Network nodes and programs

Abstract

To improve the transmission efficiency of three-dimensional object data.SOLUTION: A network node 20 includes: a stationary object data cache unit 26 that caches data of a stationary object; a viewport estimation unit 27 that generates a transmission object instruction that specifies a transmission object to be transmitted to a receiving device 30, and, if objects to be presented within the field of view of the receiving device 30 include the stationary object, adds the ID of the stationary object to the transmission object instruction only when the data of the stationary object has not been transmitted to the receiving device 30; and a packet filter unit 31 that outputs the data of the stationary object of object data received from a transmitting device 10 to the stationary object data cache unit 26 and also outputs the data of the transmission object specified by the transmission object instruction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a network node and a program.

Background Art

[0002] In recent years, due to the progress of AR (Augmented Reality) / VR (Virtual Reality) technology, AR / VR-compatible terminals and AR / VR content have begun to spread. AR / VR-compatible terminals include smartphones, tablet terminals, VR goggles, AR glasses, and the like. AR / VR handles 3D object data (3D model data) as content data.

[0003] Patent Document 1 discloses a technique for transmitting 3D object data to a receiving device (viewing terminal) in units of frames. According to this technique, since the packet has metadata that can identify the object to be transmitted, it is possible to separate static objects and dynamic objects and perform processing such that only static objects are transmitted at a low frame rate, and it is possible to reduce the amount of data transmitted to the receiving device without degrading the video quality.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique disclosed in Patent Document 1, since the data of static objects is transmitted periodically, there is room for improving the transmission efficiency.

[0006] In view of these circumstances, the object of the present invention is to provide a network node and a program capable of improving the transmission efficiency of 3D object data. [Means for solving the problem]

[0007] In one embodiment, a network node receives from a transmitting device 3D A network node that filters object data and transmits it to a receiving device, 3D A stationary object data cache unit that caches data of stationary objects, and a unit that transmits data to the receiving device. 3D Generate a transmission object instruction that specifies the transmission object, and present it within the field of view of the receiving device. 3D To the object 3D If a stationary object is included, 3D The transmission object instruction is only applicable when the data for a stationary object has not yet been transmitted to the receiving device. 3D A viewport estimation unit that adds the ID of a stationary object, and the receiving from the transmitting device 3D Among the object data, 3D The data of stationary objects is output to the stationary object data cache unit, and the data specified by the transmission object instruction is also output. 3D It includes a packet filter unit that outputs data of the transmitted object.

[0008] Furthermore, in one embodiment, the viewport estimation unit is made to present within the field of view of the receiving device. 3D Multiple objects that have not been sent to the receiving device 3D If stationary objects are included, the transmission object instruction will be sent at different timings for each of them. 3D You may add the ID of a stationary object.

[0009] Furthermore, in one embodiment, each receiving device 3D stillness objectIt includes a stationary object data transmission flag management unit that manages a flag indicating whether data has been transmitted, and the viewport estimation unit may determine whether the data of the 3D stationary object has been transmitted to the receiving device based on the flag.

[0010] Also, the program according to one embodiment causes a computer to function as the above network node.

Advantages of the Invention

[0011] According to the present invention, in the transmission of 3D object data, the amount of data transmitted to the receiving device can be reduced.

Brief Description of the Drawings

[0012] [Figure 1] It is a diagram showing a configuration example of a broadcast-type 3D space content transmission system according to one embodiment. [Figure 2] It is a block diagram showing a configuration example of a transmission data storage unit and a transmission device according to one embodiment. [Figure 3] It is a block diagram showing a configuration example of a network node according to one embodiment. [Figure 4] It is a flowchart showing the caching process to the stationary object data cache unit in the packet filter unit of the network node according to one embodiment. [Figure 5] It is a flowchart showing the object data output process to the packet transmission unit in the packet filter unit of the network node according to one embodiment. [Figure 6] It is a flowchart showing the process in the viewport estimation unit of the network node according to one embodiment. [Figure 7] It is a block diagram showing a configuration example of a receiving device according to one embodiment.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the "3D object" is simply referred to as an "object".

