JP2015079353A - Three-dimensional map display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional map in which an additional object other than a ground object is displayed three-dimensionally.SOLUTION: Projection image data is prepared in advance which displays ground objects such as a road and a building three-dimensionally by parallel projection. When displaying a three-dimensional map, a projection image is pasted on a ground surface in a virtual three-dimensional space, and on the projection image, a three-dimensional model of additional objects such as a bus and a train is disposed. Then, the virtual three-dimensional space, in other words an additional object and a projection image, is parallel-projected to display a three-dimensional map. By using both the projection image and the three-dimensional model of the additional objects, a three-dimensional map can be displayed with a slight process load while a real additional object is displayed.

Description

  The present invention relates to a three-dimensional map display system that displays a three-dimensional map representing a feature in a three-dimensional manner together with additional objects other than the feature.

  A three-dimensional map used in an apparatus such as a car navigation system is drawn by projecting a feature such as a building or a road by a method such as perspective projection. As disclosed in Patent Document 1, a technique for displaying a three-dimensional map using parallel projection instead of perspective projection is also disclosed. Since perspective projection is a projection performed after specifying a viewpoint, parallel projection does not need to determine a viewpoint for projection. Can be generated, and there is an advantage that the processing load at the time of display can be reduced.

  In order to improve the usefulness of a three-dimensional map, techniques for displaying various additional information in the map have also been proposed. Patent Document 2 uses a three-dimensional model of a movable object such as a vehicle or a signboard in a three-dimensional map together with features in a three-dimensional space and renders it by perspective projection while maintaining reality. Discloses a technology that enables a variety of information to be provided to a person.

Japanese Patent No. 4070507 Japanese Patent No. 3428294

In the method of Patent Document 2, it is necessary to project a movable object and a three-dimensional model of a large number of features, and there is a problem that a processing load during display is large.
As a method for reducing the processing load at the time of display, it is also possible to prepare a projection image of the entire area in advance and display a movable object prepared as a two-dimensional image in a superimposed manner as in Patent Document 1. However, in such a method, the reality as a three-dimensional map is lost, and additional information cannot be intuitively transmitted to the user. Considering that the movable object is directed in various directions, it is necessary to prepare a large number of two-dimensional images of the movable object, which causes another problem of increasing the data capacity.
Such a problem is not limited to the case where the additional information is a movable object, and is a common problem even with a static signboard or the like. The present invention has been made to solve these problems, and in a three-dimensional map, it is used with a light processing load by using a three-dimensional additional object prepared separately from features such as buildings and roads. It is intended to provide additional information to a person in a three-dimensional display manner.

The present invention
A three-dimensional map display system for displaying a three-dimensional map representing a three-dimensional feature,
A projection image database for storing projection image data as two-dimensional image display data generated by projecting a feature under a predetermined projection condition;
In addition to the features, an additional object 3D model database that stores a 3D model of the additional object to be displayed three-dimensionally in the 3D map;
A display control unit for displaying a three-dimensional map with reference to the projection image database and the additional object three-dimensional model database;
The display control unit
Pasting the projection image data on the ground surface in a virtual three-dimensional space,
Thereafter, the additional object 3D model is arranged in the virtual 3D space,
By projecting the virtual three-dimensional space, a three-dimensional map display system that displays the three-dimensional map can be configured.

According to the 3D map display system of the present invention, since a 3D map is displayed using projection image data prepared in advance, it is not necessary to perform projection processing of a large amount of features at the time of display, and the display processing load is reduced. Can be reduced. Further, since the additional object is prepared as a three-dimensional model, it is possible to provide information using the additional object without impairing the reality as a three-dimensional map.
The combined use of the projection image data and the additional object is performed by arranging the additional object on the projection image data pasted on the ground surface and projecting both. Since the projection process at the time of display is not completely eliminated, the additional object can be arranged at an arbitrary position and orientation in the virtual three-dimensional space and displayed on the three-dimensional map in order to perform the projection process at the time of display. Is possible. In addition, since the projection processing at the time of display is essentially only the projection of the additional object, the processing load at the time of display can be greatly reduced compared to the projection processing of a large amount of features. is there.
For the features, the projection processing is performed twice when the projection image is generated and displayed. However, in the present invention, the projection image is pasted on the ground surface of the virtual three-dimensional space and is used in a state having no height component, so that it is possible to suppress the influence of projection at the time of display, Excessive distortion can be suppressed.
As described above, in the present invention, by adopting a configuration in which a projection image that has already been subjected to projection processing and is originally unnecessary for further projection processing is pasted to the ground surface of the virtual three-dimensional space, It is possible to display a three-dimensional map by arranging a three-dimensional additional object at an arbitrary location on the map while reducing the processing load.

