JP2004078414A - Multi-screen display method by multiple display devices, and program and recording medium for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a high-speed multi-screen synchronous display while reducing the amount of transmitted data and network load. <P>SOLUTION: In this multi-screen display method, computers (PC) constituting a plurality of display devices is divided in a master PC and a slave PC, and procedure by each PC includes the following steps. 1. The master and slave are self-loaded with three-dimensional spatial data from a database shared by a network. 2. The master measures the lapse of time and distributes common time to the slave every prescribed time. 3. The master monitors the occurrence of an event and provides itself and the slave with a command corresponding to the event at the occurrence of the event. 4. The master and slave autonomously update three-dimensional space and visual point information to plot using the time data and loaded three-dimensional spatial data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a display system including a plurality of display devices connected to a network, in which a single three-dimensional spatial image generated by computer graphics (CG) is divided into a plurality of screens, and an image of each display device is divided. The present invention relates to a multi-screen display method for displaying with continuity spatially and temporally by a display unit.
[0002]
[Prior art]
In a display system including a plurality of display devices connected to a network, a single three-dimensional spatial image is divided into a plurality of screens, and when displaying images that are spatially and temporally continuous, each screen is It is desired to synchronize the movement of the object displayed on the screen (the case where the object moves autonomously and the case where the object moves as a result of the movement of the viewpoint). When a multi-screen display method responding to such a demand is to be realized by a conventional technique, the following is considered. Explaining with reference to the flowchart of FIG. 10, each display device configuring a display system for multi-screen display has a network-connected computer and an image display unit connected to the computer, and the computer Use one as the master and the other as the slave. 10A shows a procedure of processing operation common to the master and the slave, FIG. 10B shows a procedure of processing operation for each frame by the master, and FIG. 10C shows a processing procedure for each frame by the slave. The operation procedure will be described below.
[0003]
The outline of the processing operation is as follows.
1) As shown in FIG. 10 (a), when the master and the slave are activated and establish communication with each other, they respectively load the three-dimensional spatial data from the database shared by the network.
2) The master updates the three-dimensional space and the viewpoint information in response to events such as the passage of time and user operations, and notifies the slave of a difference (change) from the previous frame.
3) The slave updates the three-dimensional space and the viewpoint information using the notified difference.
4) The master and the slave draw the three-dimensional space and the viewpoint information using the updated three-dimensional space and the viewpoint information.
5) Repeat steps 2), 3) and 4) until the end.
[0004]
Updating the three-dimensional space refers to the following processing.
a) Change in arrangement information (movement, rotation, scale) of an object (hereinafter, simply referred to as an object) constituting a three-dimensional space.
b) Switching display / non-display of an object.
c) Deformation of the object.
Updating of viewpoint information indicates the following processing.
d) Changing the viewpoint position.
e) Change of line-of-sight direction.
[0005]
[Problems to be solved by the invention]
The above conventional method is a so-called “space sharing / difference notification type”. The biggest problem with this conventional method is that the amount of data transmitted as a difference is very large. In other words, in the worst case, such as when the object is deformed over the entire three-dimensional space (that is, the vertex coordinates change), the amount of transmitted data may reach several million bits, and the network load is reduced. Increase and fail to achieve a stable frame rate.
For this reason, in many cases, a certain limit is imposed on updating for each frame. For example, a) restricting the update to only the viewpoint information (assuming that the three-dimensional space does not change), b) restricting the update to the three-dimensional space to only the arrangement information of the object (confirming that the object is not deformed) Is assumed), and the like.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to divide a single three-dimensional spatial image into a plurality of screens in a display system including a plurality of display devices connected to a network. In a multi-screen display method that displays data continuously and temporally, the amount of transmission data from the master to the slave can be reduced and the network load can be reduced, and images that are completely synchronized at high speed can be displayed on each image display unit. Is to do so.
Another object is to provide a program suitable for realizing a multi-screen display method for solving the above-mentioned problem, and a recording medium on which the program is recorded.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, an invention according to claim 1 divides a single three-dimensional spatial image in a display system including a plurality of display devices connected to a network and divides the image into a moving image by an image display unit of each display device. In the multi-screen display method of displaying a computer, a computer (hereinafter, referred to as a PC) constituting each display device is divided into one master PC and other slave PCs, and the following steps are included in a processing procedure by each PC. It is characterized by including. That is,
i) loading the three-dimensional spatial data from the network-shared database by the master and the slave, respectively;
ii) A step in which the master measures the passage of time and distributes time data to the slave at predetermined time intervals.
iii) A step in which the master monitors whether an event has occurred due to a user operation or the like, and when the event occurs, gives a command corresponding to the event to itself and the slave.
iV) A step in which the master and the slave autonomously update the three-dimensional space and the viewpoint information using the Zenki time data and the loaded three-dimensional space data based on the command corresponding to the event, and perform drawing.
