the box. Video consisting of two rows of frames (for the right and left eyes) is displayed on your TV screen according to the system in which it operates.

3D cinemas versus 3D home systems

There are several competing 3D formats used in cinemas. Each of the cinemas is free to choose the system at its own discretion. Most cinemas today use passive 3D systems, which means they don't have to spend money on expensive active shutter glasses for every seating position. At the same time, the first IMAX 3D cinemas used active 3D glasses, so this system is far from alien to cinemas.
For Dolby cinemas, there is a system that is passive in nature, but requires the use of more expensive glasses. The advantage of using this Dolby system is that the theater does not have to replace the screen to use it. Instead, glasses are used with light filters "sharpened" for a certain wavelength of light, as well as a rotating filter installed in front of the projector, allowing you to direct images to the desired eye.
However, by and large, the dominant 3D format for cinemas is the RealD system, which uses polarizing filters and inexpensive glasses. Frames intended for the left and right eyes are projected onto the screen through a special polarizer installed in front of the projector lens. The RealD system provides for separate transmission of frames for the right and left eyes - they are transmitted one after another at a frequency of 144 times per second, and glasses with polarized lenses in front of the viewers' eyes lead to the fact that each eye receives the image intended only for him.

Sony offers a lightweight version of this system, which uses a 4K projector to simultaneously transmit images for the left and right eyes, with a 2K image for each of the eyes.

3D technology that does not require special glasses

TV manufacturers around the world have one common goal: to create a system that does not require glasses when watching 3D video, but at the same time creates a full three-dimensional effect for the viewer. Technically, this is already possible, and televisions using such systems have been on display at CES and other television shows for several years now.
The biggest problem with 3D systems that don't require glasses to watch videos is the quality issue. Of course, these systems are capable of producing a 3D image, but this is far from the picture quality that you would like to see. In addition, to fully immerse yourself in watching such a video, you will have to look at the screen from a certain angle, and experts who investigate the quality of such systems, after testing, complained of slight squint.
However, Dolby is convinced that full-fledged 4K / 3D TVs that do not require glasses for viewing should begin to appear on the market in 2015. Dolby technology, developed in collaboration with Philips, is based on higher-resolution displays used to display 1080p / 3D video. To conduct a technology demonstration at at CES 2014 a Sharp 8K TV was used. Dolby claims that new technology all problems are minimized old systems"3D without glasses", including the need to sit in front of the screen at a certain point.

3D systems based on helmets-masks

One area in which 3D video has tremendous potential is in the use of 3D displays that can be worn on the face like glasses or a helmet. Examples include devices such as the Oculus Rift and Project Morpheus, which are 3D compatible face masks and can be used as virtual reality devices.
In addition to the gaming potential inherent in these devices, due to the presence of separate screens for each of the eyes, it can be assumed that they will be used as devices giving an impressive 3D effect. It may be a little uncomfortable for viewers to wear such a mask on their face at first, and it will take some time to get used to it, but these devices have incredible potential for realistic 3D video.

Is there a future for 3D television?

It is relatively inexpensive to add a 3D function to a TV today. For active 3D systems, the cost of such an improvement does not exceed the cost of active glasses. This means that almost all TVs produced today have 3D built-in. However, this does not change the use of the "3D" label to increase sales.
As Hollywood continues to make films in 3D, this format undoubtedly has a place in the home of the audience. There is a demand for new blockbusters filmed and recorded in 3D, although it is not as big as Hollywood would like.
Perhaps one day, 3D will be replaced by something much better - for example, holographic cinema. However, apparently, this day will not come soon.

Nowadays, everyone has heard about 3D films, and, of course, everyone knows that such films must be watched with special 3D glasses. In recent years, 3D imaging technology has evolved significantly. The quality of the images and the level of realism have increased significantly. Many have already managed to fully experience all the delights of modern three-dimensional films. However, few people think about how 3D glasses work. However, this important point when selecting a 3D TV and 3D glasses.