In the present invention, the projection for generating a projection image (hereinafter also referred to as “projection at generation”) may be either perspective projection or parallel projection. Since parallel projection does not require a viewpoint to be specified, a common projection image can be used in all areas. On the other hand, since a projection image by perspective projection changes depending on the position of the viewpoint, when perspective projection is used as the projection at the time of generation, projection images from a plurality of viewpoints and line-of-sight directions are prepared.
Further, the projection when displaying the three-dimensional map after arranging the additional object (hereinafter also referred to as “projection at the time of display”) may be either perspective projection or parallel projection. The projection method and the projection condition of the generation projection and the display projection may be the same or different.
The projection image data may be provided in any format of raster data and polygon data. However, the polygon data has an advantage that the entire data amount can be suppressed and an image can be provided with a high image quality because the image does not become rough when enlarged and displayed.
The additional object may be, for example, a vehicle such as a car, a bus, or an airplane, a person, a cloud, or other movable objects, or a stationary object such as a signboard, a guide board, or a sign.
These additional objects may be arranged at a fixed position or may be moved with time. By moving it, the movement of a car or a person can be represented by an animation. For example, the state of congestion, the route from the current position to the destination, etc. can be expressed visually and intuitively.

In the three-dimensional map display system of the present invention,
By setting the position coordinates where the additional object is to be placed in an actual three-dimensional space, and converting the position coordinates under the projection conditions for generating the projection image data, the ground surface in the virtual three-dimensional space An additional object coordinate setting unit for generating the upper virtual position coordinates is provided,
The display control unit may display the three-dimensional map by arranging the additional object based on the virtual position coordinates and the height component in the actual three-dimensional space.

By doing so, the relationship between the feature and the additional object can be accurately displayed as described below.
In the present invention, the projection image to be pasted on the ground surface of the virtual three-dimensional space constitutes a coordinate system different from the orthogonal coordinate according to the projection condition. For example, in the case of perspective projection, two roads parallel to the line-of-sight direction are drawn as diagonal straight lines that intersect at the vanishing point on the projection image. In the case of parallel projection, the road in the depth direction orthogonal to the left-right direction is drawn as a road that obliquely intersects the road in the left-right direction on the projection image. In any case, an orthogonal coordinate system defined on the ground surface in an actual three-dimensional space (hereinafter sometimes referred to as “real space”) is converted into a coordinate system different from the orthogonal coordinates on the projection image. Will be. Therefore, even if the additional object is arranged in the virtual three-dimensional space according to the two-dimensional position coordinates in the actual three-dimensional space, the additional object is different from the original relative positional relationship with other features. Will be placed.
On the other hand, according to the above aspect, since the position coordinates in the actual three-dimensional space where the additional object is to be arranged can be converted into the coordinate system in the virtual three-dimensional space, the additional object can be accurately placed. It becomes possible to arrange in. As a result, for example, an additional object such as a car can be arranged or moved along the road of the projected image, and information according to geography can be expressed.
In the above aspect, the two-dimensional coordinates obtained by performing the coordinate conversion and the three components of the height component in the actual three-dimensional space are used to arrange in the virtual three-dimensional space. By doing so, the additional object is arranged while maintaining the height component in the virtual three-dimensional space. Therefore, additional objects such as airplanes and clouds can be arranged in the air in the virtual three-dimensional space, and a three-dimensional map that does not feel uncomfortable with these additional objects can be realized.