Here, the event is a change in an external condition such as a time, and information manually input by a user's operation of a keyboard or a mouse.
[0008]
The synchronization method according to the first aspect of the present invention can be referred to as a "space / time / event sharing type". When the master PC determines that an event has occurred, the master PC and the slave PCs execute the same processing at the same time at the same time in order to give a predetermined command corresponding to the event to itself and all the slave PCs. As a result, the master PC and the slave PC share an event that occurs at an arbitrary time in time and space with the three-dimensional space loaded into the memory from the database shared by the network, and are almost completely synchronized. The captured video can be displayed.
[0009]
In the display system according to the first aspect of the present invention, which comprises a plurality of display devices connected to a network and has a computer of one display device as a master and a computer of another display device as a slave. A master computer program for realizing a multi-screen display method of dividing a three-dimensional space image and displaying a moving image by an image display unit of each of the display devices,
i) loading three-dimensional spatial data from a network-shared database into itself;
ii) measuring the passage of time and distributing common time data to the slave every predetermined time;
iii) monitoring the occurrence of an event, and, when an event occurs, giving a predetermined command corresponding to the event to itself and the slave;
iv) The event, that is, a change in state due to elapsed time and / or based on a command corresponding to a user operation or the like, using the time data and the loaded three-dimensional space data to generate a three-dimensional space and a viewpoint. Autonomously updating information and performing drawing (claim 2).
[0010]
The slave computer program is
i) loading three-dimensional spatial data from the network shared database into itself;
ii) using the time data and the loaded three-dimensional space data to recognize a three-dimensional space based on the event, ie, a change in state due to elapsed time and / or based on a command corresponding to a user operation or the like; Autonomously updating the viewpoint information and performing drawing (claim 3).
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram schematically illustrating a configuration of a display system including a plurality of display devices connected to a network for implementing a multi-screen display method according to the present invention. FIG. 2 is a diagram illustrating functions of a master PC. 3 is a diagram showing the functions of the slave PC, FIG. 4 is a conceptual diagram illustrating the basic operation between the master and the slave, and FIG. 5 shows a process until an image in a three-dimensional space is displayed on each image display unit. 6 is a schematic diagram, FIG. 6 is a flowchart for explaining a processing operation common to the master and the slave, FIG. 7 is a flowchart for explaining the processing for each frame of the master and the slave, and FIG. 8 is a description of the processing contents of steps S14 and S23 in FIG. FIG. 9 is a front view of a display screen showing a display example of the master and slave image display units.
[0012]
FIG. 1 shows an example in which a display system DS is composed of three display devices SA connected to a network. In FIG. 1, PC1 to PC3 are computers constituting each display device, It has sections IN1 to IN3, operation control sections CPU1 to CPU3, storage sections M1 to M3, and image display sections D1 to D3.
[0013]
Each PC is loaded with software for loading three-dimensional space data executed at the time of startup, software for performing synchronization processing for each frame (hereinafter, referred to as synchronization processing software), and software for performing drawing processing. . As shown in FIG. 2, the master PC 1 includes a three-dimensional spatial data loading unit 11 and a drawing unit 12 which are common to the slave PCs 2 and 3, and an elapsed time measuring unit 13 as a configuration unit unique to the master PC 1. , Time data distribution means 14, event detection means 15, and command provision means 16.
[0014]
On the other hand, the slave PCs 2 and 3 have the same configuration. As shown in FIG. 3, in addition to the three-dimensional space data loading unit 17 and the drawing unit 18 that are common to the master PC 1, time data It has a receiving unit 19 and a command receiving unit 20.
[0015]
In FIG. 1, a DB is a database shared by three display devices over a network, and stores basic data (three-dimensional spatial data) for generating a single three-dimensional spatial image.
The three-dimensional space data includes object placement information (ie, position / rotation / scale), object data, key frame animation of the object placement information, initial viewpoint information, and key frame animation of the viewpoint position / view direction.
Further, the object data includes shape data (that is, an array of vertex coordinates of polygons forming the object), attribute data (that is, material of the object (surface characteristics such as color and gloss)), and texture (that is, texture). It consists of a surface design defined by two-dimensional image data) and a key frame animation of vertex coordinates.