[0014] FIG. 1 is a diagram showing a configuration example of a broadcast-type 3D space content transmission system 1 according to an embodiment of the present invention. The 3D space content transmission system 1 shown in FIG. 1 includes a shooting / production system 50, a completed data storage unit 60, a data conversion device 70, a transmission data storage unit 80, a transmission device 10, a network node 20, and a reception device (viewing terminal) 30. In this embodiment, the data conversion device 70 and the transmission device 10 are separate devices, but the data conversion device 70 and the transmission device 10 may be integrated as one device.

[0015] The shooting / production system 50 produces 3D space content and outputs it as completed data to the completed data storage unit 60. The completed data is, for example, content data including one or more object data encoded by non-compression / lossless compression or lightweight compression with less degradation.

[0016] The data conversion device 70 converts the completed data input from the completed data storage unit 60 into transmission data and outputs it to the transmission data storage unit 80. The processing of the data conversion device 70 may be non-real-time or real-time offline processing, or real-time online processing. The transmission data is such that the object data is compressed by a compression method including non-reversible at a level where quality degradation when the user views the content is acceptable, and is converted into data suitable for distribution on the transmission path 90. At this time, object data compressed in a plurality of resolution patterns for one object can be generated. Also, both the completed data and the transmission data include information such as the configuration of the objects included in the content, the content title, and the names of each object as auxiliary information in the content data.

[0017] Furthermore, the data conversion device 70 refers to the auxiliary information of the completed data and generates content configuration metadata. The data conversion device 70 then includes the generated content configuration metadata in the output data and outputs it to the output data storage unit 80. The content configuration metadata may include data configuration information such as a list of objects and resolution patterns included in the 3D spatial content, as well as information such as the content title and the names of each object. The content configuration metadata is sometimes called a scene description.

[0018] The transmitting device 10 transmits objects, which are components of broadcast-type 3D spatial content, as object data to multiple network nodes 20 or receiving devices 30 via the transmission line 90.

[0019] The transmission line 90 includes communication transmission lines such as the global internet and closed networks operated by telecommunications carriers, as well as broadcast transmission lines such as terrestrial and satellite broadcasting.

[0020] Network nodes 20 are edge servers installed as equipment by telecommunications carriers or content providers, or home gateways installed by users in their homes. Bidirectional communication is generally possible between network nodes 20 and receiving devices 30, and multiple receiving devices 30 may be associated with a single network node 20. Since there can be countless receiving devices 30 that receive content via the transmission path 90, the content distributor (transmitter 10) does not necessarily know of the existence of all users (receiving devices 30).

[0021] (Transmission system) Figure 2 shows an example configuration of a transmission device 10 according to one embodiment of the present invention. The transmission data storage unit 80 stores content configuration metadata that describes various auxiliary information of the 3D content. The transmission data storage unit 80 also stores one or more object data.

[0022] The transmitting device 10 shown in Figure 2 comprises an ID determination unit 11, a transmission frame configuration unit 12, a metadata generation unit 13, a packet configuration unit 14, a packet transmission unit 15, and an object presentation location information generation unit 16.

[0023] The ID determination unit 11 refers to the content configuration metadata input from the transmission data storage unit 80 and determines an object ID to identify an object, and a packet ID to identify a packet for each resolution pattern of an object, for each object that is a component of broadcast-type 3D spatial content. The ID determination unit 11 then outputs ID information indicating the object ID and packet ID to the metadata generation unit 13 and the packet configuration unit 14. The object ID and packet ID are, for example, 16-bit unsigned integers.