1. 3D imaging technology

To understand how glasses work, it is worth considering the technology of three-dimensional images. There are currently two 3D imaging technologies:

Active technology (the so-called shutter);
Passive technology (better known as polarizing technology).

Both technologies allow the viewer to fully experience the effect of presence, see a three-dimensional image and enjoy the realism of the picture. Moreover, both technologies are based on the same property - to make each eye see a different perspective of the picture.

For example, in the real world, all objects have three dimensions - height, width and depth. Due to the fact that a person's eyes are located at some distance from each other, each of them sees a slightly different perspective of the subject. This can be seen if you alternately close one eye then the other, looking at an object. Thus, you will see the object from different perspectives. The image received by each eye enters the brain, which processes both images and turns them into one volumetric image. This allows you to roughly estimate its height, width and depth.

All existing technologies of three-dimensional images are built on this. The difference between active and passive technology lies in the method of image separation.

1.1. The principle of operation of 3D glasses with polarized lenses

Polarized 3D glasses work with passive technology. Its essence lies in the fact that the displayed image on the TV screen is divided into two pictures. But how to make sure that each eye sees what it needs? From the very name of the technology (polarization), it becomes clear that this is done using polarization. That is, the image on the TV screen consists of lines, each of which has a certain radiation range.

For example, even lines make up one part of the image, and odd lines make up another. Due to the fact that even and odd lines have different emission spectra, the image is split into two pictures. The 3D glasses have two lenses that also have different polarizations.

In other words, for example, the right lens completely blocks the image of the even lines, but at the same time allows you to freely see the image of the odd lines. The left lens, on the contrary, completely blocks the image of the odd lines, and freely passes the image from the even ones. Thus, each eye sees a different perspective of one image, which, as a result of the brain's work, turns into a three-dimensional image.

It should be noted that to watch 3D movies with the use of polarized glasses, it is not enough to have glasses and a 3D TV set. For this, the video itself must also be three-dimensional. That is, the TV itself is not capable of splitting the image. The video must initially be optimized or be shot with a special camera with two lenses.

1.2. How 3D Shutter Glasses Work

The peculiarity of the active technology of three-dimensional image is that the image on the screen is not split into two pictures. Everyone makes glasses that are equipped with special shutters on the lenses. That is, the TV is equipped with a special infrared transmitter, the same receiver is in glasses. At certain times, the TV sends signals to the glasses, which, in turn, alternately close the shutters on the left and then on the right lens.

Everything happens so quickly that the brain simply does not have time to understand what is happening. However, each eye sees different picture... Next, the brain processes both images and creates the illusion of three-dimensionality.

It is worth noting that to achieve a full-fledged volumetric image, the video must have a minimum of 48 frames per second. This is necessary because each eye must see at least 24 frames per second for the video to be smooth and pleasing to the eye. It follows that the shutter on each lens closes and opens at least 24 times per second. Moreover, than more quantity frames, the smoother and more pleasant the video will be, and the more realistic the 3D effect will be.

2. Active 3D and Passive 3D: Video

Such films and videos are also shot with special cameras that are capable of shooting at a frequency of more than 50 frames per second. The advantage of this technology is the fact that such films can be watched without glasses, like a regular film, only smoother.

Another advantage of this technology is that the viewer sees all 1080. This is achieved due to the fact that the image is not split into lines. This allows you to enjoy 3D movies in FullHD resolution, which in turn significantly enhances the 3D effect, and also makes viewing much more enjoyable.

So now you know how 3D glasses work. This will enable you to do the most right choice when buying, as well as understand the principle of their operation and what films can be watched with a full 3D effect. Many people, not knowing the principle of the technology, often ask the question why 3D glasses do not work?

It's simple, glasses must correspond to the technology supported by the TV. In addition, it is necessary to watch only relevant films that are optimized for the 3DTV standard. Only if you follow these rules will you be able to enjoy a real three-dimensional image to the fullest.