In the three-dimensional map display system of the present invention,
The projection for generating the projection image data, that is, the projection at the time of generation may be a parallel projection from an oblique direction inclined by a first projection angle with respect to the vertical direction.
Unlike the perspective projection, the parallel projection does not need to specify the viewpoint. Therefore, if parallel projection is used, the projection image generated for the entire area can be used in common regardless of the display range of the three-dimensional map. When it is desired to display a three-dimensional map in various gaze directions, it is only necessary to perform parallel projection under a plurality of projection conditions in which the gaze direction is changed, and use a plurality of types of projection images generated.
In parallel projection, unlike perspective projection, there is an advantage that the scales in the left-right direction and the depth direction are maintained even though the feature is expressed three-dimensionally. In other words, in the case of perspective projection, the farther away from the viewpoint position, the narrower the road width and road interval are displayed, whereas in the parallel projection, regardless of whether it is a distant view or a near view, the road width or road interval Such a scale is maintained. As a result, even when the additional object is arranged on the projection image, there is an advantage that the additional object can be used in a certain size without being enlarged or reduced depending on the position.

In the 3D map display system of the present invention, regardless of whether the projection at generation is a perspective projection or a parallel projection,
The projection in the virtual three-dimensional space, that is, the projection at the time of display may be parallel projection from an oblique direction inclined by a second projection angle with respect to the vertical direction.
Considering the influence of the projection at the time of display on the ground surface in the virtual 3D space, when using the parallel projection at the time of display, the axis of the depth direction in the 2D coordinate system on the ground surface of the virtual 3D space is used. It is sufficient to convert the angle to change, and distortion generated in the coordinate system can be suppressed as compared with perspective projection. Therefore, by using parallel projection as the projection at the time of display, it becomes possible to reduce unnaturalness caused by performing the projection process twice on the projected image.
In consideration of the effects described above for the projection method, it is more preferable to apply parallel projection to both generation-time projection and display-time projection. In this case, the pitch angle with respect to the two-dimensional plane among the projection directions in the parallel projection may be changed, but at least the projection direction, that is, the yaw angle is preferably common.

In the three-dimensional map display system of the present invention, various additional objects can be used.
For example, the additional object may be a vehicle used in public transportation.
In this case, an additional object trajectory database for storing additional object trajectory data representing a movement trajectory of the additional object in an actual three-dimensional space is provided.
The display control unit may display the three-dimensional map by arranging the additional object based on the additional object trajectory data.
In general, public transportation operates on a fixed movement path, such as traveling on a predetermined route in the case of a bus and traveling on a railroad in the case of a railroad. According to the said aspect, since such a movement locus | trajectory is memorize | stored and an additional object can be arrange | positioned based on this, the display according to the actual driving | running | working condition is realizable.
Such display may be performed by animation. By doing so, there is an advantage that the operation route of public transportation can be provided to the user more visually and intuitively. For example, for buses, route maps that display operation routes by drawing lines that represent routes in various colors on the map are often used. In such route maps, the destination is reached intuitively. It is not easy to find a route to do. On the other hand, in the 3D map, if the bus travels with animation along the operation route, the route passing through the destination can be easily and intuitively identified. The same applies to not only buses but also railways and other public transportation.
In the above aspect, the additional object trajectory data may be generated and stored in advance by an operator manually or the like, or may be acquired from the outside such as a server on the Internet.
Further, the additional object trajectory data may represent a trajectory in a coordinate system in an actual three-dimensional space, or may be coordinate-transformed to represent a trajectory in a coordinate system in a virtual three-dimensional space. If the latter mode is adopted, there is an advantage that the coordinate conversion in determining the arrangement of the additional object can be omitted.
In the above aspect, the additional object may be used properly according to the type of public transportation and the additional object trajectory data.

In the present invention, the various features described above are not necessarily all provided, and may be appropriately omitted or combined.
The present invention is not limited to the above-described three-dimensional map display system, and can be configured in various ways. For example, it may be configured as a 3D map display method for displaying a 3D map by a computer, or may be configured as a computer program for causing a computer to execute such display. Moreover, you may comprise as a computer-readable recording medium which recorded such a computer program.

It is explanatory drawing which shows the projection method of a three-dimensional map. It is explanatory drawing (1) which shows the example of a display of a three-dimensional map. It is explanatory drawing (2) which shows the example of a display of a three-dimensional map. It is explanatory drawing (1) which shows the example of a display which expanded the three-dimensional map. It is explanatory drawing (2) which shows the example of a display which expanded the three-dimensional map. It is explanatory drawing which shows the structure of a three-dimensional map display system. It is explanatory drawing which shows the content of additional object locus | trajectory data. It is explanatory drawing which shows the content of projection image data. It is explanatory drawing (1) which shows the coordinate system of a projection image. It is explanatory drawing (2) which shows the coordinate system of a projection image. It is explanatory drawing (3) which shows the coordinate system of a projection image. It is a flowchart of a projection image data generation process. It is a flowchart of a map display process. It is a flowchart of additional object locus data generation processing. It is explanatory drawing which shows the example of a display (1) of the additional object as a modification. It is explanatory drawing which shows the example of a display of the additional object as a modification (2). It is explanatory drawing which shows the example of a display of the additional object as a modification (3). It is explanatory drawing which shows the example of a display of the additional object as a modification (4).