[0024] It is also possible that object IDs for managing objects are pre-assigned in the content configuration metadata. The ID determination unit 11 may use the object ID described in the content configuration metadata as is if it conforms to the format for assignment to the packet header, or it may convert it to the format for assignment to the packet header using a predetermined conversion rule. Similarly, if there is an ID equivalent to the content configuration metadata (such as a resolution pattern ID) for the packet ID, it can be used. Furthermore, the ID determination unit 11 may automatically assign object IDs and packet IDs without relying on the content configuration metadata, or it may assign them according to separately provided settings, etc.

[0025] The object presentation position information generation unit 16 analyzes mainly the geometry of the object data input from the transmission data storage unit 80 and generates object presentation position information that indicates the representative presentation position of each object in world coordinates in three-dimensional space. Object presentation position information is generally sequential data that is updated at a frequency equal to or less than the frame rate of the content. The object presentation position information generation unit 16 then outputs the generated object presentation position information to the metadata generation unit 13.

[0026] Object presentation position information includes, for example, the average coordinates of all vertex coordinates of an object, the maximum value of a vertex coordinate, and bounding box information obtained using the maximum value of a vertex coordinate. Object presentation position information is dynamic information when the object moves in three-dimensional space. It is also possible that object presentation position information is included in the content configuration metadata beforehand. In that case, the object presentation position information generation unit 16 may use the object presentation position information included in the content configuration metadata without analyzing the object data. Figure 2 shows an example of obtaining object presentation position information from content configuration metadata.

[0027] The metadata generation unit 13 converts the content configuration metadata input from the transmission data storage unit 80 to conform to the format of the metadata for transmission, as needed. The metadata generation unit 13 also generates metadata that includes information linking the ID information (object ID and packet ID) input from the ID determination unit 11 with the object presentation location information input from the object presentation location information generation unit 16, as needed. The metadata generation unit 13 then outputs the generated metadata to the packet configuration unit 14.

[0028] The transmission frame configurator 12 configures a transmission frame for each object data. Each transmission frame has an independent data structure for each object. The transmission frame configurator 12 then outputs the configured transmission frame to the packet configurator 14. One transmission frame includes, for example, the geometry data and texture data of an object. Note that the unit of an object during transmission does not necessarily have to match the unit that is perceived as a single object. For example, in 3D spatial content, the main objects of the content may be transmitted as separate objects in transmission frames, but other background objects may be treated as a single object and transmitted in a transmission frame. Conversely, something that is perceived as a single object may be divided into multiple objects and transmitted during transmission. For example, an object such as a person may be divided into the head, which includes the face and is particularly likely to attract attention, and the other parts, and transmitted in transmission frames.

[0029] The metadata generation unit 13 converts the content configuration metadata input from the transmission data storage unit 80 to conform to the format of the metadata for transmission as needed. The metadata generation unit 13 then outputs the generated metadata to the packet configuration unit 14. The metadata is transmitted at regular intervals and is used by the receiving device 30 or network node 20 as auxiliary information to know the configuration of the objects in the 3D spatial content being received, and the object ID and packet ID of the data being transmitted.

[0030] The packet structuring unit 14 divides the transmission frame input from the transmission frame structuring unit 12 and the metadata input from the metadata generation unit 13 into packets to be used for transmission, and assigns an object ID and a packet ID to the packets according to the ID information input from the ID determination unit 11. Then, the packet structuring unit 14 outputs the generated packets to the packet transmission unit 15. In other words, the packet structuring unit 14 generates a packet of the transmission frame having the object ID and packet ID as header information, and a packet of metadata. Note that the packet ID is assigned to all packets. On the other hand, the object ID may be assigned to the header of all packets, or, if the transmission frame is divided into multiple packets, it may be assigned only to the header of the packet containing the beginning portion of the divided transmission frame.

[0031] The packet transmission unit 15 adds a destination address, destination port number, etc., to each packet input from the packet configuration unit 14 and transmits it to the transmission path 90.

[0032] (Network node) Next, a network node according to one embodiment of the present invention will be described with reference to Figure 3. Figure 3 is a diagram showing an example configuration of a network node 20 according to one embodiment. The network node 20 receives packets of 3D spatial content (object data and metadata) from the transmitting device 10 described above, filters them, and transmits them to the receiving device 30.

