Construction model viewpoint switching system, construction model viewpoint switching method, and program

Abstract

[Problem] To facilitate communication between users who are browsing the same construction model. [Solution] A construction model viewpoint switching system for switching viewpoints of users who are browsing three-dimensional construction model data in which a building is reproduced on a computer, in which the construction model viewpoint switching system: acquires three-dimensional construction model data; three-dimensionally outputs, to a plurality of users, the building based on the acquired three-dimensional construction model data; outputs a user identifier of each user browsing the building that has been output; acquires the position, the direction, or the angle of the viewpoint of each user browsing the building as a user viewpoint of each user; holds each of the acquired user viewpoints; receives a selection of a user identifier from a first user who is browsing the building that has been output; and switches the user viewpoint of the first user to a user viewpoint of the second user corresponding to the received user identifier on the basis of the received user identifier and each user viewpoint that is held.

Description

Construction model viewpoint switching system, construction model viewpoint switching method and program

[0001] The present invention relates to a technique that is effective in utilizing BIM (Building Information Modeling) three-dimensional models.

[0002] The construction industry utilizes virtual computer-generated construction models. One example of a construction model is the BIM 3D model. A BIM 3D model is a building database that adds attribute data, such as cost, finish, and management data, to a 3D digital model of a building created on a computer. This information can be used in all processes, from design and construction to maintenance and management. For example, Patent Document 1 discloses a technology for virtually placing electrical component objects when using BIM for equipment design. Patent Document 2 also discloses a technology for comparing the design data of a BIM model with the results of a conformance assessment of a building structure, thereby reducing the effort required for design revisions and human error.

[0003] JP 2024-14134 A JP 2023-138268 A

[0004] However, when multiple people operate a construction 3D model, it is difficult to grasp the camera angle or camera coordinates from which other users are viewing the construction 3D model, resulting in inefficiency when communicating while viewing the construction 3D model with each other. For example, if user X is looking at the front entrance of a building in the construction 3D model from north to south, and another user Y wants to view the same viewpoint as user X, user Y needs to ask user X which viewpoint user Y is viewing from and adjust his or her own viewpoint. However, because viewpoint adjustment involves multiple parameters, such as viewpoint position, direction, and angle, and involves 3D manipulation, it is difficult to easily switch between them. The technologies described in Patent Documents 1 and 2 were unable to solve these problems. Therefore, the present inventor focused on a mechanism that makes it easy to grasp the viewpoint from which other users are viewing the construction 3D model.

[0005] In consideration of these problems, the present invention aims to provide a construction model viewpoint switching system, a construction model viewpoint switching method, and a program that enable users to easily understand the camera angle and camera coordinates that others are using to view a construction model, thereby facilitating smooth communication between users viewing a common construction model.

[0006] The present invention provides a construction model viewpoint switching system that switches the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer, comprising: a three-dimensional construction model data acquisition unit that acquires the three-dimensional construction model data; a three-dimensional output unit that outputs a building based on the acquired three-dimensional construction model data to multiple users in three dimensions and outputs the user identifier of each user viewing the output building; a user viewpoint acquisition unit that acquires the position, direction, or angle of the viewpoint of each user viewing the building as the user viewpoint of each user; a storage unit that stores each of the acquired user viewpoints; a user identifier acceptance unit that accepts a selection of the user identifier from a first user viewing the output building; and a user viewpoint switching unit that switches the user viewpoint of the first user to the user viewpoint of a second user corresponding to the accepted user identifier based on the accepted user identifier and each of the held user viewpoints.

[0007] According to the present invention, it is possible to easily grasp the camera angle and camera coordinates that other users are using to view a construction model, thereby facilitating smooth communication between users viewing a common construction model.

[0008] Although the present invention is categorized as a system, the same effects and advantages can be obtained even when it is a method or a program.

[0009] According to the present invention, it is possible to facilitate communication between users viewing a common construction model.

[0010] 1 is a diagram illustrating an overview of the construction model viewpoint switching system 1. FIG. 2 is a diagram illustrating the functional configuration of the construction model viewpoint switching system 1. FIG. 3 is a diagram illustrating a flowchart of a building output process executed by a computer 10. FIG. 4 is a diagram illustrating a screen when an information terminal 3 displays a building. FIG. 5 is a diagram illustrating a flowchart of a user viewpoint acquisition process executed by a computer 10. FIG. 6 is a diagram illustrating a coordinate system when determining the position, direction, and angle of a user's viewpoint. FIG. 7 is a diagram illustrating a flowchart of a user viewpoint switching process executed by a computer 10. FIG. 8 is a diagram illustrating a screen when an information terminal 3a outputs the user viewpoint of a second user. FIG. 9 is a diagram illustrating a flowchart of a following process executed by a computer 10. FIG. 10 is a diagram illustrating a flowchart of a re-following process executed by a computer 10. FIG. 11 is a diagram illustrating a flowchart of a bookmark list sharing process executed by a computer 10. FIG. 12 is a diagram illustrating a flowchart of a bookmark icon sharing process executed by a computer 10. FIG. 13 is a diagram illustrating a flowchart of a release process executed by a computer 10.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of embodiments of the present invention will be given with reference to the accompanying drawings. In the following drawings, the same elements are designated by the same numbers or symbols throughout the description of the embodiments.

[0012] [Overview of Construction Model Viewpoint Switching System 1] Figure 1 is a schematic diagram for explaining an overview of the construction model viewpoint switching system 1. The components of the construction model viewpoint switching system 1 will be explained based on Figure 1. The construction model viewpoint switching system 1 is a system that switches the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer, and is made up of at least a computer 10 having a server function. In this embodiment, the construction model viewpoint switching system 1 includes, in addition to the computer 10, information terminals 3 used by each of multiple users viewing the three-dimensional construction model data (information terminal 3a used by a first user, information terminal 3b used by a second user, ..., information terminal 3n used by an nth user).

[0013] The information terminal 3 is a terminal device used by a user, and is, for example, a terminal device such as a mobile phone, a smartphone, a tablet terminal, a personal computer, or a laptop computer, or a wearable terminal such as a smart watch, smart glasses, or an HMD (Head Mounted Display). The information terminal 3 can be designed appropriately depending on the number of users.

[0014] The computer 10 has a server function and may be realized, for example, by a single computer, or may be realized by multiple computers, such as a cloud computer. In this specification, a cloud computer may refer to either a computer that uses any computer in a scalable manner to perform a specific function, or a computer that includes multiple functional modules to realize a system and uses the functions in any combination.

[0015] In addition, the construction model viewpoint switching system 1 may include external systems, other terminals and devices, etc. in addition to the information terminal 3 and computer 10 described above, and the number, types and functions thereof are not particularly limited and can be designed as appropriate.

[0016] An outline of the processing steps performed by the construction model viewpoint switching system 1 when switching the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer will be described.

[0017] The computer 10 acquires three-dimensional construction model data from the information terminal 3 (step S1).