A. 3D map projection method:
An embodiment of the present invention will be described by taking a 3D map display device that displays a 3D map on a display such as a computer, a smart phone or other portable terminal, and a navigation device by projecting a 3D model.

FIG. 1 is an explanatory diagram showing a method for projecting a three-dimensional map.
In the three-dimensional map display of the embodiment, first, as shown in the upper side of FIG. 1, a three-dimensional model representing a three-dimensional feature such as a building is arranged in a three-dimensional space, and this is projected by a camera a and projected. Generate an image. The upper side of FIG. 1 is merely a schematic view of the projection, and the projection method may be either perspective projection or parallel projection. Projection performed at this stage is sometimes referred to as generation-time projection. The generation projection may be performed at the time when the three-dimensional map is displayed, or may be performed in advance. In the present embodiment, an example will be described in which projection at generation is performed in advance and the projection image is stored as projection image data as a three-dimensional image.

The generated projection image is then pasted on the ground surface of the virtual three-dimensional space for displaying a three-dimensional map. The hatched portion on the lower side of FIG. 1 represents a state in which the projection image generated on the upper side of FIG. 1 is pasted on the ground surface. In this embodiment, the virtual three-dimensional space represents a space (a lower space in FIG. 1) where the projection image is pasted to the ground surface unless otherwise specified.
A three-dimensional model of the additional object displayed in the three-dimensional map is arranged on the ground surface on which the projection image is pasted. Additional objects are objects other than the features that make up the map, such as buildings and roads. For example, vehicles, buses, airplanes, and other vehicles, people, clouds, other movable objects, signs, information boards, It may be a stationary object such as a sign. In the figure, an example of a bus is shown.

  The coordinate system is different between the upper side and the lower side in FIG. The three-dimensional space (the space shown in the upper side of FIG. 1) in which the three-dimensional model is arranged to perform the projection at generation is a three-dimensional orthogonal coordinate system composed of x, y, and z, whereas the lower part of FIG. This is because, on the side, x, y, z before projection is converted into two-dimensional coordinates xp, yp by projection at the time of generation. In order to place the additional object three-dimensional model, the lower virtual three-dimensional space in FIG. 1 is also processed in the three-dimensional orthogonal coordinate system having the height component z. The position coordinates in the three-dimensional space (that is, the plane coordinates x, y, z on the upper side in FIG. 1) need to be arranged after being converted into the coordinate systems xp, yp after projection.

  In this way, the virtual three-dimensional space in which the additional object three-dimensional model is arranged is projected by the camera b as shown in the lower side of FIG. 1 to display a three-dimensional map. In the present embodiment, this projection may be referred to as a display time projection. By performing the generation projection, it is possible to display a three-dimensional map with additional objects. Further, by moving the position of the additional object three-dimensional model in the virtual three-dimensional space, an animation display in which the additional object moves in the three-dimensional map can be performed.

2 and 3 are explanatory diagrams illustrating display examples of a three-dimensional map. FIG. 2 shows a projected image, that is, an image obtained by projecting only a feature. Parallel projection is used as the projection during generation.
FIG. 3 shows an image obtained by performing a projection at the time of display after arranging a three-dimensional model such as a bus, a train, and a bus stop as an additional object on the projection image. The projection at the time of display is also a parallel projection. By doing so, a map in which the additional object is drawn three-dimensionally is displayed on the three-dimensional map.
For a feature such as a building, projection is performed twice, that is, when it is generated and when it is displayed, but it is not extremely unnatural as shown in FIG.
The bus is drawn three-dimensionally with postures corresponding to various traveling directions. In this embodiment, since the projection at the time of display is performed after the additional object three-dimensional model is arranged, it is possible to perform the three-dimensional display with various postures without preparing a model according to the posture of the additional object.