[0033] The network node 20 shown in Figure 3 comprises a packet filter unit 21, a metadata reconstruction unit 22, a metadata analysis unit 23, a packet configuration unit 24, a packet transmission unit 25, a stationary object data cache unit 26, a viewport estimation unit 27, and a stationary object data transmission flag management unit 28.

[0034] The stationary object data cache unit 26 caches stationary object data. "Stationary object data" refers to data of stationary objects.

[0035] The packet filter unit 21 outputs stationary object data from the object data received from the transmitting device 10 to the stationary object data cache unit 26, and outputs packets of data for the transmitted object specified by the transmitted object instruction input from the viewport estimation unit 27 to the packet transmission unit 25. In addition, the packet filter unit 21 outputs packets of metadata received from the transmitting device 10 to the metadata reconstruction unit 22.

[0036] A "transmission object instruction" is information that specifies the transmission object to be sent to the receiving device 30. The transmission object may be identified by its object ID. If the transmission object specified by the transmission object instruction includes a stationary object, the packet filter unit 21 retrieves the corresponding stationary object data from the stationary object data cache unit 26 and sends it to the packet transmission unit 25.

[0037] The caching process in the packet filter unit 21 to the stationary data cache unit 26 will be explained with reference to Figure 4. The packet filter unit 21 waits to receive object data from the transmitting device 10 (step S101), and when it receives object data (Yes in step S102), it determines whether the object data is stationary data or not (step S103). If the object data is stationary data (Yes in step S103) and the stationary data is not cached in the stationary data cache unit 26 (Yes in step S104), the packet filter unit 21 caches the stationary data in the stationary data cache unit 26.

[0038] In step S103, if information indicating whether or not the object data is stationary object data is added to the metadata, the packet filter unit 21 may make a determination based on that information. If stationary object data is transmitted periodically at a reduced transmission rate upstream of the network, the packet filter unit 21 may determine that object data transmitted at regular intervals from the upstream of the network is stationary object data.

[0039] The process of outputting object data to the packet transmission unit 25 in the packet filter unit 21 will be explained with reference to Figure 5. The packet filter unit 21 waits to receive a transmission object instruction from the viewport estimation unit 27 (step S201), and when it receives a transmission object instruction (Yes in step S202), it determines whether or not a stationary object is included in the transmission object to be sent to the packet transmission unit 25 (step S203). If a stationary object is included in the transmission object (Yes in step S203), it obtains stationary object data corresponding to the stationary object from the stationary object data cache unit 26 (step S204). Then, the packet filter unit 21 sends the data of the transmission object specified by the transmission object instruction to the packet transmission unit 25 (step S205).

[0040] Refer to Figure 3 again. The metadata reconstruction unit 22 reconstructs metadata from the metadata packets input from the packet filter unit 21. Specifically, the metadata reconstruction unit 22 reduces the content to include only the ID information of objects that the packet filter unit 21 has passed through, and also reduces object presentation location information that is not used by the receiving device 30. As a result, the amount of metadata information received by the receiving device 30 is reduced to the minimum necessary information, thereby reducing the processing load on the metadata analysis unit 33 of the receiving device 30.

[0041] The packet configuration unit 24 divides the metadata input from the metadata reconstruction unit 22 into packets to be used for transmission. The packet configuration unit 24 then outputs the metadata packets to the packet transmission unit 25.

[0042] The packet transmission unit 25 outputs the object data packets input from the packet filter unit 21 and the metadata packets input from the packet configuration unit 24 to the receiving device 30. The receiving device 30 caches the latest data received from the network node 20 for each object.

[0043] The metadata analysis unit 23 identifies the object ID and packet ID assigned to each object from the metadata input from the metadata reconstruction unit 22. The metadata analysis unit 23 then outputs ID information indicating the identified IDs to the packet filter unit 21 and the viewport estimation unit 27. In addition, the metadata analysis unit 23 identifies the object presentation position information from the metadata input from the metadata reconstruction unit 22 and outputs it to the viewport estimation unit 27.