[0018] The computer 10 outputs a building based on the acquired 3D construction model data to multiple users in three dimensions, and also outputs the user identifiers of each user viewing the output building (step S2). The computer 10 generates a 3D model based on the acquired 3D construction model data. The computer 10 places the user identifiers of each user, such as a list or iconized user identifiers, in a position near the generated 3D model, in a blank space, etc. The computer 10 outputs the 3D model with the user identifiers of each user placed to the information terminal 3 in three dimensions.

[0019] The computer 10 acquires the position, direction, or angle of the viewpoint of each user viewing the building as the user viewpoint of each user (step S3). The computer 10 acquires the parameters of the position, direction, or angle of the viewpoint of each user from the information terminal 3 through which each user is viewing the building as the user viewpoint of each user. The user viewpoint may be any one of the position, direction, or angle of the viewpoint of each user, a combination of a plurality of them, or all of them.

[0020] The computer 10 stores each of the acquired user viewpoints (step S4). The computer 10 stores each of the acquired user viewpoints in association with the user identifier of each user.

[0021] The computer 10 accepts the selection of a user identifier from the first user who is viewing the output building (step S5). The computer 10 accepts the selection of a user identifier from the first user via the information terminal 3a.

[0022] Based on the received user identifier and each user viewpoint stored, the computer 10 switches the user viewpoint of the first user to the user viewpoint of the second user corresponding to the received user identifier (step S6). The computer 10 references each parameter of the user viewpoint of the second user corresponding to the received user identifier among the user viewpoints stored, changes the user viewpoint of the first user to each parameter of the corresponding user viewpoint of the second user, and switches the user viewpoint of the first user to the user viewpoint of the second user. The computer 10 transmits the switched user viewpoint to the information terminal 3a. The information terminal 3a receives this switched user viewpoint and displays the building based on the switched user viewpoint.

[0023] The above is an overview of the construction model viewpoint switching system 1. The construction model viewpoint switching system 1 makes it possible to facilitate smooth communication between users viewing a common construction model.

[0024] [Device Configuration] Figure 2 is a block diagram showing the configuration of the construction model viewpoint switching system 1. The device configuration of the construction model viewpoint switching system 1 will be described with reference to Figure 2. The construction model viewpoint switching system 1 is a system for switching the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer, and is configured at least by a computer 10. In this embodiment, the construction model viewpoint switching system 1 is configured by an information terminal 3 in addition to the computer 10, as described above. The construction model viewpoint switching system 1 is a system in which the computer 10 is connected to multiple information terminals 3 via a network 8, such as a public line network, so as to be able to communicate data with them. Note that the construction model viewpoint switching system 1 may include external systems, other terminals, devices, etc. in addition to the information terminals 3 and the computer 10, and the number, types, and functions thereof can be designed as appropriate. The number of information terminals 3 can be designed as appropriate depending on the number of users.

[0025] The information terminal 3 is the above-mentioned terminal device used by a user who views the three-dimensional construction model data. There are multiple information terminals 3 in the construction model viewpoint switching system 1, such as information terminal 3a used by a first user (user identifier: "user A"), information terminal 3b used by a second user (user identifier: "user B"), information terminal 3c used by a third user (user identifier: "user C"), ..., information terminal 3n used by an nth user (user identifier: "user n"). In this embodiment, an example will be described in which there are three information terminals 3, information terminals 3a to 3c, but in Figure 2, information terminals 3a to 3c may be terminal devices having similar configurations, so information terminal 3 is shown as a representative. The information terminal 3 includes a terminal control unit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), etc., and includes a communication unit such as a device for enabling communication with other terminals, devices, etc. The information terminal 3 includes an input / output unit such as various devices for receiving predetermined inputs, inputting / outputting various data, etc.

[0026] The computer 10 has a server function and may be realized, for example, by a single computer or by multiple computers, such as a cloud computer. The computer 10 includes a control unit such as a CPU, GPU, RAM, ROM, etc., a communication unit such as a device for enabling communication with other terminals and devices, a 3D construction model data acquisition unit for acquiring 3D construction model data, a 3D output unit for outputting a building based on the acquired 3D construction model data to multiple users in 3D and outputting a user identifier of each user viewing the output building, a user viewpoint acquisition unit for acquiring the position, direction, or angle of the viewpoint of each user viewing the building as the user viewpoint of each user, and a user identifier acceptance unit for accepting a user identifier selection from a first user viewing the output building. The computer 10 includes a data storage unit such as a hard disk, semiconductor memory, recording medium, memory card, etc., as a memory unit, and a retention unit for retaining each acquired user viewpoint. The computer 10 includes, as a processing unit, various devices that perform various processes, a user viewpoint switching unit that switches the user viewpoint of a first user to the user viewpoint of a second user corresponding to the received user identifier based on the received user identifier and each user viewpoint held.

[0027] In the computer 10, the control unit loads a predetermined program and, in cooperation with the communication unit, realizes a 3D construction model data acquisition module, a 3D output module, a user viewpoint acquisition module, a user identifier reception module, a user viewpoint output module, a bookmark reception module, a list sharing module, a list selection reception module, an icon sharing module, an icon selection reception module, and a cancellation reception module. Furthermore, in the computer 10, the control unit loads a predetermined program and, in cooperation with the memory unit, realizes a retention module. Furthermore, in the computer 10, the control unit loads a predetermined program and, in cooperation with the processing unit, realizes a 3D model generation module, a viewpoint icon placement module, a viewpoint icon switching module, a user viewpoint switching module, an analysis module, a change determination module, a tracking module, a re-tracking module, a bookmark list generation module, a bookmark list switching module, a bookmark icon placement module, and a bookmark icon switching module.

[0028] Below, we will explain each process executed by the construction model viewpoint switching system 1, along with the process executed by each of the above-mentioned modules. In this specification, each module may execute its processing content as its own function, or may execute it via a predetermined application.

[0029] [Building Output Processing Executed by Computer 10] The building output processing executed by the computer 10 will be described with reference to Fig. 3. This figure is a flowchart of the building output processing executed by the computer 10. The building output processing includes details of a 3D construction model data acquisition processing (step S1) for acquiring 3D construction model data, and a 3D output processing (step S2) for outputting a building based on the acquired 3D construction model data in 3D to multiple users and outputting the user identifiers of each user who views the output building.

[0030] The three-dimensional construction model data acquisition module acquires three-dimensional construction model data (step S10). The three-dimensional construction model data is, for example, BIM data. The three-dimensional construction model data acquisition module acquires the three-dimensional construction model data from the information terminal 3 (which may be any of the information terminals 3a to 3c). The information terminal 3 accepts input of three-dimensional construction model data to be sent to the computer 10 from a user via a predetermined UI (User Interface), and transmits the accepted three-dimensional construction model data to the computer 10. The three-dimensional construction model data acquisition module receives this three-dimensional construction model data and acquires the three-dimensional construction model data. Note that the three-dimensional construction model data acquisition module can also be configured to acquire three-dimensional construction model data from sources other than the information terminal 3, such as an external system (not shown).