4 and 5 are explanatory diagrams illustrating an enlarged display example of a three-dimensional map. FIG. 4 shows a projected image of the feature. FIG. 5 shows a map obtained by pasting this projection image on the ground surface and arranging a bus, a stop, characters, etc. as additional objects and performing projection at the time of display. In this way, characters can also be arranged as additional objects. What is necessary is just to arrange | position the thing which stuck the character on the transparent board as an additional object. The additional object of the bus can be drawn as if it is traveling on the road as shown in the figure by converting the coordinate position in the actual three-dimensional space and placing it on the projected image.
Thus, according to the present embodiment, it is possible to display a three-dimensional map after displaying the additional object three-dimensionally. The additional object can be used to provide various information to the user. For example, by displaying an animation for moving a bus along a service route, the user can easily and intuitively recognize the bus route. In addition, static additional objects such as bus stops and characters can be used to present information tailored to the user's request in an easily recognizable manner.

B. System configuration:
A system configuration for realizing the map display shown in FIGS.
FIG. 6 is an explanatory diagram illustrating a configuration of the three-dimensional map display system in the embodiment. The example of a structure which displays a map on the display 300d of the smart phone 300 based on the map data provided from the server 200 via the network NE2 or the like is shown. As a terminal for displaying a map, a personal computer, a navigation device, or the like may be used. Further, the 3D map display system may be configured as a system that operates in a stand-alone manner, in addition to a system that includes a terminal such as the smartphone 300 and the server 200.
In the figure, a data generation device 100 that generates three-dimensional map data is also shown.

The smart phone 300 includes various functional blocks that operate under the main control unit 304. In the present embodiment, the main control unit 304 and each functional block are configured by installing software that realizes the respective functions, but part or all of them may be configured by hardware.
The transmission / reception unit 301 communicates with the server 200 via the network NE2. In the present embodiment, transmission / reception of map data and commands for displaying a three-dimensional map is mainly performed.
The command input unit 302 inputs an instruction from the user through an operation performed via the display 300d. As an instruction in this embodiment, a display range of a three-dimensional map, designation of enlargement / reduction, and the like are given.
The map information storage unit 305 is a buffer that temporarily stores map data provided from the server 200. When a map to be displayed moves from moment to moment as in route guidance, the map information storage unit 305 receives map data in an insufficient range from the server 200 and displays the map. In the present embodiment, a projection image generated in advance by the projection at the time of generation is stored as map data. Further, the three-dimensional model of the additional object arranged on the projection image (see the lower side in FIG. 1) is also stored in the map information storage unit 305.
The display control unit 306 displays a three-dimensional map on the display 300 d of the smartphone 300 based on the data provided from the map information storage unit 305. As previously shown in the lower side of FIG. 1, the display control non-306 306 pastes the projection image on the ground surface, arranges the additional object 3D model, and displays the 3D map by projecting the display. To do.

The server 200 includes functional blocks shown in the figure. In the present embodiment, these functional blocks are configured by installing software that realizes the respective functions, but a part or all of the functional blocks may be configured by hardware.
The map database 210 is a database for displaying a three-dimensional map. In this embodiment, map data including projection image data 211, additional object trajectory data 212, and additional object three-dimensional model 213 is stored. The projection image data 211 is data for three-dimensionally displaying features such as roads and buildings, and is two-dimensional polygon data obtained by parallel projection of a three-dimensional model of the features. The additional object trajectory data 212 is data for storing a trajectory of an additional object that moves along a predetermined route such as a train or a bus. The additional object three-dimensional model 213 is a model representing the three-dimensional shape of the additional object.
The transmission / reception unit 201 transmits / receives data to / from the smartphone 300 via the network NE2. In the present embodiment, transmission / reception of projection image data, an additional object three-dimensional model, and commands is mainly performed. The transmission / reception unit 201 also communicates with the data generation device 100 via the network NE1. In the present embodiment, the generated projection image data is mainly exchanged.
The database management unit 202 controls reading and writing of various data from the map database 210.
In the map database, network data that represents road shapes as links and nodes may be facilitated, and a route search unit may be provided in the server 200 for performing route search by a method such as Dijkstra method using network data. Good. In this case, the route search result can also be used as one of the additional object trajectory data.

