CN107147899B - CAVE display system and method adopting LED3D screen - Google Patents

Abstract

The invention discloses a CAVE display system and a display method using an LED 3D screen. The method includes the following steps: collecting the coordinate positions of infrared marking points on 3D glasses; using the coordinate positions to estimate the position of the user's eyes; The two sets of pictures displayed relative to the 3D glasses are obtained by position calculation; the two sets of pictures are displayed alternately on the LED 3D screen; the left and right lenses are switched on and off the 3D glasses, and the switching frequency is displayed alternately with the two sets of pictures to match the switching frequency. Through the technical solution of the present invention, different from the existing CAVE system, the virtual display space is suitable for environments with strong light, and can be practically applied in bright indoor environments and even outdoor environments; the virtual display space has high color saturation, and the display screen Seamless splicing, giving users a good viewing effect; long service life.

Description

A CAVE display system and method using LED 3D screen

technical field

The invention relates to the technical field of data display, in particular to a CAVE display system and method using an LED 3D screen.

Background technique

The CAVE system can be applied to any virtual simulation application field with immersion requirements. For example, virtual design and manufacturing, virtual demonstration, collaborative planning, etc., are widely used. In most of the existing CAVE systems, the walls of the virtual display space are usually composed of rear projection walls. In addition to rear projection, the display on the ground part can also be projected on the ground by placing a projector above the display space. With the development of technology, the technology of replacing projection display by LCD 3D splicing screen or large-size LCD 3D screen has also appeared. But still missing a way to use an LED 3D screen as a CAVE system display.

There are two common CAVE systems in the prior art.

(1) CAVE system based on rear projection wall

The virtual display space of the CAVE system is composed of more than 3 (including 3) hard rear projection walls. The system uses multi-channel visual synchronization technology to display the entire 3D scene content on the projection wall. The user stands in the virtual display space and wears 3D glasses for viewing the three-dimensional imaging of the shadow wall, where infrared markers are attached to the 3D glasses. Infrared cameras are respectively placed on the corners of the virtual display space. Since the position of the infrared markers on the 3D glasses is not far from the position of the user's human eyes, it can be ignored compared to the specifications of the entire system, so the system uses the infrared camera to obtain the position parameters of the infrared markers to obtain the position parameters of the user's human eyes. According to the obtained user's eye position parameters, the system adjusts the image of the shadow wall to match the current position of the user's viewing (for example, the image close to the shadow wall will be enlarged, and the image far away from the shadow wall will be zoomed out). And combined with the picture calibration system, the picture at the corner is calibrated, so that the displayed image will not be distorted.

(2) CAVE system based on LCD 3D splicing screen or large-size LCD screen

The technical principle and technology (1) are basically the same, but the virtual display space is replaced by a rear projection wall with an LCD 3D splicing screen or a large-size LCD screen (except the ground screen), and is changed to display matching rendering channels and splicing processors .

However, the CAVE system in the prior art has the following disadvantages:

In technology (1), the virtual display CAVE system composed of a rear projection wall needs to be seen clearly in a dark environment, and has high requirements for ambient light. And the color saturation of the display screen is not high, and the viewing effect is not good. Projector life is short.

In technology (2), the CAVE system based on LCD 3D splicing screen or large-size LCD screen does not require high requirements for ambient light and has higher color saturation than rear projection walls, but long-term use will cause Inter-unit luminance and color falloff are inconsistent and irreversible. In addition, there are physical seams between the LCD screens, which affect the viewing effect. Large-size LCD screens also have the problem of difficult transportation.