[0031] The 3D model generation module generates a 3D model based on the acquired 3D construction model data (step S11). The 3D model generation module generates a BIM 3D model based on the acquired BIM data. Because the BIM data is a character string, the 3D model generation module 3D models this character string to generate the BIM 3D model. The method by which the 3D model generation module generates a BIM 3D model based on the BIM data is not particularly limited, and may be, for example, generated using a predetermined algorithm.

[0032] The 3D output module outputs a building based on the acquired 3D construction model data to multiple users in 3D (step S12), and also outputs the user identifiers of each user viewing the output building (step S13). The user identifier is an arbitrary character string (such as a name, management number, or ID) that indicates a user. The user identifier is pre-assigned to each user. The 3D output module outputs the generated BIM 3D model as a building based on the 3D construction model data to multiple users (each of a first user, a second user, and a third user). In addition, the 3D output module outputs the user identifiers of each user viewing the BIM 3D model ("User A" as the user identifier for the first user, "User B" as the user identifier for the second user, and "User C" as the user identifier for the third user). The 3D output module transmits a building (the generated BIM 3D model) based on the acquired 3D construction model data to each information terminal 3 (each of the information terminals 3a to 3c) used by each user who wishes to view the building. When transmitting the building to each information terminal 3, the 3D output module also transmits the user identifiers of all users who wish to view the building to each information terminal 3. At this time, the user identifiers output by the 3D output module may be placed on the building, near the building, in a blank space on the building, or elsewhere, and are not particularly limited. Furthermore, the user identifiers may be listed, such as a user list that compiles each user identifier, or may be iconized, such as an icon linked to each user identifier, or may be other identifiers, and are not particularly limited. In the building output process, an example will be described in which the 3D output module transmits the generated building to each of the information terminals 3a to 3c, along with the user identifiers of the first to third users. The information terminals 3a to 3c receive this building and display this building and the user identifiers of the users viewing this building via a predetermined UI (see FIG. 4).The three-dimensional output module displays the building and the user identifiers of each user viewing the building on each information terminal 3, thereby outputting a building based on the acquired three-dimensional construction model data in three dimensions to multiple users, and also outputs the user identifiers of each user viewing the output building.

[0033] The buildings and user identifiers output by the three-dimensional output module will be described with reference to FIG. 4. This figure is a diagram schematically illustrating the screens of the information terminals 3 (information terminals 3a and 3b) when the three-dimensional output module outputs the buildings and user identifiers. In this figure, the screen of information terminal 3a is shown as screen 20a, and the screen of information terminal 3b is shown as screen 20b. A first user (user identifier "user A") is viewing screen 20a, a second user (user identifier "user B") is viewing screen 20b, and a third user (user identifier "user C") is viewing a different screen (not shown). On screen 20a, there is a building 21a viewed by the first user and a user list 22a of each user viewing the building. The user list 22a lists the user identifiers of all users who will view the building output by the three-dimensional output module, and shows User A, the user identifier of the first user, User B, the user identifier of the second user, and User C, the user identifier of the third user. The user list 22a is arranged near the building 21a, and is located in the blank area at the top left of the screen 20a where the building 21a does not exist. Similarly, the screen 20b shows the building 21b viewed by the second user and user lists 22b of each user who will view the building. Like the user list 22a, the user list 22b lists the user identifiers of all users who will view the building output by the three-dimensional output module, and shows User A, the user identifier of the first user, User B, the user identifier of the second user, and User C, the user identifier of the third user. Like the user list 22a, the user list 22b is arranged near the building 21b, and is located in the blank area at the top left of the screen 20b where the building 21b does not exist.

[0034] The above is the building output process. The user can view the building output as a result of the building output process at any time from a position, direction, or angle that the user desires.

[0035] Note that, when outputting a building, the computer 10 can also be configured to place within the building a viewpoint icon indicating the user viewpoint of each user retained as a result of a user viewpoint acquisition process described below. This case will be described. The viewpoint icon placement module places within the building a viewpoint icon indicating each retained user viewpoint. The viewpoint icon is a predetermined icon, for example, a camera icon. The viewpoint icon placement module places within the building a viewpoint icon associated with each retained user viewpoint. The viewpoint icon placement module places the viewpoint icon at a position within the building corresponding to the position of the user's viewpoint in the user viewpoint. Furthermore, the viewpoint icon placement module places the viewpoint icon with its orientation aligned with the direction and angle of the user's viewpoint. Note that the viewpoint icon may be placed with its orientation aligned with either the direction or orientation of the acquired user viewpoint. The three-dimensional output module outputs the building with the viewpoint icon placed. Note that the format of the viewpoint icon is not particularly limited and can be designed as appropriate.

[0036] Furthermore, the computer 10 can be configured to switch the display / hide of a viewpoint icon while it is being output. This case will be described. The viewpoint icon switching module accepts a predetermined input from the user (such as a tap on an icon to switch the display / hide of the viewpoint icon) and switches the display / hide of the output viewpoint icon. The information terminal 3 accepts this predetermined input from the user and transmits the accepted input content to the computer 10. The computer 10 receives this input content and accepts an input from the user to switch the display / hide of the viewpoint icon. Upon accepting this predetermined input, the viewpoint icon switching module changes the viewpoint icon to a hidden state when the viewpoint icon is displayed, and changes the viewpoint icon to a displayed state when the viewpoint icon is not displayed. The computer 10 transmits a command to switch the display / hide state of the viewpoint icon displayed by the information terminal 3 based on the changed display / hide state of the viewpoint icon. The information terminal 3 receives this command and switches the display / hide of the viewpoint icon.

[0037] [User viewpoint acquisition process executed by computer 10] The user viewpoint acquisition process executed by the computer 10 will be described with reference to Figure 5. This figure shows a flowchart of the user viewpoint acquisition process executed by the computer 10. The user viewpoint acquisition process is a detailed description of a user viewpoint acquisition process (step S3) that acquires the position, direction, or angle of the viewpoint of each user viewing a building as the user viewpoint of each user, and a retention process (step S4) that retains each acquired user viewpoint. The user viewpoint acquisition process is a process that is performed whenever the building and the user identifiers of each user are output.

[0038] The user viewpoint acquisition module acquires the position, direction, or angle of the viewpoint of each user viewing the building as the user viewpoint of each user (step S20). The user viewpoint acquisition module acquires each parameter of the position, direction, or angle of each user's viewpoint from the information terminal 3 through which each user is viewing the building. The user viewpoint may be any one of the position, direction, or angle of each user's viewpoint, or a combination of multiple parameters, or all of them. In the following explanation, the case where the user viewpoint is the position, direction, and angle of each user's viewpoint will be explained as an example.