The data generation device 100 includes functional blocks shown in the figure. In this embodiment, these functional blocks are configured by installing software that realizes the respective functions in a personal computer, but a part or all of the functional blocks may be configured by hardware.
The transmission / reception unit 105 exchanges data with the server 200 via the network NE1.
The command input unit 101 inputs an operator instruction via a keyboard or the like. In the present embodiment, designation of an area where map data is to be generated, designation of parallel projection parameters, and the like are included.
The 3D map database 104 is a database that stores a three-dimensional model used for generating map data. Electronic features representing a three-dimensional shape are stored for features such as roads and buildings. The 3D map database 104 can use a 3D model that is conventionally provided for displaying a 3D map by perspective projection.
The parallel projection unit 102 performs display by parallel projection based on the 3D map database 104 to generate projection image data. The displayed projection image is stored in the parallel projection data 103 and is stored in the projection image data 211 of the map database 210 of the server 200 via the transmission / reception unit 105.
The projection parameter setting unit 106 sets projection parameters such as a projection angle (pitch angle) and a projection direction (yaw angle) during parallel projection.

FIG. 7 is an explanatory diagram showing the contents of the additional object trajectory data.
The additional object trajectory data is data that stores a trajectory at the time of display in association with a moving additional object such as a bus or a train. “Object ID” is an identifier of additional object trajectory data. “Name” is a name representing the trajectory. For example, as shown, a bus route can be used as a name. The “three-dimensional model” is data that specifies a three-dimensional model of an additional object to be displayed in association with the additional object trajectory data. In this embodiment, the model ID assigned to the additional object three-dimensional model is recorded. The “trajectory” represents the movement path of the additional object in the form of a point sequence. In this embodiment, the three-dimensional position coordinates (x, y, z) and the traveling direction vectors (vx, vy, vz) at each point are stored for each point on the locus. By using three dimensions for both the position and the traveling direction, it is possible to represent the locus of an additional object that draws a three-dimensional locus such as an aircraft.
The additional object trajectory data may be generated, for example, manually by an operator. In the case of public transportation such as a bus or railroad, a route map of the public transportation may be analyzed to automatically set the trajectory.

The additional object three-dimensional model is data representing the three-dimensional shape of the additional object. The coordinates of polygons constituting the three-dimensional model are stored as “model ID” as the identifier, “name” of the additional object, and “shape”. In addition to various attributes, for example, information indicating whether the 3D model is a moving or stationary object, the type of car, bus, train, person, etc., the texture to be pasted on the 3D model, the surface color, etc. Information and the like may be stored together.
The additional object trajectory data and the additional object 3D model are associated with each other by “3D model” and “model ID”. When representing the locus of the “Bus ○ system” shown in the figure, “MB01” stored in “3D model” uses the additional object 3D model stored in “Model ID”. One additional object three-dimensional model may be used for a plurality of additional object trajectory data.

B. Projected image data:
FIG. 8 is an explanatory diagram showing the contents of the projection image data. It shows a state where data D1 and D2 are obtained from the three-dimensional data D3 by parallel projection. The three-dimensional data D3 is data in which the three-dimensional model of the building M3, the road R3, and the like are arranged in the three-dimensional space represented by the orthogonal coordinate system x, y, z on the plane P3.
When this three-dimensional data D3 is parallel-projected in the vertical direction (the direction of arrow A1 in the figure), the building M3 becomes data D1 expressed two-dimensionally like a rectangle M1 on the projection plane P1. The road R3 is also drawn as a three-way crossing at a right angle like the road R1. This corresponds to conventional two-dimensional map data. If the scale is not taken into consideration, the orthogonal coordinate system x, y representing the two-dimensional map coincides with the plane components x, y of the orthogonal coordinate system x, y, z representing the three-dimensional data D3. Accordingly, the trajectory of the route G1 passing through the road R1 can be expressed using the plane coordinates x and y in the real space as they are. When considering the scale, it is sufficient to multiply the coordinate value by a coefficient corresponding to the scale.
On the other hand, in the present embodiment, as projection at the time of generation, parallel projection is performed on a plane P2 in an oblique direction (in the direction of arrow A2 in the drawing) inclined by a predetermined projection angle with respect to the vertical direction. As a result, on the data D2, a building is displayed three-dimensionally like a building M2. The road R3 is also displayed in a state where the three-way intersection that is orthogonal like the road R2 intersects diagonally. Although the building M2 and the like are expressed three-dimensionally in the projected image, the data D2 is only projected two-dimensional display data. In this embodiment, polygon data for displaying the building M2 and the like is stored as the projection image data. In this case, individual polygon data may be used for the side wall and roof portion of the building M2, or the whole may be used as one polygon data. The window W may be prepared as a texture to be pasted on the wall of the building, that is, raster data, or the window may be prepared as individual polygon data.
The projection image data of the present embodiment is configured by two-dimensional data obtained by projecting each feature by oblique parallel projection in this way.