[0016]
As shown in FIGS. 4A and 5, the three-dimensional space data loading means 11 and 17 load the three-dimensional space data stored in the database DB shared by the network and store the master PC1 and the slave PC2. , PC3 in the storage units M1, M2, M3, respectively. The master PC 1 constantly measures the elapsed time by using the basic clock by the elapsed time measuring means 13 and, by the time data distribution means 14, every predetermined time, for example, every 33 ms when the frame rate is 30 per second. As shown in (b), the master PC 1 distributes common time data to each of the slave PCs 2 and 3 to manage the time of the master PC 1 and the slave PCs 2 and 3 in a unified manner.
[0017]
The event detection unit 15 monitors whether an event has occurred by operating the input unit IN1 such as a keyboard, a joystick, or a mouse, or by the arrival of a set time. When detecting the occurrence of the event, the master PC 1 composes a predetermined command corresponding to the event, gives the command to the master PC 1 by the command providing means 16, and simultaneously distributes the command to all the slave PCs 2 and PC3. This command includes, for example, the following.
* Change of object placement information (movement / rotation / scale) * Display / non-display of object * Deformation of object * Start of various key frame animations Represents the value of the information at a relative time (key frame) with reference to (0 frame) in time series, and the value corresponding to the time between key frames is obtained by appropriately interpolating. The key frame animation includes a key frame animation of the arrangement information of the object, a key frame animation of the vertex coordinates of the object, and a key frame animation of the viewpoint position and the line of sight. In this specification, obtaining a value at a certain time t in the key frame animation is expressed as "evaluating the key frame animation at the time t".
[0018]
Therefore, after that, the processes are executed at the same time in the master PC 1 and the slave PCs 2 and 3 based on the common time data. As a result, the master PC1, the slave PC2, and the PC3 share an event that occurs at an arbitrary time in space, time, and space, and can perform almost perfectly synchronized drawing. Therefore, each display device can display an image almost completely synchronized with the image display units D1 to D3.
[0019]
In the method of the present invention, since the event information and the elapsed time information are transmitted from the master to the slave as described above, this method can be called an event / space / time sharing method. Therefore, in the current multi-screen display method, the amount of data to be transmitted tends to be enormous because a change in the three-dimensional space generated as a result of the occurrence of the event is transmitted. Since only time information is transmitted, the amount of transmission data is significantly smaller than the former. Furthermore, in the present invention, data transmission is not performed individually for each slave, but is performed using a communication technique generally called multicast (a communication method for transmitting the same data to a plurality of nodes). Do. Thus, even if the number of display devices increases, the load on the network does not change (except for the physical limitation of the network port), and the number of screens can be increased indefinitely.
[0020]
The command generated based on the event detection includes a command defined in advance by the synchronization processing software (embedded command) and a processing method defined by the user independently (callback function = a function for calling a registered procedure). ) Registered in the synchronization processing software (custom command). Synchronization processing software prepares a template so that a user can easily implement a custom command.
[0021]
Next, the operation of each PC will be described with reference to FIGS. 5 to 9.
When both the master PC 1 and the slave PCs 2 and 3 are activated and communication between them is established, first, as shown in FIG. 6, the common three-dimensional space data d is loaded from the database DB (step S1 in FIG. 6). That is, the common three-dimensional space data d is stored in the storage units M1 to M3 of each PC in FIG. When the loading is completed, the processing for each frame is executed in the master PC 1 and the slave PCs 2 and 3 in step S3 until the end. The contents of the processing for each frame are as shown in FIG.
[0022]
That is, in the master PC 1, as shown in FIG. 7A, an event such as a user operation is detected by the event detecting means 15 (S11), and the presence or absence of the event is determined (S12). (Y in S12) generates a predetermined command corresponding to the event, causes the master PC 1 to recognize the command, and gives it to the slave PCs 2 and 3 to notify the occurrence of the event (S13).
Then, the master PC 1 executes the command in step S14. To explain the details of step S14, as shown in FIG. 8, when the master PC 1 detects a command (S5), it determines whether or not the command is a built-in command (S6). In the case of Y), processing (basic processing such as viewpoint movement, object switching, or movement) implemented by the synchronization processing program is executed (S7), and thereafter, the processing proceeds to step S15 in FIG. Transition.
If it is determined in step S5 that the detected command is not a built-in command (N in S6), it is determined whether or not the command is a user-defined command (custom command) (S8). If the result is affirmative, the process registered by the user through the callback function is performed (S9), and thereafter, the process proceeds to step 15 in FIG. If the result of the determination in step S8 is negative, the command is determined to be an undefined command, error processing is performed (S10), and the routine proceeds to step 15 in FIG. 7A.
