What is the principle of 3D effect of 3D technology blockbusters?

The scene we see with the naked eye is a three-dimensional image with layers and depths. Generally speaking, what we call 3D games or movies are not real 3D. Because the screen is originally 2D, and the movie is shot with a single-lens camera, even the animated movie made with 3D technology is flat when output to the display screen. We call this 3D "planar 3D". Let's do a simple experiment first. First, stretch out one of your fingers and stare at it, then close your right eye and open your left eye. Then open your right eye, close your left eye, and carefully observe whether the left and right eyes are different. This difference is called "parallax". The technology of stereoscopic 3D is to display this "parallax" continuously on the screen. Therefore, in order for the viewer to see the real three-dimensional, the scenery seen by each eye must be slightly different from that seen by the other eye. In fact, this difference makes our eyes have a sense of depth when judging things, that is, the z axis of real 3D space. Let's do an experiment. First, we close one eye, pick up two pencils and try to connect them. We will find it difficult to do it, because one eye can't judge the sense of depth and can't determine the distance between two pens. At this time, if you open your eyes, you will find it very easy to do so, because you can judge the depth by looking at things from different positions of your eyes. From the above text, we basically know how the real 3D is formed. To put it simply, the objects we see with our naked eyes are different because of their different positions. Therefore, in order to experience the real 3D image, we must simulate this environment, that is, let our glasses see different things with their left and right eyes. How to realize such a visual environment? The current methods are: 1, going to the cinema to watch 3D movies. His principle is that in the process of film making, a special dual-lens (multi-lens) camera is used to shoot the film, each lens records the image of our naked eyes, and then the left and right images are projected onto the screen at the same time with a special dual projector, so that the image we see is a group of images with two overlapping images. Of course, this is not enough. At this time, we have to wear a special "polarizer". His function is to use the polarization principle of polarizer to make two sets of images overlapped on the screen get a set of images, so that the left and right eyes can see different sets of images, and then we can experience the real 3D image. At present, some large cinemas and science museums offer this kind of IMAX experience, so you can buy tickets to go to the cinema to experience it. 2. Use 3D stereoscopic LCD glasses. 3D LCD glasses are usually used in computers. You can play real 3D games and watch 3D movies through these glasses. The principle is to divide the original 3D game into two groups of images from different angles through software, and see different images through 3D LCD glasses. The LCD glasses are connected to the computer (there are also wireless products) by wires, and the computer controls the opening and closing of the lens of the LCD glasses through software to get different pictures of each eye, and the pictures are specially processed. For example, first open the LCD glasses in the left eye and close the lens in the right eye (in fact, it turns dark). At this time, the picture seen by the left eye is displayed on the screen, and then the lens of the right eye is opened, and the contents seen by the eyes are displayed at the same time, so that the left and right lenses are opened and closed alternately. Of course, this process is very fast. We can't feel the opening and closing of LCD glasses with naked eyes, but our left and right eyes can see different pictures, thus seeing the stereoscopic effect. This may be a good way to watch 3D movies or games at home, but it also has disadvantages. First of all, LCD glasses turn off the left and right lenses alternately, which will inevitably lead to flicker and instability of the picture. In addition, the requirements for the display are very high, because two pictures need to be displayed at the same time for the pictures watched alternately by the left and right eyes, so the screen refresh rate is twice as high as usual. That is to say, if we usually use the screen refresh rate of 80Hz, the display should reach the refresh rate of 160Hz when using LCD stereoscopic glasses. Obviously, this requirement is too harsh for the monitor. Even if the minimum required frequency is 50Hz, the screen should reach the frequency of 100Hz, which looks just right. But this flicker will be very serious, and it will also do great harm to the eyes. Another problem is that LCD glasses have great limitations, which can only be realized by computer controlling the cooperation between lenses and monitors. However, if your computer is an LCD screen, you have to give it up and need a special film source. Moreover, LCD glasses can not be used in DVD players (VCD or DVD), LCD TVs, plasma TVs and projectors, because they need to cooperate with special display frequencies, which also hinders 3D stereoscopic LCD. 3. Use red and blue glasses. This way may be the lowest cost and the lowest threshold for watching stereoscopic movies at this stage. Simply put, it is to use "red and blue glasses" to separate the pictures seen by the left and right eyes. This kind of film will be colored in red and blue respectively in post-production, that is, the image seen by one eye is red and the image seen by the other eye is blue. When playing a movie, these two images with different color casts overlap. Wear special "red and blue glasses" when watching movies. One pair of glasses has red lenses, and the other pair of glasses has blue lenses, which are filtered in different colors. For example, the image seen through the red lens will filter out the red image in the movie, while the other eye will filter out the blue image through the blue lens, so that each eye can see different images and achieve the purpose of watching the three-dimensional movie. In this way, because no special playing equipment and special glasses are needed, the viewing cost is very low. We can all make our own red and blue glasses without being limited by the playing equipment. It can be realized in all picture devices such as traditional TV, projector and LCD TV, and we can also watch still images, so its application range is very wide, and it is also widely adopted by film companies when making 3D DVD discs. But its shortcomings are also obvious, because this method first changes the color of the image, and the color of the picture you see is very distorted. Secondly, because two eyes are forced to pass through lenses of different colors, it is more irritating to the eyes when watching movies, which is easy to cause eye fatigue. This method is also the worst of the above methods, and the image overlap will be more serious, because the red and blue lenses can not completely filter out all colors, and the effect is not ideal, but it is easy to realize and popularize.