[0039] The user's viewpoint will be described with reference to FIG. 6. This figure is a diagram schematically illustrating a coordinate system used to determine the position, direction, and angle of the user's viewpoint. In this figure, a coordinate system 30 is shown, with point P indicating the user's position. The position of the user's viewpoint is determined by the coordinates (x, y, z) of point P'. The direction of the user's viewpoint is determined by the vector r connecting points P and P', with the direction toward the central axis as the base point being (-) and the direction away from the central axis being (+). The angle of the user's viewpoint is determined by the angle α of vector r in the xy plane and the angle δ of vector r in the yz plane. In FIG. 5, the coordinates (x, y, z) of point P' are determined by the following equation 1. Formula 1

[0040]

[0041] In the above formula, as described above, (x, y, z) are the coordinates of point P', r is the vector connecting point P and point P', angle α is the angle of vector r in the xy plane, and angle δ is the angle of vector r in the yz plane. The position, direction, and angle of the user's viewpoint are determined using the above formula. When determining the user's viewpoint, the user's viewpoint may be determined based on only one of the position, direction, or angle of the user's viewpoint, or a combination of multiple factors. In this case, the position, direction, or angle of the user's viewpoint may be determined based on only the position of the user's viewpoint, the position and direction of the user's viewpoint, the position and angle of the user's viewpoint, only the direction of the user's viewpoint, or only the angle of the user's viewpoint, etc.

[0042] The information terminal 3 transmits the determined parameters of the position, direction, and angle of the user's viewpoint to the computer 10. The user viewpoint acquisition module receives these parameters for each user viewing the building and acquires the position, direction, and angle of the viewpoint of each user viewing the building as the user viewpoint of each user. At this time, the user viewpoint acquisition module acquires the user identifier of each user along with the user viewpoint of each user. That is, the user viewpoint acquisition module acquires the user viewpoint and user identifier of a first user viewing the building, the user viewpoint and user identifier of a second user viewing the building, and the user viewpoint and user identifier of a third user viewing the building.

[0043] The storage module stores each acquired user viewpoint (step S21). The storage module stores each acquired user viewpoint by linking it to the user identifier of each user. At this time, the storage module may update the user viewpoint to the latest one as needed, or may store the user viewpoint after adding a timestamp or the like to the user viewpoint.

[0044] This completes the user viewpoint acquisition process.

[0045] [User viewpoint switching process executed by computer 10] The user viewpoint switching process executed by computer 10 will be described with reference to Figure 7. This figure shows a flowchart of the user viewpoint switching process executed by computer 10. The user viewpoint switching process includes a user identifier reception process (step S5) that receives a selection of a user identifier from a first user viewing the output building, and a user viewpoint switching process (step S6) that switches the user viewpoint of the first user to the user viewpoint of a second user corresponding to the received user identifier based on the received user identifier and each user viewpoint held. The user viewpoint switching process is performed whenever the building and the user identifiers of each user are output.

[0046] The user identifier reception module accepts a selection of a user identifier from the first user viewing the output building (step S30). The information terminal 3a accepts input from the first user to view the building from the user perspective of another user desired by the first user. For example, the information terminal 3a accepts a selection input (such as a tap on the user identifier) ​​of the user identifier of another user desired by the first user from among the user identifiers present in the user list 22a in FIG. 4. The information terminal 3a transmits the user identifier for which selection input has been accepted to the computer 10. The user identifier reception module receives this user identifier and accepts a selection of a user identifier from the first user viewing the output building.

[0047] The user viewpoint switching module switches the user viewpoint of the first user to the user viewpoint of the second user corresponding to the received user identifier based on the received user identifier and the retained user viewpoints (step S31). The user viewpoint switching module identifies the user corresponding to the received user identifier. In the processing of step S31, an example will be described in which the received user identifier is "user B" in FIG. 4. The user viewpoint switching module identifies the second user, who is linked to the user identifier of "user B," as the corresponding user. The user viewpoint switching module references the user viewpoints retained by the processing of step S21 and identifies the user viewpoint of the identified second user. The user viewpoint switching module switches the user viewpoint of the first user to the user viewpoint of the identified second user. The user viewpoint switching module changes the position, direction, and angle parameters of the first user's viewpoint to the retained position, direction, and angle parameters of the second user's viewpoint, and switches the user viewpoint of the first user to the user viewpoint of the second user. The user viewpoint of the second user may be any one of the position, direction, and angle of the viewpoint of the second user, or may be a combination of a plurality of these, or may be all of them.

[0048] The user viewpoint output module outputs the user viewpoint after the switch (step S32). The user viewpoint output module transmits the user viewpoint after the switch to the information terminal 3. The information terminal 3 receives this user viewpoint after the switch and, in the processing of step S12, displays the building that was displayed from the original user viewpoint from the user viewpoint of the other user after the switch. In the example described above, the user viewpoint output module transmits the user viewpoint of the second user to the information terminal 3a. The information terminal 3a receives this user viewpoint of the second user and, in the processing of step S12, switches the building 21a that was displayed from the original user viewpoint of the first user to the building 21b, which is the user viewpoint of the second user, and displays it (see FIG. 8). The user viewpoint output module outputs the user viewpoint after the switch to the information terminal 3 by displaying the building from the user viewpoint of the other user after the switch.

[0049] Referring to FIG. 8, the user viewpoint after switching output by the user viewpoint output module will be described. This figure is a diagram schematically illustrating the screen of the information terminal 3a when the user viewpoint output module outputs the user viewpoint of the second user to the information terminal 3a. This figure shows a screen 40 of the information terminal 3a. A first user (user identifier: "User A") is viewing the screen 40. The screen 40 shows a building 41 from the user viewpoint of the second user and a user list 42 of each user viewing the building 41. The building 41 is similar to the building 21b in FIG. 4, and the user list 42 is substantially similar to the user list 22 in FIG. 4, but the display style (e.g., change of background color, change of text color, change of border, change of text size, addition of icon, addition of mark) for the user identifier whose selection has been accepted in the processing of step S30 is different from that of other users whose selection has not been accepted. In the user list 42, the user identifier 43 of the second user whose selection has been accepted is shown by hatching, indicating that the display mode has been changed to a different one from the user identifiers 44 of the first and third users whose selections have not been accepted. The first user can view this screen 40 and view the output building from the user perspective of the second user.

[0050] The above is the user viewpoint switching process.

[0051] [Following Process Executed by Computer 10] The following describes the following process executed by the computer 10 with reference to FIG. 9. FIG. 9 is a flowchart of the following process executed by the computer 10. The following process is executed after the user's user viewpoint is switched to that of another user as a result of the user viewpoint switching process. The following process is executed when the first user has not changed the user viewpoint of the other user to whom the user has been switched. In the following description, an example is taken of the following case where the first user (user identifier: "User A") views a building from the user viewpoint of the second user (user identifier: "User B") as a result of the user viewpoint switching process. It goes without saying that the following process is also applicable when the second user is another user.

[0052] The analysis module analyzes changes in the user viewpoint of the second user (step S40). The analysis module analyzes whether a change has occurred in the user viewpoint of the second user currently viewed by the first user. If a change has occurred, the analysis module also analyzes the amount of change (the amount of change in each parameter of the user viewpoint). The analysis module analyzes the user viewpoint of the second user currently viewed by the first user among the user viewpoints held by the processing of step S21, and analyzes whether or not the user viewpoint of the second user has changed, and if so, the amount of change in each parameter of the user viewpoint. The analysis module analyzes whether or not the user viewpoint of the second user has been updated, whether or not the timestamp has changed, etc., and analyzes changes in the user viewpoint of the second user. If a change has occurred in the user viewpoint of the second user, the analysis module also analyzes the amount of change in the user viewpoint of the second user (the amount of change in each parameter of the user viewpoint).