[0023]
Subsequently, it is determined whether or not the time for one frame has elapsed (S15). When it is determined that the time for one frame has elapsed (Y in S15), the master PC transmits the time information at that time to the slave. It distributes (time data distribution) to the PCs 2 and 3 (S16) and executes a process according to the passage of time (S17). Specifically, the evaluation of the key frame animation and the reflection of the value obtained as a result of the evaluation on the three-dimensional space / viewpoint information are performed. Here, the viewpoint information is a general term for information on the viewing frustum when drawing a three-dimensional space including a viewpoint position, a line-of-sight direction, and a viewing angle.
Then, the three-dimensional space and viewpoint information assigned to the master PC 1 are drawn (S18). In this case, the drawing range of the PC 1, that is, the object to be drawn is automatically determined by the parameters set in the PC 1 at the time of startup. For example, when the viewing angle is divided into three in the horizontal direction and the parameters are set so that the PC 1 is in charge of drawing at the center, d1 of the three-dimensional space data d in FIG. 5 is to be processed.
When the processing for each frame in the master PC 1 ends (Y in S2), in step S4, end processing such as release of various used resources is executed.
[0024]
On the other hand, in the slave PCs 2 and 3, as shown in FIG. 7B, first, in step S21, reception from the master PC 1, that is, event notification or time data distribution is awaited. Then, it is determined whether or not an event notification has been detected (S22). If an event notification has been detected, in step S23, a command is executed in the same manner as in step S14 by the master PC 1.
[0025]
Subsequently, it is determined whether or not the time data has been received from the master PC 1 (S24). If the time data has been received, a process corresponding to the lapse of time is executed in the same manner as the master PC 1 (S25). Since the processing according to the elapse of time is performed based on the time data received from the master PC 1, the drawing contents on each display device are completely synchronized. Thus, the three-dimensional space and the viewpoint information assigned to the slave PCs 2 and 3 are drawn. In the slave PCs 2 and 3 as well, the objects to be drawn are automatically determined by the parameters set in the respective PCs at the time of startup, as in the case of the master PC 1. For example, in the PC 2, among the three-dimensional space data d in FIG. d2 and d3 in the PC3 are the drawing targets. When the processing for each frame in each of the slave PCs 2 and 3 ends (Y in S2), in step S4, end processing such as release of various used resources is executed.
[0026]
FIG. 9 shows an example of display by the image display units D1 to D3 of three display devices in one display system. The image display units D1 to D3 in the upper part (Ta) display the (frame rate) at a certain time. Indicates the image (1/33 second if 30 frames per second), and the image display units D1 to D3 in the lower part (Tb) show the image (also 1/33 second) at a certain time after the lapse of a certain time. Is shown. These display contents are based on three-dimensional space data stored in the database DB.
a. Plains dotted with houses b. Celestial sphere with clouds scattered above the plain c. A group of cylindrical objects oscillating in the forest on a plain d. In the case of constituting a group of spherical objects orbiting above the plain, the three-dimensional spatial data is loaded into the master PC1, the slave PC2, and the PC3, respectively, stored in the storage units M1 to M3, and the viewing angle is set. The object is divided into three parts in the horizontal direction, and the master PC1 puts the object group d1 that fits in the field of view of the central part in the center image display unit D1, and the slave PC2 and PC3 puts the object groups d2 and d3 that fit in the field of view of the right and left parts. Are drawn on the right and left image display sections D2 and D3. Thus, the video is displayed on the three parallel image display units. In the example of FIG. 9, the swing of the columnar object group c and the orbital movement of the spherical object group d are displayed in complete synchronization between the image display units.
It goes without saying that the three-dimensional space data is not limited to the example of FIG. The same continuity and synchronization can be achieved not only when the plurality of image display units are arranged horizontally but also when they are arranged vertically.
[0027]
The maximum length of the command in the built-in command or the custom command is set to, for example, 512 bytes by the synchronization processing software so as not to increase the processing load. Also, since the data used for time distribution is about several tens of bytes, the transmission load on the network is significantly lower than that of the conventional type. Therefore, there is no need to limit the updating of the three-dimensional space and the viewpoint information. As a result, a high-speed multi-screen display application can be constructed.
[0028]
In the above embodiment, the number of display devices connected to the network is three, but the number of display devices connected can be an arbitrary number of two or more. In the above embodiment, the three-dimensional space data is loaded at the time of starting each PC. However, the present invention is not limited to this, and after the PC is started, the three-dimensional space data is loaded at an arbitrary timing during operation. Thereafter, processing for each frame may be performed.