For sure, everyone has heard about the existence of 3D printing, and facts about the new possibilities of this technology are constantly slipping in the news. Not so long ago, three-dimensional printing was used only in production conditions and by a few enthusiasts, today you can easily buy a 3D printer for use in everyday life. With the help of such devices print all sorts of things: from decorative knick-knacks for the home to prostheses, weapons and even buildings. The prospects for 3D printing are so fantastic that few people today can fully imagine them. Until then watching the future come, we study the principles of operation of a 3D printer, its capabilities and advantages, and also figure out which 3D printer to choose for use in everyday life.

Despite the fact that the technology of three-dimensional printing has been on everyone's lips only for the last few years, its appearance is worth looking for in the last century. The pioneer in this field was Charles Hull, which in 1984 developed the technology of three-dimensional printing, and a little later patented the technique of stereolithography, which is now widely used today. At the same time, the company developed and created the first industrial three-dimensional printer, which actually marked the beginning of a new era.

The 90s were the time of the emergence of new developments in the field of three-dimensional printing, thanks to which 3D printers found application in industrial conditions and began to be used for prototyping. The peak of technology development falls on the XXI century, and we ourselves are becoming eyewitnesses of how three-dimensional printing conquers new heights by leaps and bounds. Today, printing can be carried out different materials and not only plastics and metal, but also cloth, paper, ceramics, food and even living cells.

In 2005, it became possible to print in color, and in 2006 a printer was created that can print about half of all its own components. In 2014, the first printers appeared with an almost unlimited print area. With the help of this device, they have already tried to create a full-fledged house using concrete as the main material. It took no more than a day to erect such a structure. Already in 2016, it was presented first building built using 3D printing In Dubai. In February 2017, Russia also unveiled a house printed entirely at the construction site. This year, a six-axis printer was also developed, with which complex elements will be much easier to print without the need for supporting structures. At the moment, the development of printers that can print human organs, prostheses, implants, car bodies and even food.

How does a 3D printer work? Just about complicated

In short, a 3D printer is a device for creating three-dimensional objects by layer-by-layer printing. The range of materials used for printing is constantly expanding and we can safely assume that in the future it will include most of the substances known to us. Bye The most popular print media are thermoplastics and photopolymer resins.

General principle of operation 3Dprinter can be represented as follows:

Printing features depend on the technology used by the printer, so it makes sense to deal with the most common at the moment.

Types of 3D printers and printing features of each

The most commonly used technology todayFDM-prints as wellSLA- printing. What is behind these incomprehensible abbreviations, and what other developments exist in this area?

FDM printing method

FDM-technology(Fused Deposition Modeling) is a filament deposition technology. Today, this method of 3D printing is considered the most common, at the same time it belongs to one of the oldest methods. The principle lies in the layer-by-layer fusing of the plastic filament along the contour of the model.

Thermoplastics are used for printing, which are supplied as coils or rods. Most often typed PLAandABSplastics, including nylon, polyamide, polycarbonate, PET (aka polyethylene terephthalate, which is used to create plastic bottles) and some other substances.

The principle of operation is as follows:

a thread of material is placed in an extruder, where it is melted under the influence of a heating element, and then squeezed out through a nozzle onto the working surface;
the extruder moves along the path specified by the software, and builds the object layer by layer;
if it is necessary to print a complex object, then two types of material can be used: one for the model, the second for creating supports (it is usually soluble, or it simply breaks off the object very easily). Supports need to be printed if the object has elements hanging in the air that cannot be created without supporting elements, the printer will simply have nothing to print on. Everything is clearly presented in the figures below;
after the formation of the first layer, the platform goes down by the thickness of one layer, and the extruder squeezes out a new portion of the material, the process is repeated many times;
at the end of printing, it remains to separate the auxiliary elements.

Model and supporting elements

FDM technology allows the use of production-grade thermoplastics, so printed objects receive excellent mechanical, chemical and thermal strength. The technology is simple, clean and suitable for office or home use.