With the improvement of display manufacturing technology, LED 3D display has appeared. The LED 3D display is self-luminous and is not limited by ambient light; the display screen has high color saturation, seamless splicing between displays, and long service life. If it can be applied to the CAVE system, it can greatly reduce the limitations of various terminal displays in the existing CAVE system.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides a CAVE system display method using an LED 3D screen, the method comprising the following steps:

1) Collect the coordinate positions of the infrared markers on the 3D glasses;

2) using the coordinate position to estimate the position of the user's eyes;

3) obtaining two sets of pictures displayed relative to the 3D glasses according to the position calculation;

4) Display the two groups of pictures alternately on the LED 3D screen;

5) The left and right lenses are switched on and off on the 3D glasses, and the switching frequency is matched with the switching frequency of the alternate display of the two sets of pictures, so that the user can experience an immersive stereoscopic vision virtual environment.

According to an embodiment of the present invention, preferably, in the step 2), the position of the user's eyes is sent to the multi-channel control server.

According to an embodiment of the present invention, preferably, in the step 4), the multi-channel control server generates the picture control signals of the four LED 3D screens according to the positions of the eyes of the user, and converts the picture control signals of the four LED 3D screens into the picture control signals of the four LED 3D screens. They are respectively sent to the four channel rendering servers, so as to display the calibrated two groups of pictures on the four LED 3D screens continuously and alternately.

According to an embodiment of the present invention, preferably, in step 5), the switching of the left and right lenses of the 3D glasses is specifically: the left eye screen appears, the left eye lens of the 3D glasses is turned on, and the right eye lens is turned off ; The right eye screen appears, the right lens of the 3D glasses is opened, and the left lens is closed.

According to an embodiment of the present invention, preferably, an IR transmitter receives the synchronization signal sent by the multi-channel control server, and transmits an infrared signal according to the picture synchronization signal, and the 3D glasses control the 3D glasses according to the infrared signal. The switching frequency of the left and right lenses of the glasses.

According to the embodiment of the present invention, preferably, the pictures displayed on the LED 3D screen are two sets of pictures obtained by shooting existing materials with two virtual cameras in the virtual environment of the CAVE system, simulating the left and right eyes of a human. and composition.

In order to solve the above technical problems, the present invention provides a CAVE display system using an LED 3D display screen. The system includes: 3D glasses, an IR transmitter, a multi-channel control server, a multi-channel rendering server, and a plurality of LED 3D display screens. , network switches, motion capture computers and infrared tracking systems;

The infrared tracking system tracks and obtains the coordinate position of the 3D glasses, and sends it to the network switch;

The motion capture computer obtains the coordinate position through the network switch, and obtains the position parameters of the user's eyes;

transmitting the location parameter to the multi-channel control server through the network switch;

The multi-channel control server generates picture control signals according to the received position parameters, and sends them to the multiple channel rendering servers respectively;

According to the control of the multiple channel rendering servers, the calibrated two groups of picture images are displayed on the multiple LED 3D display screens continuously and alternately;

Receive the synchronization signal sent by the multi-channel control server through the wireless transmitter, and transmit an infrared signal according to the picture synchronization signal, and the 3D glasses control the switching frequency of the left and right lenses of the 3D glasses according to the infrared signal, so that the Users experience an immersive stereoscopic virtual environment.

According to an embodiment of the present invention, preferably, the wireless transmitter is an IR transmitter.

According to an embodiment of the present invention, preferably, the 3D glasses are attached with two infrared marking points, corresponding to the eyes of the user, and the infrared tracking system obtains the coordinate position of the 3D glasses by tracking the infrared marking points on the 3D glasses, thereby Determine the position of the user's eyes.

In order to solve the above technical problems, the present invention provides a computer storage medium, which includes computer program instructions, and when the computer program instructions are executed, one of the above methods is performed.

The following technical effects have been achieved through the technical scheme of the present invention:

The present invention is different from the existing CAVE system, the virtual display space is suitable for the environment with strong light, and can be practically applied in the bright indoor environment, even the outdoor environment; Give users a good viewing effect; long service life.