[0029]
【The invention's effect】
As described above, according to the first aspect of the present invention, a single three-dimensional spatial image is divided into screens by a plurality of computers connected to a network, and each screen is displayed with spatial and temporal continuity. In doing so, each computer is divided into one master and the other slaves. The processing procedure by each computer includes a step of loading the three-dimensional spatial data shared by the network by the master and the slave, and the master includes: Monitoring the presence / absence of an event and providing a predetermined command corresponding to the event to itself and the slave when the event occurs; and measuring the elapsed time and distributing common time data to the slave every predetermined time. And the master and the slave recognize the occurrence of an event and / or a change in state due to elapsed time. 3D space and the viewpoint information autonomously updated each so and a step for drawing, enabled fast multi-screen display by remarkable reduction of the transmission load of the network.
[0030]
According to the second and third aspects, it is possible to provide a program suitable for realizing a multi-screen display method capable of high-speed multi-screen display by remarkably reducing the transmission load on the network.
[0031]
Further, according to the fourth and fifth aspects, a recording medium on which a program suitable for realizing a multi-screen display method capable of high-speed multi-screen display by remarkably reducing transmission load on a network is provided. can do.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a configuration of a display device system for implementing a multi-screen display method according to the present invention.
FIG. 2 is a table showing functions of a master PC.
FIG. 3 is a table showing functions of a slave PC.
FIG. 4 is a conceptual diagram illustrating a basic operation between a master PC and a slave PC.
FIG. 5 is a schematic diagram showing a process until an image in a three-dimensional space is displayed on each image display unit.
FIG. 6 is a flowchart illustrating a processing operation common to the master PC and the slave PC.
FIG. 7 is a flowchart for explaining processing for each frame of the slave PC.
FIG. 8 is a flowchart showing the contents of steps S14 and S23 in FIG. 7;
FIG. 9 is an exemplary front view showing a display example of an image display unit of a master PC and a slave PC.
FIG. 10 is a flowchart illustrating the operation of a conventional multi-screen display method.
[Explanation of symbols]
DS display system DA1 to DA3 display device PC1 master computer PC2, PC3 slave computer D1 to D3 image display unit M1 to M3 storage unit IN1 to IN3 input unit DB database

Claims (5)

In a multi-screen display method of dividing a single three-dimensional spatial image in a display system including a plurality of display devices connected to a network and displaying a moving image by an image display unit of each of the display devices,
(A) dividing the computer constituting each display device into one master and other slaves,
(B) The processing procedure by the master includes:
i) loading three-dimensional spatial data from a network-shared database into itself;
ii) measuring the passage of time and distributing common time data to the slave every predetermined time;
iii) monitoring whether an event has occurred and, when an event has occurred, giving a predetermined command corresponding to the event to itself and the slave;
iv) autonomously updating the three-dimensional space and viewpoint information using the time data and the loaded three-dimensional space data based on a command corresponding to the event, and performing drawing.
(C) The processing procedure by the slave includes:
i) loading three-dimensional spatial data from the network shared database into itself;
ii) autonomously updating the three-dimensional space and the viewpoint information using the time data distributed from the master and the loaded three-dimensional space data based on a command given from the master, and performing drawing. Including,
A multi-screen display method characterized by the following. In a display system including a plurality of display devices connected to a network and using one display device computer as a master and another display device computer as a slave, a single three-dimensional spatial image is divided into each of the above display devices. A multi-screen display method program for displaying a moving image by an image display unit of the device,
i) loading three-dimensional spatial data from a network-shared database into itself;
ii) measuring the passage of time and distributing common time data to the slave every predetermined time;
iii) monitoring whether an event has occurred and, when an event has occurred, giving a predetermined command corresponding to the event to itself and the slave;
iv) autonomously updating 3D space and viewpoint information using the time data and the loaded 3D space data based on the command, and performing drawing. In a display system including a plurality of display devices connected to a network and using one display device computer as a master and another display device computer as a slave, a single three-dimensional spatial image is divided into each of the above display devices. A multi-screen display method program for displaying a moving image by an image display unit of the device,
i) loading three-dimensional spatial data from the network shared database into itself;
ii) based on a command given from the master, autonomously updating the three-dimensional space and viewpoint information using the loaded time data distributed from the master and the loaded three-dimensional space data, and performing drawing. Program for slave computer including. A recording medium recording the master computer program according to claim 2. A recording medium recording the slave computer program according to claim 3.

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