The advantages of using parallel projection as the generation projection process are as follows.
Unlike perspective projection, parallel projection does not require a viewpoint for projection. That is, if a projection image is obtained with projection parameters such as a projection angle and a projection direction, the projection image can be used regardless of the map display area. Therefore, when displaying a three-dimensional map, it is only necessary to cut out and display a necessary region from a projection image that has already been generated, without performing projection processing of a large number of feature data.
Further, unlike perspective projection, parallel projection also has an advantage that scales in the horizontal direction and depth direction are maintained after projection.
Although one type of projection image may be used, in the present embodiment, the projection direction is changed to eight types to facilitate eight types of projection images. By doing so, it is possible to draw a three-dimensional map viewed from various directions according to the user's designation.
However, it is also possible to use perspective projection as the projection at the time of generation. In this case, a projection image may be generated according to a number of preset viewpoints and line-of-sight directions.

  As is clear from the point that the three-way crossing is displayed on the road R2 so as to cross diagonally, the plane coordinate system x, y in the real space is not orthogonal coordinates but two axes xp crossing diagonally on the data D2. , Yp. Accordingly, the trajectory of the route G2 passing through the road R2 can be obtained by converting the coordinates x, y, z in the real space into a coordinate system represented by the axes xp, yp on the projection image by coordinate conversion.

9 to 11 are explanatory diagrams showing the coordinate system of the projected image. Examples of projected images of the area corresponding to the photograph of FIG. 9 are shown in FIGS.
FIG. 10 shows an output example of a two-dimensional map. In FIG. 10, the buildings corresponding to the buildings BL1 and BL2 in FIG. In the two-dimensional map, it is difficult to intuitively understand that these illustrated features correspond to the buildings BL1 and BL2 in FIG. In the two-dimensional map, the positional relationship between the buildings BL1 and BL2 is represented by two-dimensional position coordinates x and y. This coordinate value is the same as the plane component of the three-dimensional orthogonal coordinate in the actual three-dimensional space. In FIG. 10, when the traveling direction is represented as indicated by an arrow DA, the position and the direction of the arrow can be the actual position and direction in the three-dimensional space.
FIG. 11 shows an output example of a projection image by parallel projection. In FIG. 11, the buildings BL1 and BL2 are indicated by a dashed line. Since it is displayed in parallel projection, the scale of the map is maintained. Therefore, the positional relationship between the buildings BL1 and BL2 and the distance to the buildings located farther than these buildings can be grasped to the same extent as the two-dimensional map (FIG. 10).
Moreover, in FIG. 11, since the features are displayed three-dimensionally, the shapes of the buildings BL1 and BL2 can be intuitively recognized. While FIG. 11 is drawn as if looking down from above, a user who actually stands at this point looks at buildings BL1 and BL2 as if looking up from below as shown in FIG. Based on the above, it is possible to intuitively identify the buildings BL1 and BL2.
Since the parallel projection is performed, the orthogonal coordinate system in the real space is converted into the coordinate axes xp and yp in FIG. 11 (hereinafter, the coordinate systems xp and yp may be referred to as the projected coordinate system). The axis yp intersects diagonally with a slight angle with respect to the axis xp. Therefore, when displaying the route guidance (arrow DA in FIG. 10), the position and direction in the real space are converted into the coordinate system xp, yp in the projection image, thereby determining the position and direction. Can do. Depending on the projection conditions, the error between the plane coordinates x, y in the real space and the coordinate values xp, yp in the projected image may be relatively small. In such a case, the coordinate conversion is omitted. There is no problem.