[0053] The change determination module determines whether or not there is a change in the user viewpoint of the second user (step S41). If the change determination module determines, based on the analysis result of the user viewpoint of the second user, that there is no change in the user viewpoint of the second user (no change in the user viewpoint based on the analysis result) (step S41 NO), the tracking process is terminated.

[0054] On the other hand, if the change determination module determines based on the analysis result of the user viewpoint of the second user that there has been a change in the user viewpoint of the second user (that there has been a change in the user viewpoint based on the analysis result) (step S41, YES), the tracking module causes the user viewpoint of the first user viewing the building from the user viewpoint of the second user to follow the change in the user viewpoint of the second user (step S42). The tracking module changes the user viewpoint of the first user currently viewing the building from the user viewpoint of the second user in accordance with the amount of change in the user viewpoint of the second user that has been analyzed, and causes the user viewpoint of the first user to follow the change in the user viewpoint of the second user. The tracking module may track the user viewpoint of the first user in real time to follow the change in the user viewpoint of the second user, or may track the change at a predetermined timing (e.g., when the change in the user viewpoint of the second user has ended). In addition, the following in the processing of step S42 may mean changing the user viewpoint of the first user in real time to match changes in the user viewpoint of the second user, or may mean changing at a predetermined timing to the user viewpoint of the second user at this predetermined timing.

[0055] The user viewpoint output module outputs the user viewpoint after tracking (step S43). The user viewpoint output module transmits the user viewpoint after tracking to the information terminal 3a. The information terminal 3a receives this user viewpoint after tracking, and in the processing of step S32, tracks and displays the building from the user viewpoint of the second user after tracking, instead of the building displayed from the user viewpoint of the second user before tracking. The user viewpoint output module outputs the user viewpoint after tracking by causing the information terminal 3a to display the building from the user viewpoint of the second user after tracking.

[0056] This completes the tracking process.

[0057] [Re-tracking process executed by computer 10] The re-tracking process executed by the computer 10 will be described with reference to FIG. 10. This figure shows a flowchart of the re-tracking process executed by the computer 10. The re-tracking process is a process executed after the user's user viewpoint is switched to that of another user as a result of the user viewpoint switching process. The re-tracking process is a process executed when the first user changes the user viewpoint of the other user. In the re-tracking process, an example will be described in which, as a result of the user viewpoint switching process, the first user (user identifier: "user A") views a building from the user viewpoint of the second user (user identifier: "user B"). It goes without saying that the re-tracking process is also applicable when the second user is another user. Detailed descriptions of processes similar to those described above will be omitted.

[0058] The analysis module analyzes changes in the user viewpoint of the first user (step S50). The analysis module analyzes whether a change has occurred in the user viewpoint of the second user currently viewed by the first user. If a change has occurred, the analysis module also analyzes the amount of change (the amount of change in each parameter of the user viewpoint). Of the user viewpoints retained by the processing of step S21, the analysis module analyzes the user viewpoint of the first user who is currently viewing the building from the user viewpoint of the second user, and analyzes whether or not the user viewpoint of the first user has changed, and if so, the amount of change in each parameter of the user viewpoint. The analysis module analyzes whether or not the user viewpoint of the first user has been updated, whether or not the timestamp has changed, etc., to analyze changes in the user viewpoint of the first user.

[0059] The change determination module determines whether the first user's user viewpoint has changed (step S51). If the change determination module determines based on the analysis result of the first user's user viewpoint that there has been no change in the first user's user viewpoint (no change in the user viewpoint based on the analysis result) (step S51 NO), the re-tracking process ends. In this case, the computer 10 executes the above-described tracking process.

[0060] On the other hand, if the change determination module determines based on the analysis result of the user viewpoint of the first user that there is a change in the user viewpoint of this first user (that there is a change in the user viewpoint based on the analysis result) (step S51 YES), the analysis module analyzes the change in the user viewpoint of the second user (step S52). The process of step S52 is the same as the process of step S40 described above.

[0061] The change determination module determines whether or not there is a change in the user viewpoint of the second user (step S53). If the change determination module determines, based on the analysis result of the user viewpoint of the second user, that there is no change in the user viewpoint of the second user (no change in the user viewpoint based on the analysis result) (step S53 NO), the re-tracking process is terminated.

[0062] On the other hand, if the change determination module determines based on the analysis result of the user viewpoint of the second user that there has been a change in the user viewpoint of the second user (that there has been a change in the user viewpoint based on the analysis result) (step S53, YES), the re-tracking module causes the user viewpoint of the first user viewing the building from the user viewpoint of the second user to re-track in accordance with the change in the user viewpoint of the second user (step S54). The re-tracking module re-tracks the user viewpoint of the first user, who is currently viewing the building from the user viewpoint of the second user, which has changed to a user viewpoint different from that of the second user, in accordance with the change in the user viewpoint of the second user, in accordance with the change in the user viewpoint of the second user. The re-tracking module may re-track the user viewpoint of the first user in real time in accordance with the change in the user viewpoint of the second user, or may re-track at a predetermined timing (such as the timing when the change in the user viewpoint of the second user has ended). In addition, the re-tracking in the processing of step S54 may involve changing the user viewpoint of the first user in real time in accordance with changes in the user viewpoint of the second user, or may involve changing the user viewpoint of the first user at a predetermined timing to the user viewpoint of the second user at this predetermined timing.

[0063] The user viewpoint output module outputs the user viewpoint after re-tracking (step S55). The user viewpoint output module transmits the user viewpoint after re-tracking to the information terminal 3a. The information terminal 3a receives this user viewpoint after re-tracking, and in the processing of steps S50 and S51, re-tracks and displays the building from the user viewpoint of the second user after re-tracking, replacing the building displayed from the user viewpoint of the first user where the change occurred. The user viewpoint output module outputs the user viewpoint after re-tracking by displaying the building from the user viewpoint of the second user after re-tracking on the information terminal 3a.

[0064] This completes the re-tracking process.

[0065] [Bookmark list sharing process executed by computer 10] The bookmark list sharing process executed by the computer 10 will be described with reference to Fig. 11. The figure shows a flowchart of the bookmark list sharing process executed by the computer 10. The bookmark list sharing process is a process executed after each user's viewpoint is retained as a result of the user viewpoint acquisition process. In the bookmark list sharing process, an example will be described in which a second user shares a bookmark registered by a first user. It goes without saying that the bookmark list sharing process is also applicable when the second user is another user.

[0066] The bookmark receiving module receives a bookmark of a user viewpoint held by the first user (step S60). The bookmark is used to register each user viewpoint desired by the first user. The information terminal 3a receives a bookmark input from the first user via a predetermined UI. For example, the information terminal 3a receives a predetermined input for the output user identifier (such as tapping the user identifier for which a bookmark is desired). The information terminal 3a transmits the user identifier for which the bookmark was received to the computer 10. The bookmark receiving module receives this user identifier and receives a bookmark of the user viewpoint held by the first user.