The same principle is used by 3D-pens. These are actually miniature printers. These pens are designed for drawing three-dimensional drawings. The user can squeeze out instantly solidifying plastic from it, giving it any shape and getting funny products. The device is more intended for pampering, but the idea is interesting, and designers can make many interesting home decor items.

SLA printing method, or stereolithography

SLA (laser stereolithography) technology involves the use of liquid photopolymer resins for printing, which tend to solidify under the influence of a laser or similar energy source. The method allows you to get objects with very precise geometry, because the layer thickness can reach a record 15 microns, therefore it is already widely used in dentistry in the manufacture of implants and in jewelry to create blanks with an abundance of complex parts.

How it works 3D-printers using the method of laser stereolithography can be briefly described as follows:

the working platform is immersed in a bath with liquid photopolymer to a thickness of one layer (15-150 microns);
the impact of the laser on the walls of the future object. The laser beam literally traces the shape of the object on the photopolymer, which, in turn, is set by the software. Laser irradiation causes the material to polymerize at the points of contact with the beam and solidify;
the platform is immersed a little deeper into the bath with liquid photopolymer, and the immersion depth corresponds to the size of the layer. The laser again affects areas of the material that should be part of the printed object;
the process is repeated layer by layer until the modeled object is printed;
the technology also requires the printing of supporting elements. They are made from the same photopolymer;
after printing is complete, the object is immersed in a bath in special solutions to remove excess and clean the model;
final - ultraviolet irradiation for the final solidification of the photopolymer.

The technology is progressive, but it requires the purchase of expensive consumables.

Other types of printing

Less common, but no less interesting and promising are following ways 3D printing:

What is the best 3D printer for home use?

Looking ahead, we note that while the cost of household 3D printers remains relatively high, but in the future we have every chance to observe a reduction in the cost of technology. Remember when you appeared mobile phones, they were also available only to the very wealthy.

The goals of using a home 3D printer can be absolutely anything: from simple pampering and acquaintance with new technology to printing useful small things in the household and prototype models for business. In any case, when choosing, pay attention to the following key characteristics of the device:

print resolution (print accuracy) Is the smallest possible layer height that the printer can print. Specifies the resolution in micrometers (thousandth of a millimeter). The lower the layer height, the less noticeable the transition between them will be, and the smoother the surface of the printed object will be. On the other hand, the smaller the layer, the longer it will take for the printer to print and the higher the load on all of its elements. Resolution depends on technology (SLA allows you to print more accurately than FDM), printhead accuracy, settings software and the selected print media;
Samples with different layer thicknesses
print speed directly depends on the accuracy: the higher the accuracy, the slower the growth rate of the model.
print area tells you what size the object can be printed on the printer. In other words, this is the area of possible reach of the printhead along the horizontal X and Y axes, as well as along the vertical Z axis. Usually, the print area is expressed in three numbers - this is the height, length and width of a conventional parallelepiped (for example, 20 * 30 * 30 mm). For delta printers, the printable area is in the form of a cylinder, so its height and diameter are indicated;
the type of plastic used for printing. In domestic conditions, it is precisely plastics that are used, and these can be ABS and PLA plastics, some models can print with both types of materials. The ability to print with one or another type of plastics is explained by the presence or absence of platform heating. If you have not yet decided what you will print, then it is better to choose a model that supports the maximum number of materials;
manufacturer country... European countries and the USA produce high-quality, but expensive devices, are imported to small quantities, service maintenance is difficult. Chinese devices are inexpensive, the quality is often poor, but in order to indulge, such printers will do. There are also Russian-made printers: with good quality, they please with the possibility of service.

Interesting options for household 3D printers

MakerBot Replicator 2

A high-quality American-made printer, prints using FDM technology, the minimum layer thickness is 100 microns (0.1 mm). Printing area - 285 * 153 * 155 mm, PLA and ABS plastics are used for printing. The maximum printing speed is 40 mm per second, or 24 cm 3 / hour. The body is made of steel, there is an LCD screen, the weight is 11.5 kg. Although the model was released in 2013, it is still actively used for household printing. The cost is $ 3100.