Description of drawings

Fig. 1 is the structure diagram of the existing system of the present invention

Fig. 2 is the control flow chart of the present invention

Detailed ways

<System Architecture of the Present Invention>

3D glasses mainly achieve 3D effect by increasing the fast refresh rate of the picture (usually reaching 120Hz), which belongs to active 3D technology, also known as time division shading technology or liquid crystal time division technology. When a 3D signal is input to a display device (such as a monitor, projector, etc.), the image is generated alternately between left and right frames in a frame sequence format, and these frame signals are transmitted wirelessly through infrared transmitters, Bluetooth, etc., responsible for the received 3D The glasses are refreshed to realize the corresponding image for the left and right eyes, and maintain the same number of frames as the 2D video. The audience's two eyes see different pictures that are switched quickly, and an illusion is generated in the brain (the camera cannot capture the effect), A stereoscopic image can be viewed.

As shown in Figure 1, the virtual display space of the present invention is composed of four LED 3D display screens. The LED 3D display screen has the following characteristics: self-illumination, not restricted by ambient light; high color saturation of the display screen, seamless splicing between display screens, long lasting. A plurality of infrared cameras are arranged in the space corners of the LED 3D display screen; the number of cameras can range from at least three to more, depending on specific needs, and preferably, the number of cameras is eight. There are several infrared markers attached to the 3D glasses. Each pair of 3D glasses has left and right lenses, and the 3D glasses can respectively open and close the left and right 3D glasses lenses according to the received external signals, thereby realizing the alternate switching of the left and right lenses. In addition, four independent 3D channel rendering servers, multi-channel control servers, IR transmitters, motion capture computers and IR tracking systems, and network switches are required. The multi-channel control server is used to receive the position information of the user's eyes, and according to the position information, generate a picture control signal for controlling the four LED 3D display screens, and send the four picture control signals to the four-channel rendering server, In order to control the display of the four LED 3D display screens respectively. The IR transmitter is placed above the display space formed by the LED 3D display screen, is connected to the multi-channel control server, and receives the synchronization signal sent by the multi-channel control server. The IR transmitter receives the synchronization signal sent by the multi-channel control server, transmits an infrared signal according to the synchronization signal, and the 3D glasses control the switching frequency of the left and right lenses of the 3D glasses according to the infrared signal sent by the IR transmitter to match the frequency of the left and right lenses of the 3D glasses. The frequency of the screen images displayed alternately on the LED 3D display screen is consistent. It should be noted that the IR transmitter only belongs to a preferred embodiment. In practical applications, a signal transmitter of Bluetooth and high-frequency wireless signal communication can be used to wirelessly communicate with the 3D glasses to control the left and right of the 3D glasses. The frequency at which the mirror switch switches.

The motion capture computer obtains the position parameters of the infrared markers on the 3D glasses obtained by multiple infrared cameras (preferably eight) through the network switch, thereby indirectly obtaining the position parameters of the user's eyes. Set two markers at fixed distances on the frame of each 3D glasses, such as infrared LEDs. In the image obtained by the infrared camera, the infrared LED is the brightest point in most cases, and the position of the LED can be separated from the background by taking an appropriate threshold. The obtained position of the LED in the image reflects the user's horizontal angle and height relative to the camera, while the distance between the two LEDs reflects the user's distance from the camera. In this way, it is equivalent to obtain the user coordinates in the cylindrical coordinate system with the camera as the origin. Combined with the camera's own position coordinates, after a simple coordinate system transformation, the absolute coordinates of the user can be obtained. Due to the limited viewing angle, a single infrared camera cannot complete the task of 360° position capture, and several cameras can be used to stitch the field of view. A ring-belt camera can also be used, and one can achieve the task of 360° position capture, and the principle is the same as that of an infrared camera. Using the MotiveTracker in the computer, the position parameter information of the user's eyes is transmitted to the four-channel rendering server and the multi-channel control server through the switch. The multi-channel control server and the motion capture computer can be integrated in the same computer, or can be implemented by different computers respectively.