[0067] The bookmark list generation module generates a bookmark list that compiles the received bookmarks from the user's perspective (step S61). The bookmark list is a list of received user identifiers compiled in a predetermined format such as a list or table, for example, a list of received user identifiers. The bookmark list generation module compiles the received bookmarks with the accepted user identifiers to generate a bookmark list. Note that the format of the bookmark list is not particularly limited and can be designed as appropriate.

[0068] The list sharing module shares the generated bookmark list with the second user (step S62). The list sharing module transmits the generated bookmark list to the second user. The information terminal 3b receives and displays this bookmark list. The list sharing module transmits the generated bookmarks to the information terminal 3b and displays them, thereby sharing the generated bookmark list with the second user. The list sharing module may display this bookmark list within a building, may display it in a blank space outside the building, may display it via a specified UI when the building is not displayed, or may display it by some other method.

[0069] The list selection receiving module receives from the second user a selection of a user viewpoint that exists in the shared bookmark list (step S63). The information terminal 3b receives from the second user a selection of a user viewpoint in order to view a building from a user viewpoint that exists in the bookmark list desired by the second user. The information terminal 3b receives a selection input (such as a tap on the user identifier) ​​of a user identifier of a user viewpoint that the second user desires from among the user identifiers present in the bookmark list. The information terminal 3b transmits the user identifier for which the selection input has been received to the computer 10. The list selection receiving module receives this user identifier and receives from the second user a selection of a user viewpoint that exists in the shared bookmark list.

[0070] The user viewpoint switching module switches the user viewpoint of the second user to the received user viewpoint (step S64). The user viewpoint switching module identifies the user associated with the received user identifier as the corresponding user. The user viewpoint switching module references each user viewpoint retained by the processing of step S21 and identifies the user viewpoint of the identified user. The user viewpoint switching module switches the user viewpoint of the second user to the user viewpoint of the identified user. The user viewpoint switching module changes the position, direction, and angle parameters of the second user's viewpoint to the retained parameters of the position, direction, and angle of the identified user's viewpoint, and switches the user viewpoint of the second user to the user viewpoint of the identified user. Note that the user viewpoint of the identified user may be any one of the position, direction, or angle of the identified user's viewpoint, a combination of multiple parameters, or all of them.

[0071] The user viewpoint output module outputs the post-switching user viewpoint (step S65). The user viewpoint output module transmits the post-switching user viewpoint to the information terminal 3b. The information terminal 3b receives this post-switching user viewpoint and, in the processing of step S12, displays the building that was displayed from the original user viewpoint from the user viewpoint of the user who accepted the post-switching selection. The user viewpoint output module outputs the post-switching user viewpoint by causing the information terminal 3b to display the building from the user viewpoint of the user who accepted the post-switching selection.

[0072] The above is the bookmark list sharing process. Note that the computer 10 can also be configured to switch the display / hide state of a bookmark list when a second user is sharing the bookmark list. This case will be described below. The bookmark list switching module accepts a predetermined input (such as a tap on an icon for switching the display / hide state of the bookmark list) from the second user and switches the display / hide state of the shared bookmark list. The information terminal 3b accepts this predetermined input from the second user and transmits the accepted input to the computer 10. The computer 10 receives this input and accepts an input from the second user to switch the display / hide state of the bookmark list. Upon accepting this predetermined input, the bookmark list switching module changes the bookmark list to a hidden state if the bookmark list is displayed, and changes the bookmark list to a displayed state if the bookmark list is not displayed. The computer 10 transmits a command to switch the display / hide state of the bookmark list displayed by the information terminal 3b based on the changed display / hide state of the bookmark list. The information terminal 3b receives this command and switches the display / hide state of the bookmark list.

[0073] [Bookmark Icon Sharing Process Executed by Computer 10] The bookmark icon sharing process executed by the computer 10 will be described with reference to Fig. 12. The figure shows a flowchart of the bookmark icon sharing process executed by the computer 10. The bookmark icon sharing process is executed after each user's viewpoint is held as a result of the user viewpoint acquisition process. In the bookmark icon sharing process, a case in which a second user shares a bookmark registered by a first user will be described as an example. It goes without saying that the bookmark icon sharing process is also applicable when the second user is another user. Detailed descriptions of processes similar to those described above will be omitted.

[0074] The bookmark receiving module receives a bookmark from the first user for the user's viewpoint (step S70). The process of step S70 is the same as the process of step S60 described above.

[0075] The bookmark icon placement module places a bookmark icon indicating the user's viewpoint that received the bookmark within the building (step S71). The bookmark icon is a predetermined icon, such as a camera icon. The bookmark icon placement module places a bookmark icon associated with each user's viewpoint that received a bookmark within the building. The bookmark icon placement module places the bookmark icon at a position within the building that corresponds to the position of the user's viewpoint in the user's viewpoint. Furthermore, the bookmark icon placement module places the bookmark icon with its orientation aligned with the direction and angle of the user's viewpoint. Note that the bookmark icon may be placed with its orientation aligned with either the direction or orientation of the acquired user's viewpoint. Furthermore, the format of the bookmark icon is not particularly limited and can be designed as appropriate.

[0076] The icon sharing module shares the placed bookmark icon with the second user (step S72). The icon sharing module transmits the building with the bookmark icon placed thereon to the second user. The information terminal 3b receives this building and displays the building with the bookmark icon placed thereon. The icon sharing module transmits the building with the bookmark icon placed thereon to the information terminal 3b and displays it, thereby sharing the placed bookmark icon with the second user.

[0077] The icon selection receiving module receives a selection of a bookmark icon to be shared from the second user (step S73). The information terminal 3b receives a selection of a bookmark icon from the second user in order to view the building from a user perspective associated with the bookmark icon desired by the second user. The information terminal 3b receives a selection input (such as a tap on the bookmark icon) of the bookmark icon desired by the second user from among the bookmark icons arranged on the building. The information terminal 3b transmits the received bookmark icon to the computer 10. The information terminal 3b may transmit data identifying the received bookmark icon itself to the computer 10, or may transmit parameters of the position, direction, and angle of the received bookmark icon to the computer 10. The icon selection receiving module receives the bookmark icon and receives a selection of a bookmark icon to be shared from the second user.

[0078] The user viewpoint switching module switches the viewpoint of the second user to the viewpoint of the third user corresponding to the accepted bookmark icon based on the accepted bookmark icon and the user viewpoint indicated by the bookmark icon (step S74). The third user is a user different from the first user and the second user. The user viewpoint switching module switches the viewpoint of the second user to the viewpoint of the third user associated with the accepted bookmark icon. The user viewpoint switching module changes the position, direction, and angle parameters of the second user's viewpoint to the position, direction, and angle parameters of the third user's viewpoint associated with the bookmark icon, and switches the user viewpoint of the second user to the user viewpoint of the third user. Note that the user viewpoint of the third user may be any one of the position, direction, or angle of the third user's viewpoint, a combination of a plurality of these, or all of them.