[0044] The stationary object data transmission flag management unit 28 receives position and line-of-sight information from the receiving device 30 and manages a flag (hereinafter referred to as the "transmitted flag") for each receiving device 30 indicating whether or not each piece of stationary object data has been transmitted. When the transmitted flag is on (1), it means that the stationary object data has been transmitted, and when the transmitted flag is off (0), it means that the stationary object data has not been transmitted.

[0045] The stationary object data transmission flag management unit 28 starts flag management using the IP address and other information as identification information for the receiving device 30 when it first receives position and gaze direction information from the receiving device 30. Furthermore, if the stationary object data transmission flag management unit 28 is unable to receive position and gaze direction information from the receiving device 30 for a certain period of time, it determines that the user of the receiving device 30 has finished viewing and resets the flag management of the receiving device 30. The operation to turn on the transmitted flag is performed by the viewport estimation unit 27.

[0046] The viewport estimation unit 27 determines the objects to be presented within the field of view of the receiving device 30 based on the object presentation position information input from the metadata analysis unit 23 and the position and gaze direction information received from the receiving device 30, generates a transmission object instruction that specifies the transmission object to be sent to the receiving device 30, and outputs it to the packet filter unit 21. If the objects to be presented within the field of view of the receiving device 30 include a stationary object, the viewport estimation unit 27 does not add the ID of the stationary object to the transmission object instruction if the data for the stationary object has already been sent to the receiving device 30, and adds the ID of the stationary object to the transmission object instruction only if the data for the stationary object has not already been sent to the receiving device 30.

[0047] Specifically, the viewport estimation unit 27 checks whether the objects to be presented within the field of view of the receiving device 30 include stationary objects. If stationary objects are included, the viewport estimation unit 27 obtains a transmitted flag from the stationary object data transmission flag management unit 28 and determines whether the stationary object data, which is the data for the stationary object, has been transmitted to the receiving device 30. If the stationary object data has not been transmitted to the receiving device 30, the viewport estimation unit 27 stores the ID of the stationary object in the stationary object ID queue and turns on the stationary object transmitted flag of the receiving device 30 in order to transmit it to the receiving device 30.

[0048] Furthermore, if the object to be presented within the field of view of the receiving device 30 includes multiple stationary objects that have not yet been transmitted to the receiving device 30 (i.e., if there are multiple stationary object IDs in the stationary object ID queue), the viewport estimation unit 27 adds the IDs of the stationary objects to the transmitted object instruction one by one at different timings. This avoids transmitting multiple stationary object data to the receiving device 30 at the same frame timing, and makes it possible to transmit the stationary object data to the receiving device 30 with a frame delay.

[0049] The processing in the viewport estimation unit 27 will be explained with reference to Figure 6. The viewport estimation unit 27 waits to receive ID information and object presentation position information for one frame of all objects from the metadata analysis unit 23 (step S301). When it receives this information (Yes in step S302), it creates a transmission object instruction using the position and gaze direction information received from the receiving device 30 immediately before (step S303).

[0050] If the viewport estimation unit 27 determines that one or more stationary objects are included in the objects to be presented within the field of view of the receiving device 30 (Yes in step S304) and the stationary object data transmission flag management unit 28 has the stationary object transmission completed flag off for that stationary object (Yes in step S305), it stores the ID of the stationary object in the stationary object ID queue and turns on the stationary object transmission completed flag (step S306).

[0051] In step S306, the viewport estimation unit 27 may store one ID per frame in the stationary object ID queue, in ascending order of the IDs of the stationary objects. Alternatively, the viewport estimation unit 27 may store one ID per frame in the stationary object ID queue, in ascending order of the distance from the receiving device 30.