The picture displayed on the LED 3D screen is actually composed of two sets of pictures obtained by shooting the existing material with the left and right eyes of two virtual cameras in the virtual environment of the CAVE system. The CAVE system uses a multi-camera infrared positioning system to read the position parameters of the user's eyes by shooting infrared markers attached to the 3D glasses to calculate the position parameters of the two cameras in the virtual environment in the system (the two virtual cameras simulate the 3D glasses). position of the left and right mirrors), thereby obtaining images for two sets of display spaces displayed on the four LED 3D display screens respectively. Each 3D glasses has two markers at a fixed distance for the infrared tracking system to capture the position. The CAVE system then adjusts the image in the display space to match the current position the user is viewing according to the change in the position of the user's eyes (for example, the screen closer to the display will be enlarged, and the screen farther away will be reduced). And combined with the picture calibration system, the picture at the corner is calibrated, so that the display space image will not be distorted. The display space image is output and displayed by four independent 3D rendering services. The CAVE system displays the calibrated two sets of images continuously and alternately on the LED 3D display. At the same time, the 3D glasses switch between the left and right lenses according to the continuously alternately displayed screen images: the left eye screen appears, the left eye lens of the 3D glasses is opened, and the right lens is closed; the right eye screen appears, the right eye lens of the 3D glasses is opened, The left eye lens is closed. In order to synchronize the switching of the left and right eye images with the switching of the 3D glasses, the IR transmitter is placed above the display space, connected to the multi-channel control server, and used in conjunction with the 3D glasses.

Each lens of 3D glasses contains a liquid crystal layer that can turn black (light transmittance decreases) when a certain voltage is applied. On the contrary, it is similar to ordinary lenses without additional voltage. Since each frame of 3D image contains left and right pictures taken from different angles, the audience can only see when the left picture corresponds to the left lens (no fixed voltage is loaded on the lens) and the right picture corresponds to the right lens. 3D images.

In addition, the 3D glasses should have an ultra-high-speed frame rate to match the frame rate of high-speed projectors. At lower frequencies, such as several hundred Hz, it can be achieved by ferroelectric liquid crystals. If there are many users, it can be achieved by two ferroelectric Liquid crystal panels, in a cascaded manner, realize high-speed modulation. In this case, only when the front and rear liquid crystal panels are in the open state, the spectacle lenses are in the open state, and as long as one liquid crystal panel is in the closed state, the entire lens is in the closed state. If the time difference between the opening and closing of the liquid crystal panel is set to be small, a fast switching speed can be obtained.

A synchronization signal is required to control the alternation of the left and right lenses and the alternation of the left and right images to be consistent. Typically, infrared is used to transmit this synchronization signal. However, due to unfavorable factors such as being susceptible to fluorescent light interference and limited communication range, 3D shutter glasses using Bluetooth and high-frequency wireless signal communication have also been developed. Under the control of the synchronization signal, the voltage loaded on the left and right lenses changes alternately, and then the two images are combined by the brain to achieve a 3D visual effect.

The principle of 3D technology is based on the refresh time of the human eye to the image frequency, so by increasing the fast refresh rate of the picture (usually to 120Hz), the fast refresh rate of 60Hz for the left eye and the right eye will make people not to the image. Produces a jittery feeling, and maintains the same frame rate as 2D video.

It is mainly realized by liquid crystal glasses. Its glasses are essentially two LCD screens that can be controlled on/off respectively. The liquid crystal layer in the glasses has two states of black and white, which is usually displayed as white or transparent. It turns black when powered on. Accurate synchronization between the 3D glasses and the screen is achieved through the IR transmitter. The left and right eye pictures will be alternately played on the display screen. When the left picture is played, the left eyeglasses are turned on and the right eyeglasses are turned off. The left eye of the audience sees the picture that the left eye needs to see, but the right eye sees nothing. When playing the right-eye picture, the right eye sees the right picture, but the left eye cannot see the picture, so that the left and right eyes can see the left and right pictures respectively, so as to realize the 3D stereo effect. This process alternates at least 120 times per second, so that the human eye can enjoy a coherent and non-flickering 3D picture, so the active 3D display technology requires a screen refresh rate of at least 120Hz.