PrintBox3D One

The printer is of domestic production, prints using FDM technology, the minimum layer thickness is 50 microns, the dimensions of the working platform are 185 * 160 * 150 mm. The device prints ABS and PLA plastics, it is equipped with a heated platform. Approximately $ 1,700, designed for educational and design use.

Wanhao Duplicator i3 v2

A budget option for those who want to master the technology and indulge in. Costs about $ 500, prints different kinds plastic with an accuracy of 100 microns, printing area 200 * 200 * 180 mm. The build quality is excellent.

PICASO 3D Designer

It prints using FDM technology, like all household 3D printers today, uses ABS and PLA plastics for printing, incl. nylon. The printing accuracy is 50 microns, the working platform is 200 * 200 * 210 mm, the maximum speed is 30 cm 3 / hour. The device is equipped with a heated platform, cost $ 1,700.

Hercules 3D printer

Not a bad device from Russian company IMPRINTA, prints with different types of plastic, printing accuracy - 50 microns. Heated platform, maximum temperature - 120 0 С. Print speed - 40 cm 3 / hour. Price $ 1150.

As a summary of the main pros and cons of 3D printing

3D printing is a promising direction with great potential. To dot the "i" in the study of the issue of three-dimensional printing, we give its main advantages:

Existing cons:

3D printing is the future of medicine and industry, as well as an opportunity fast creation prototypes and models, which is invaluable for engineering. Who knows, maybe in 5-10 years we will be just as easy to download models of cups or shoes and print them on our own home printer, as today we download and watch films.

Users who are just starting their acquaintance with a computer often wonder what a 3D system is and how it is implemented.

This is a common abbreviation that can now be found almost anywhere - from descriptions of gadgets and games to procedures offered in beauty salons.

This article explains what is meant by such a designation.

Definition

How does 3D stand for, what does this abbreviation mean? The D in this context is the first letter of the word dimensions, which means dimensions.

Thus, the abbreviation 3D stands for three dimensions, it is with this combination that the expression three-dimensional graphics, as well as a volumetric image, can be replaced.

Initially, this abbreviation began to be used specifically for graphics.

This way of image, with the development of computer technology, has replaced the usual two-dimensional construction of the picture.

Especially often the expression "volumetric graphics" is applied to computer games, which create for the user, to a greater or lesser extent, the effect of presence, allow you to realistically walk around objects, inspect them from different angles.

Also given expression is widespread when it comes to movies and televisions. Some films in some cinemas can be shown in the system. Some films in some cinemas can be shown in 3D, with an immersive effect, and some TVs are equipped with this function. There is a slightly different technology here than in computer graphics - both of these technologies will be discussed in detail below.

Other areas of application

This definition is used not only in graphics, it also applies to sound, certain products, etc. For example:

In fact, this designation can be applied to almost everything that is traditionally flat - two-dimensional, but with the advent of new technology, it can be performed as three-dimensional.

In any phrase, this abbreviation means "voluminous".

Films

Previously, you can see the so-called stereo films, and even then not in all. And besides, this was not possible with all films.

Now this technology has become so widespread that it is even implemented in home TVs, and now the viewer has the opportunity to watch films with a three-dimensional image at home.

There are two technologies with which you can achieve the effect of presence. They have different technical features, but give a more or less similar result, that is, a high quality volumetric picture. These are active and passive imaging technologies, each of which has its own advantages and disadvantages.

Active 3D

This technology of "presence" can be realized in, it is quite complex and will work only with the use of special shutter glasses.

It is realized by dynamically changing different pictures.

When the glasses are worn on the viewer, at one moment he can see the image with only one eye, then only with the second (special dimmers in glasses are used).

But due to the fact that pictures and dimmers change very quickly, the viewer does not notice this blinking.