[0052] If the viewport estimation unit 27 finds that there is an ID for a stationary object in the stationary object ID queue (Yes in step S307), it retrieves the ID of one stationary object from the stationary object ID queue and adds it to the transmit object instruction (step S308), sends the transmit object instruction to the packet filter unit 21 (step S309), and returns the process to step S301.

[0053] In this way, the network node 20 caches stationary object data and transmits the stationary object data only once for each stationary object when it enters the field of view of the receiving device 30. Therefore, according to the present invention, it is possible to reduce the amount of data transmitted to the receiving device 30 when transmitting 3D object data.

[0054] Furthermore, conventional network nodes transmit multiple stationary objects at the same frame timing, which can result in a momentarily large amount of data being transmitted in a particular frame. In contrast, the network node 20 according to the present invention transmits the data for each stationary object at different frame timings when multiple stationary objects enter the field of view of the receiving device 30 simultaneously. Therefore, according to the present invention, it is possible to reduce the maximum bitrate in the transmission of 3D object data.

[0055] (Receiving device) Next, a receiving device 30 according to one embodiment of the present invention will be described with reference to Figure 7. Figure 7 is a diagram showing an example of the configuration of a receiving device 30 according to one embodiment.

[0056] The receiving device 30 shown in Figure 7 comprises a packet filter unit 31, a transmission frame metadata reconstruction unit 32, a metadata analysis unit 33, a terminal information transmission unit 34, a sensor 35, a camera 36, ​​a self-position / line of sight estimation unit 37, an object rendering unit 38, an AR synthesis unit 39, and a display unit 40.

[0057] The receiving device 30 is a viewing terminal that receives content data via the network node 20 and allows users to view 3D spatial content using augmented reality (AR).

[0058] The packet filter unit 31 receives packets that have already been filtered to contain only the necessary packets. Therefore, the receiving device 30 can reduce the processing load of discarding packets by the packet filter unit 31. The packet filter unit 31 separates multiple objects and metadata from the input packet flow.

[0059] The transmission frame / metadata reconstruction unit 32 reconstructs the transmission frame and metadata of an object from the packets input from the packet filter unit 31. The transmission frame / metadata reconstruction unit 32 then outputs the transmission frame to the object rendering unit 38 and the metadata to the metadata analysis unit 33.

[0060] The metadata analysis unit 33 identifies object presentation location information and the object ID and packet ID assigned to each object from the metadata input from the transmission frame metadata reconstruction unit 32. The metadata analysis unit 33 then outputs ID information indicating the identified IDs to the packet filter unit 31.

[0061] Sensor 35 includes various sensors such as an accelerometer and a gyroscope mounted on the receiving device 30, and outputs the detected sensor information to the self-position / line of sight estimation unit 37.

[0062] Camera 36 outputs the captured camera image to the self-position / line of sight estimation unit 37 and the AR synthesis unit 39.

[0063] The self-position / line of sight estimation unit 37 uses sensor information input from sensor 35 and camera images input from camera 36 to estimate the self-position of the receiving device 30 and the direction the camera 36 is facing, and generates position / line of sight information indicating the self-position of the receiving device 30 and the direction the camera 36 is facing. The self-position / line of sight estimation unit 37 then outputs the generated position / line of sight information to the object rendering unit 38.

[0064] The object rendering unit 38 receives the transmission frame from the transmission frame / metadata reconstruction unit 32 and performs rendering according to the self-position and gaze direction indicated by the position / gaze direction information received from the self-position / gaze direction estimation unit 37 to generate a rendered image of the object. The object rendering unit 38 then outputs the generated rendered image to the AR synthesis unit 39.

[0065] The AR synthesis unit 39 combines the rendered image of the object input from the object rendering unit 38 with the camera image input from the camera 36 to generate a composite image. The AR synthesis unit 39 then outputs the generated composite image to the display unit 40.