[0079] The user viewpoint output module outputs the user viewpoint after switching (step S75). The process of step S75 is the same as the process of step S65 described above.

[0080] The above is the bookmark icon sharing process. Note that the computer 10 can also be configured to switch the display / hide of a bookmark icon when a second user is sharing the bookmark icon. This case will be described below. The bookmark icon switching module accepts a predetermined input (such as a tap on an icon to switch the display / hide of the bookmark icon) from the second user and switches the display / hide of the shared bookmark icon. The information terminal 3b accepts this predetermined input from the second user and transmits the accepted input to the computer 10. The computer 10 receives this input and accepts an input from the second user to switch the display / hide of the bookmark icon. Upon accepting this predetermined input, the bookmark icon switching module changes the bookmark icon to a hidden state if the bookmark icon is displayed, and changes the bookmark icon to a displayed state if the bookmark icon is not displayed. The computer 10 transmits a command to switch the display / hide state of the bookmark icon displayed by the information terminal 3b based on the changed display / hide state of the bookmark icon. The information terminal 3b receives this command and switches the display / hide of the bookmark icon.

[0081] [Cancellation process executed by computer 10] The cancellation process executed by the computer 10 will be described with reference to Figure 13. The figure shows a flowchart of the cancellation process executed by the computer 10. The cancellation process is executed after the user viewpoint is switched as a result of the user viewpoint switching process. In the cancellation process, an example will be described in which a first user views a building from the user viewpoint of a second user. It goes without saying that the cancellation process can also be applied when the second user is another user. Detailed descriptions of processes similar to those described above will be omitted.

[0082] The cancellation acceptance module accepts cancellation of the accepted user identifier from the first user (step S80). The information terminal 3a accepts a predetermined input (such as a tap on the user identifier) ​​for canceling the user viewpoint of the second user currently viewing the information, and transmits the accepted input content to the computer 10. The cancellation acceptance module receives the input content and accepts cancellation of the accepted user identifier from the first user.

[0083] The user viewpoint switching module switches from the user viewpoint of the second user to the original user viewpoint of the first user based on the cancellation of the accepted user identifier (step S81). The user viewpoint switching module references the original user viewpoint of the first user retained by the processing of step S21 and switches from the user viewpoint of the second user currently viewing to the original user viewpoint of the referenced first user. The user viewpoint switching module changes the parameters of the position, direction, and angle of the viewpoint of the second user currently viewing to the parameters of the original position, direction, and angle of the first user retained, and switches the user viewpoint of the first user from the user viewpoint of the second user to the original user viewpoint of the first user. Note that the user viewpoint of the first user may be any one of the position, direction, or angle of the viewpoint of the first user, a combination of a plurality of these, or all of them.

[0084] The user viewpoint output module outputs the post-switching user viewpoint (step S82). The user viewpoint output module transmits the post-switching user viewpoint to the information terminal 3a. The information terminal 3a receives this post-switching user viewpoint and, in a user viewpoint switching process, switches the building that was displayed from the user viewpoint of the second user to the building displayed from the original user viewpoint of the first user before switching. The user viewpoint output module outputs the post-switching user viewpoint by causing the information terminal 3a to display the building from the original user viewpoint of the first user before switching.

[0085] The above is the cancellation process. Note that when the computer 10 executes the cancellation process in the above-described tracking process and / or re-tracking process, the user viewpoint switching module may, in addition to switching to the original user viewpoint of the first user, stop following the user viewpoint of the second user that was being followed (maintaining the user viewpoint of the second user at the time when the cancellation process was executed) or stop re-tracking the user viewpoint of the second user (maintaining the user viewpoint of the second user at the time when the cancellation process was executed, or maintaining the user viewpoint of the first user after the change).

[0086] Although the above-described processes are described as separate processes, the computer 10 can be configured to execute a combination of some or all of the above-described processes. Furthermore, the computer 10 can also be configured to execute each process at a timing other than the timing described. Furthermore, although the above-described processes are described as processes executed by the computer 10, some or all of the processes can also be executed by the information terminal 3 itself or a specific application installed on the information terminal 3.

[0087] The above-described means and functions are realized by a computer (including a CPU, an information processing device, and various terminals) reading and executing a predetermined program. The program may be provided, for example, from a computer via a network (Software as a Service (SaaS)) or as a cloud service. The program may also be provided in a form recorded on a computer-readable recording medium. In this case, the computer reads the program from the recording medium, transfers it to an internal or external recording device, records it, and executes it. The program may also be pre-recorded on a recording device (recording medium) and provided to the computer from the recording device via a communication line.

[0088] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Furthermore, the effects described in the embodiments of the present invention are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

[0089] A first aspect disclosed in this embodiment is a construction model viewpoint switching system that switches the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer, comprising: a three-dimensional construction model data acquisition unit that acquires the three-dimensional construction model data; a three-dimensional output unit that outputs a building based on the acquired three-dimensional construction model data to multiple users in three dimensions and outputs the user identifier of each user viewing the output building; a user viewpoint acquisition unit that acquires the position, direction, or angle of the viewpoint of each user viewing the building as the user viewpoint of each user; a storage unit that stores each of the acquired user viewpoints; a user identifier acceptance unit that accepts a selection of the user identifier from a first user viewing the output building; and a user viewpoint switching unit that switches the user viewpoint of the first user to the user viewpoint of a second user corresponding to the accepted user identifier based on the accepted user identifier and each of the held user viewpoints.

[0090] A second aspect disclosed in this embodiment provides the construction model viewpoint switching system according to the first aspect, further comprising: a bookmark receiving unit that receives, from the first user, a bookmark of the user viewpoint that is held.

[0091] A third aspect disclosed in this embodiment provides the construction model viewpoint switching system according to the second aspect, further comprising: a list generation unit that generates a bookmark list that compiles the received bookmarks of the user viewpoints.

[0092] A fourth aspect disclosed in this embodiment provides a construction model viewpoint switching system as described in the third aspect, further comprising: a list sharing unit that shares the generated bookmark list with the second user; and a list selection receiving unit that receives from the second user a selection of the user viewpoint that exists in the bookmark list to be shared, wherein the user viewpoint switching unit switches the user viewpoint of the second user to the received user viewpoint.

[0093] A fifth aspect disclosed in this embodiment provides a construction model viewpoint switching system according to the second aspect, further comprising: a bookmark icon placement unit that places a bookmark icon indicating the user viewpoint that has accepted a bookmark within the building.

[0094] A sixth aspect disclosed in this embodiment provides a construction model viewpoint switching system according to the fifth aspect, further comprising: an icon sharing unit that shares the placed bookmark icon with the second user; and an icon selection receiving unit that receives a selection of the shared bookmark icon from the second user, wherein the user viewpoint switching unit switches the user viewpoint of the second user to the user viewpoint of a third user that corresponds to the accepted bookmark icon, based on the accepted bookmark icon and the user viewpoint indicated by the bookmark icon.