The implementation of this is quite complicated - you need not only glasses, but also a TV that supports such an imaging system.

At the same time, it is important that the glasses are accurately synchronized with the TV (most often - via bluetooth), and if this does not happen, then the picture quality will be very low.

An interesting feature of the technology is that the blinking and darkening of the lenses leads to a general subjective darkening of the picture in glasses, because the images in such films are made a little brighter.

It is possible, but not too pleasant to watch without glasses.

Passive 3D

This is a different technology that allows the use of very simple ones, which are known to everyone and have blue and red lenses.

This is the method used to implement a three-dimensional image in most cinemas, since such glasses are cheap, their cost in case of loss or damage can be included in the ticket price.

Of course, to realize this effect at home, you also need a TV that can work according to this scheme.

Important! You usually don't need to buy glasses separately. Televisions with the appropriate technology are equipped with several such glasses at once due to their low cost.

Here, the main burden falls not on the glasses, but on the TV. His screen, which divides the image line by line into two parts - blue and red.

Taking off your glasses, you may notice that the picture splits a little, stronger in the center, less noticeable at the vertical edges of the screen - this is the result of the filter in question.

With such a system, each eye sees only the picture that is intended for it - only even or only odd lines.

In this case, the lines intended for the other eye are blocked by the filter of the colored lens of the glasses. Thus, a volumetric image is built.

Comparative characteristics of technologies

Currently, equipment manufacturers have not come to an unambiguous opinion about which of the two technologies is more optimal and better meets the needs of the consumer, therefore, devices of both types are equally actively implemented.

Although the demand for a passive volumetric image is higher due to the cheaper cost of equipment with not too much reduced image quality.

The table below summarizes the advantages and disadvantages of both technologies for comparison.

Table 1. Comparative characteristics active and passive 3D technologies

Active	Passive
Glasses are quite expensive, as is a TV with this technology.	In general, the technology is cheaper than with active volumetric imaging
It is not always convenient to watch TV with glasses
May not be suitable for some people with migraines
It is necessary to monitor the charge of the glasses, as they have their own power supply	Most often there are a lot of glasses in the kit, they are cheap, they perform only a mechanical function of the filter
High image quality	Slightly lower image quality
Complete eye safety according to experts, or the load is low enough
Blinking and changing the picture takes up, albeit minimal, time - in dynamic scenes this can be quite noticeable	High picture quality is provided only by TVs that are quite expensive.
Even though manufacturers try to optimize brightness, movies will still be slightly darker than the original.	You cannot watch a movie at close range - the minimum distance from the screen to the viewer to build a high-quality picture is 3 m.

Regardless of technology, color quality is important- if it is low, then you will not be able to evaluate the quality of the volumetric video.

Frequency is also of great importance, especially with active image building.

All of these factors significantly affect the price of equipment, often so much that the price line between devices with passive and active technology is almost completely erased.

Advice. It should be taken into account that the film must also be processed to be reproduced in a three-dimensional format. Although the amount of such content is gradually increasing, there is still not much of it at the moment. Especially one that is really high quality.

Graphics

3D graphics in games have a slightly different meaning. This refers to the possibility of movement in a more or less realistic location.

A significant difference is, for example, the ability to inspect buildings, structures and objects from different angles gradually, while in games with two-dimensional graphics, when turning, for example, behind a building, one picture abruptly changed to another.

This is not about the presence effect.- we are only talking about a beautiful picture that creates the feeling of a realistic game. Since this is just a picture, no glasses are required here, since they are technically implemented differently. The picture is built on the basis of volumetric computer models of all objects in the game, as well as locations.

At the same time, when the player "moves" around the location, the pictures dynamically replace one another, creating a corresponding effect.

A high refresh rate of the screen is important here - if it is low, the picture will freeze, the image will "jump", etc.

Compared to traditional 2D games, 3D games put a lot of strain on the hardware resources of the hardware.

In addition, when playing online, it is very important high speed Internet connection and high quality connection.