<The method flow of the present invention>

As shown in Figure 2, the present invention discloses a CAVE system display method using an LED 3D screen, the method comprising the following steps:

Step S1, collecting the coordinate positions of the infrared mark points on the 3D glasses.

The CAVE system uses a multi-camera infrared positioning system to read the position parameters of the user's eyes by shooting infrared markers attached to the 3D glasses to calculate the position parameters of the two cameras in the virtual environment in the system (the two virtual cameras simulate the 3D glasses). position of the left and right lenses).

Step S2, using the coordinate position to estimate the position of the user's eyes.

The motion capture computer obtains the position parameters of the infrared markers on the 3D glasses obtained by multiple infrared cameras (preferably eight) through the network switch, thereby indirectly obtaining the position parameters of the user's eyes. The system uses the MotiveTracker software in the computer, and the data is transmitted to the four-channel rendering server and the multi-channel control server through the switch.

In step S3, two sets of pictures displayed relative to the 3D glasses are obtained by calculating according to the position.

The CAVE system then adjusts the image in the display space to match the current position the user is viewing according to the change in the position of the user's eyes (for example, the screen closer to the display will be enlarged, and the screen farther away will be reduced). And combined with the picture calibration system, the picture at the corner is calibrated, so that the display space image will not be distorted. The display space image is output and displayed by four independent 3D rendering services.

Step S4, the two groups of pictures are alternately displayed on the LED 3D screen.

The multi-channel control server generates the picture control signals of the four LED 3D screens according to the position of the 3D glasses, and sends the picture control signals of the four LED 3D screens to the four channel rendering servers respectively, so as to realize the calibrated Two sets of pictures are continuously and alternately displayed on the four LED 3D screens.

Step S5 , switching the left and right lenses of the 3D glasses on/off, and the switching frequency is matched with the switching frequency of the two groups of pictures displayed alternately.

At the same time, the 3D glasses switch between the left and right lenses according to the continuously alternately displayed screen images: the left eye screen appears, the left eye lens of the 3D glasses is opened, and the right lens is closed; the right eye screen appears, the right eye lens of the 3D glasses is opened, The left eye lens is closed. In order to synchronize the switching of the left and right eye images with the switching of the 3D glasses lenses, it is also necessary to place the IR transmitter above the display space, and connect the multi-channel control server and the 3D glasses to work together.

When the left-eye and right-eye images are refreshed faster than 60Hz, the images of the left and right eyes are superimposed by the brain due to the persistence of vision of the human eye, resulting in a three-dimensional effect. The user will see a 3D image that does not flicker after calibration.

The picture displayed on the LED 3D screen is composed of two groups of pictures obtained by shooting existing materials with the left and right eyes of two virtual cameras in the virtual environment of the CAVE system.

<Specific embodiment of the present invention>

The present invention uses an LED 3D display screen with a dot pitch of P1.667, builds a front screen, left and right screens and a ground screen to form a four-sided display space, and the video splicer is MVC series. In order to render the images on the LED screen separately, four 3D channel rendering servers are also required, and the servers use the HP series. In addition, there is an infrared tracking system for the spatial positioning of the camera. This infrared tracking system contains eight infrared cameras and distributes them in the corners of the display space.

The user fixes the infrared markers on the 3D glasses. The 3D glasses are Active Glasses for TV. The motion capture computer obtains the position parameters of the infrared markers on the 3D glasses obtained by the eight infrared cameras through the network switch, thereby indirectly obtaining the position parameters of the user's eyes. The system uses the software Motive Tracker in the computer, and the data is transmitted to the four-dimensional channel rendering server and the multi-channel control server through the switch. The multi-channel control server matches the coordinate information of the viewer's eyes to the virtual environment, and obtains two sets of images for the left and right eyes, so that the display space image conforms to the real viewing angle of the human eye, and the entire display space image has no distortion.