[0095] A seventh aspect disclosed in this embodiment provides the construction model viewpoint switching system according to the fifth aspect, further comprising: a bookmark icon switching unit that switches between displaying and hiding the arranged bookmark icon.

[0096] An eighth aspect disclosed in this embodiment provides a construction model viewpoint switching system according to the first aspect, further comprising: a tracking unit that, when the second user changes his / her user viewpoint, tracks the user viewpoint of the first user viewing the building from the user viewpoint of the second user in accordance with the change in the user viewpoint of the second user.

[0097] A ninth aspect disclosed in this embodiment provides a construction model viewpoint switching system according to the first aspect, further comprising: a re-tracking unit that, when the first user changes his / her user viewpoint and then the second user changes his / her user viewpoint, re-tracks the user viewpoint of the first user viewing the building from the user viewpoint of the second user in accordance with the change in the user viewpoint of the second user.

[0098] A tenth aspect disclosed in this embodiment provides a construction model viewpoint switching system as described in the first aspect, further comprising: a cancellation receiving unit that receives cancellation of the accepted user identifier from the first user; and the user viewpoint switching unit switches from the user viewpoint of the second user to the original user viewpoint of the first user based on the accepted cancellation of the user identifier.

[0099] An eleventh aspect disclosed in this embodiment provides a construction model viewpoint switching system according to the first aspect, further comprising: a viewpoint icon placement unit that places viewpoint icons indicating each user viewpoint held within the building.

[0100] A twelfth aspect disclosed in this embodiment provides the construction model viewpoint switching system according to the eleventh aspect, further comprising: a viewpoint icon switching unit that switches between displaying and hiding the arranged viewpoint icon.

[0101] A thirteenth aspect disclosed in this embodiment provides a construction model viewpoint switching system according to the first aspect, further comprising: a three-dimensional model generation unit that generates a three-dimensional model based on the acquired three-dimensional construction model data; and the three-dimensional output unit outputs the generated three-dimensional model as the building.

[0102] REFERENCE SIGNS LIST 1 Construction model viewpoint switching system 3 Information terminal 8 Network 10 Computer 20 Screen 21 Building 22 User list 30 Coordinate system 40 Screen 41 Building 42 User list 43 User identifier 44 User identifier

Claims

1. A construction model viewpoint switching system that switches the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer, comprising: a three-dimensional construction model data acquisition unit that acquires the three-dimensional construction model data; a three-dimensional output unit that outputs a building based on the acquired three-dimensional construction model data to multiple users in three dimensions and outputs the user identifier of each user viewing the output building; a user viewpoint acquisition unit that acquires the position, direction, or angle of the viewpoint of each user viewing the building as the user viewpoint of each user; a storage unit that stores each of the acquired user viewpoints; a user identifier acceptance unit that accepts a selection of the user identifier from a first user viewing the output building; and a user viewpoint switching unit that switches the user viewpoint of the first user to the user viewpoint of a second user corresponding to the accepted user identifier based on the accepted user identifier and each of the held user viewpoints.

2. The construction model viewpoint switching system according to claim 1, further comprising: a bookmark receiving unit that receives a bookmark of the user viewpoint held by the first user.

3. The construction model viewpoint switching system according to claim 2, further comprising: a list generation unit that generates a bookmark list that compiles the received bookmarks of the user viewpoints.

4. The construction model viewpoint switching system of claim 3 further comprises: a list sharing unit that shares the generated bookmark list with the second user; and a list selection receiving unit that receives a selection of the user viewpoint that exists in the shared bookmark list from the second user, wherein the user viewpoint switching unit switches the user viewpoint of the second user to the received user viewpoint.

5. The construction model viewpoint switching system according to claim 2, further comprising: a bookmark icon placement unit that places, within the building, a bookmark icon indicating the user viewpoint for which a bookmark has been accepted.

6. The construction model viewpoint switching system of claim 5, further comprising: an icon sharing unit that shares the placed bookmark icon with the second user; and an icon selection receiving unit that receives a selection of the shared bookmark icon from the second user, wherein the user viewpoint switching unit switches the user viewpoint of the second user to the user viewpoint of a third user corresponding to the accepted bookmark icon based on the accepted bookmark icon and the user viewpoint indicated by the bookmark icon.

7. The construction model viewpoint switching system according to claim 5, further comprising: a bookmark icon switching unit that switches between displaying and hiding the arranged bookmark icon.

8. The construction model viewpoint switching system of claim 1, further comprising a tracking unit that, when the second user changes his / her user viewpoint, tracks the user viewpoint of the first user viewing the building from the user viewpoint of the second user in accordance with the change in the user viewpoint of the second user.

9. The construction model viewpoint switching system of claim 1, further comprising a re-tracking unit that, when the second user changes his or her user viewpoint after the first user changes the user viewpoint, re-tracks the user viewpoint of the first user viewing the building from the user viewpoint of the second user in accordance with the change in the user viewpoint of the second user.

10. The construction model viewpoint switching system of claim 1, further comprising a cancellation receiving unit that receives cancellation of the accepted user identifier from the first user, wherein the user viewpoint switching unit switches from the user viewpoint of the second user to the original user viewpoint of the first user based on the accepted cancellation of the user identifier.

11. The construction model viewpoint switching system according to claim 1, further comprising: a viewpoint icon placement unit that places viewpoint icons indicating each user viewpoint held within the building.

12. The construction model viewpoint switching system according to claim 11, further comprising a viewpoint icon switching unit that switches between displaying and hiding the arranged viewpoint icon.

13. The construction model viewpoint switching system according to claim 1, further comprising: a three-dimensional model generation unit that generates a three-dimensional model based on the acquired three-dimensional construction model data; and the three-dimensional output unit that outputs the generated three-dimensional model as the building.

14. A construction model viewpoint switching method executed by a computer for switching the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer, comprising the steps of: acquiring the three-dimensional construction model data; outputting a building based on the acquired three-dimensional construction model data to multiple users in three dimensions and outputting the user identifier of each user viewing the output building; acquiring the position, direction or angle of the viewpoint of each user viewing the building as the user viewpoint of each user; retaining each of the acquired user viewpoints; accepting a selection of the user identifier from a first user viewing the output building; and switching the user viewpoint of the first user to the user viewpoint of a second user corresponding to the accepted user identifier based on the accepted user identifier and each of the held user viewpoints.

15. A computer-readable program for causing a computer to execute the following steps for switching the viewpoint of a user viewing three-dimensional construction model data that reproduces a building on a computer: acquiring the three-dimensional construction model data; outputting a building based on the acquired three-dimensional construction model data in three dimensions to multiple users and outputting the user identifier of each user viewing the output building; acquiring the position, direction or angle of the viewpoint of each user viewing the building as the user viewpoint of each user; retaining each of the acquired user viewpoints; accepting a selection of the user identifier from a first user viewing the output building; and switching the user viewpoint of the first user to the user viewpoint of a second user corresponding to the accepted user identifier based on the accepted user identifier and each of the retained user viewpoints.

Images