[0066] The display unit 40 is a display such as a liquid crystal display or an organic EL display, and displays the composite image input from the AR synthesis unit 39. In receiving terminals where the display unit 40 is a retinal projection display or a transparent display, such as see-through type AR glasses that allow the background to be seen through, the display unit 40 may display only the rendered image without performing the synthesis of the rendered image and the camera image in the AR synthesis unit 39.

[0067] The terminal information transmission unit 34 transmits the position and line of sight information of the receiving device 30 to the network node 20.

[0068] <Program> To enable the above-mentioned transmitting device 10, network node 20, or receiving device 30 to function, it is also possible to use a computer capable of executing program instructions. The computer can store a program in its memory that describes the processing content for realizing the functions of the transmitting device 10, network node 20, or receiving device 30, and this can be realized by having the computer's processor read and execute this program. At least a part of these processing contents may be realized by hardware. Here, the program instructions may be program code, code segments, etc., for executing the necessary tasks. The processor may be a CPU, GPU, DSP, ASIC (Application Specific Integrated Circuit), etc.

[0069] Furthermore, this program may be recorded on a computer-readable recording medium. Using such a recording medium, the program can be installed on a computer. Here, the recording medium on which the program is recorded may be a non-transient recording medium. A non-transient recording medium is not particularly limited, but may be a CD-ROM, DVD-ROM, or similar recording medium. This program can also be provided by download over a network.

[0070] Although the embodiments described above are representative examples, it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited by the embodiments described above, and various modifications and changes are possible without departing from the scope of the claims. For example, it is possible to combine multiple component blocks described in the embodiments into one, or to divide one into multiple components. [Explanation of symbols]

[0071] 1. Three-dimensional spatial content transmission system 10 Transmitter 11 ID determination section 12 Transmission frame configuration section 13 Metadata Generation Unit 14. Packet Configuration Section 15. Packet transmission section 16. Object presentation position information generation unit 20 network nodes 21 Packet Filter Section 22 Metadata Reconstruction Unit 23 Metadata Analysis Department 24 Packet Configuration Section 25 Packet transmission section 26 Stationary object data cache section 27 Viewport Estimation Unit 28 Stationary Object Data Transmission Flag Management Unit 30 Receiving device 31 Packet Filtering Section 32 Transmission Frame Metadata Reconstruction Unit 33 Metadata Analysis Department 34 Terminal Information Transmission Unit 35 sensors 36 Cameras 37 Self-position / line-of-sight direction estimation unit 38 Object Rendering Section 39 AR synthesis section 40 Display section 50 Filming and Production Systems 60 Completed Data Storage Unit 70 Data conversion device 80 Data transmission storage unit 90 Transmission lines

Claims

1. A network node that filters 3D object data received from a transmitting device and transmits it to a receiving device, A stationary object data cache unit that caches data of 3D stationary objects, A viewport estimation unit generates a transmission object instruction that specifies a three-dimensional transmission object to be transmitted to the receiving device, and if the three-dimensional object to be presented within the field of view of the receiving device includes a three-dimensional stationary object, it adds the ID of the three-dimensional stationary object to the transmission object instruction only if the data of the three-dimensional stationary object has not already been transmitted to the receiving device. A packet filter unit outputs data of three-dimensional stationary objects from the three-dimensional object data received from the transmitting device to the stationary object data cache unit, and outputs data of three-dimensional transmission objects specified by the transmission object instruction. A network node equipped with the following features.

2. The network node according to claim 1, wherein the viewport estimation unit adds the IDs of the three-dimensional stationary objects to the transmitted object instruction at different timings, one by one, if the three-dimensional object to be presented within the field of view of the receiving device includes a plurality of three-dimensional stationary objects that have not been transmitted to the receiving device.

3. Each receiving device is equipped with a stationary object data transmission flag management unit that manages a flag indicating whether or not data for each three-dimensional stationary object has been transmitted. The network node according to claim 1 or 2, wherein the viewport estimation unit determines, based on the flag, whether or not the data of the three-dimensional stationary object has been transmitted to the receiving device.

4. A program for causing a computer to function as a network node as described in claim 1.

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