The CAVE system displays the calibrated two sets of images continuously and alternately on the LED 3D screen. At the same time, the 3D glasses cooperate with this continuous alternating screen display to switch the left and right lenses. In order to synchronize the switching of the left and right eye images on the LED 3D screen with the switching of the left and right lenses of the 3D glasses, the IR transmitter needs to be placed above the display space, connected to the multi-channel control server, and used in conjunction with the 3D glasses.

When the left eye picture and right eye picture are each higher than 60Hz fast refresh. The user will see a 3D image that does not flicker after calibration.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be protected within the protection scope of the present invention.

Claims (5)

1. a CAVE system display method adopting LED3D screen, the method comprises the following steps: 1) Collect the coordinate positions of the infrared markers on the 3D glasses; 2) using the coordinate position to estimate the position of the user's eyes; 3) two groups of pictures displayed relative to the 3D glasses are obtained by calculating according to the positions of the two eyes of the user; 4) Display the two groups of pictures alternately on the LED3D screen; 5) Switching the left and right lenses of the 3D glasses, and the switching frequency is matched with the switching frequency of the alternate display of the two sets of pictures, so that the user can experience an immersive stereoscopic vision virtual environment; In the described step 2), the position information of the user's eyes is sent to the multi-channel control server; In the step 4), the multi-channel control server generates the picture control signals of the four LED3D screens according to the positions of the eyes of the user, and sends the picture control signals of the four LED3D screens to the four-channel rendering servers respectively, so as to realize the rendering of the four LED3D screens. The calibrated two groups of pictures are continuously and alternately displayed on the four LED3D screens; Among them, the synchronization signal sent by the multi-channel control server is received by the IR transmitter, and the infrared signal is transmitted according to the synchronization signal. The infrared signal controls the switching frequency of the left and right lenses of the 3D glasses; The picture displayed on the LED3D screen is composed of two groups of pictures obtained by shooting existing materials with the left and right eyes of two virtual cameras in the virtual environment of the CAVE system. 2. The method according to claim 1, wherein in step 5), the switching between the left and right lenses of the 3D glasses is specifically: the left eye screen appears, the left eye lens of the 3D glasses is turned on, and the right eye lens is turned on. Close; the right eye screen appears, the right lens of the 3D glasses is opened, and the left lens is closed. 3. A CAVE display system using an LED3D display screen, the system comprising: 3D glasses, an IR transmitter, a multi-channel control server, a multi-channel rendering server, a plurality of LED3D display screens, a network switch, a motion capture computer and infrared tracking system; The infrared tracking system tracks and obtains the coordinate position of the 3D glasses, and sends it to the network switch; The motion capture computer obtains the coordinate position through the network switch, and obtains the position parameters of the user's eyes; transmitting the location parameter to the multi-channel control server through the network switch; The multi-channel control server generates picture control signals according to the received position parameters, and sends them to the multiple channel rendering servers respectively; According to the control of the multiple channel rendering servers, the calibrated two sets of picture images are displayed on the multiple LED 3D display screens continuously and alternately respectively; Receive the synchronization signal sent by the multi-channel control server through the IR transmitter, and transmit an infrared signal according to the synchronization signal, and the 3D glasses control the switching frequency of the left and right lenses of the 3D glasses according to the infrared signal, The synchronization signal controls the alternation of the left and right lenses to be consistent with the alternation of the left and right images, so that the user can experience an immersive stereoscopic virtual environment; The picture displayed on the LED3D screen is composed of two groups of pictures obtained by shooting existing materials with the left and right eyes of two virtual cameras in the virtual environment of the CAVE display system. 4. The CAVE display system according to claim 3, wherein the 3D glasses are attached with two infrared marking points, corresponding to both eyes of the user, and the infrared tracking system obtains the coordinates of the 3D glasses by tracking the infrared marking points on the 3D glasses position to determine the position of the user's eyes. 5. A computer-readable storage medium comprising computer program instructions which, when executed, perform the method of one of the preceding claims 1-2.

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