D. Projection image data generation method:
FIG. 12 is a flowchart of the projection image data generation process. This is a process performed by the parallel projection unit 102 (see FIG. 6) of the data generation apparatus 100, and is a process executed by a CPU of a personal computer constituting the data generation apparatus 100 in terms of hardware.
When the process is started, the data generation device 100 inputs designation of a mesh to be processed (step S10). The 3D map database stores a three-dimensional model divided into meshes of a predetermined size, and a projection image is generated in units of meshes. The structure of the mesh is shown on the right side of the figure. In this example, it is assumed that the center mesh MP is designated as the target mesh. As a method for specifying the target mesh, a mesh-specific index, mesh coordinates, and the like can be used. A method may be used in which the data generation apparatus 100 analyzes a mesh including the coordinate value of a point designated by the operator on the map and sets this as a mesh to be processed.
Further, the data generation device 100 inputs parallel projection parameters, that is, a projection direction and a projection angle (step S12). The parallel projection parameters may be specified by the operator each time projection image data is generated, or a method of setting default parallel projection parameters in the data generation apparatus 100 in advance may be used.

  Next, the data generation device 100 reads a 3D map database for the target mesh and meshes in a predetermined range around the target mesh (step S14). In this embodiment, as shown in the diagram on the right side, a 3D map database belonging to meshes within two sections from the target mesh MP is read. This range can be set arbitrarily. The read 3D map database is temporarily stored in the memory of the data generation device 100.

The reason for reading the 3D map database including the periphery of the target mesh in this way is as follows. In this embodiment, the projection image data is generated by parallel projecting the three-dimensional projection image data included in the 3D map database. However, when map data is generated and managed by dividing it into meshes, there is a problem in that appropriate projection image data cannot be generated if parallel projection is performed in units of meshes.
Consider a case where projection image data corresponding to the hatched mesh MP in the figure is generated. In the 3D map database, meshes M11 to M55 exist around the mesh MP, and various features exist in each mesh. Here, consider a case where the feature B34 existing in the mesh M34 adjacent to the mesh MP is projected in parallel. If parallel projection is performed in the direction indicated by Vpj34 in the drawing, the upper part of the feature B34 is projected into the mesh MP. Thus, when generating projection image data by parallel projection, a part of a feature that does not exist in the mesh may be projected onto the mesh MP to be processed. Therefore, if the parallel projection is simply performed for each mesh, the projection image of the feature existing on the other mesh is lost, and appropriate projection image data cannot be obtained.
Therefore, in this embodiment, with respect to the mesh MP to be processed, meshes adjacent thereto (M22, M23, M24, M25, M32, M34, M42, M43, M44), and meshes further adjacent thereto ( M11 to M15, M21, M25, M31, M35, M41, M45, and M51 to M55) are read, parallel projection is applied to the entire meshes M11 to M55, and the mesh MP is supported. Projection image data is generated by cutting out a portion of the polygon. By doing so, parallel projection is also performed on the feature B34 existing in the adjacent mesh M34 during the processing of the mesh MP, so that the upper part can be converted into projection image data without omission.

In this embodiment, as described above, the meshes at positions from the mesh MP to be processed to the two sections are used, but the range used for generating the projection image data can be arbitrarily set. If the size of each mesh is sufficiently large compared to the size of the feature and there is no possibility that a feature that is two blocks away will be projected onto the mesh to be processed, one section, that is, the processing target Parallel projection may be performed using only a mesh directly adjacent to the mesh. Conversely, when the mesh size is smaller than the feature size, parallel projection may be performed using a range of three or more sections.
Furthermore, the range used for parallel projection need not be evenly arranged around the mesh MP to be processed, and may be biased in consideration of the projection direction. For example, consider the case of parallel projection in the direction of the arrow Vpj34 as shown in the figure. At this time, as a result of the feature B32 existing in the mesh M32 adjacent to the left side of the mesh MP being projected in the direction of the arrow Vpj32, the projection image is displayed on the left side of the feature B32. That is, in this projection direction, the feature B32 is not projected onto the mesh MP. Therefore, when processing the mesh MP, it is not necessary to use the mesh M32 for parallel projection.
Similarly, in the case of performing parallel projection with the projection direction of the arrow Vp in the drawing, it is sufficient if there are ranges (mesh M34, M35, M43 to M45, M53 to M55) surrounded by a thick line.
As described above, the range used for parallel projection may be set so as to be biased toward the projection direction with respect to the mesh MP to be processed.

  The data generation device 100 performs parallel projection on the 3D map database read by the above processing based on the parallel projection parameters specified in step S12 (step S16). By this processing, a projection image in which each feature is three-dimensionally expressed by parallel projection is displayed. In this embodiment, these display results are temporarily stored in the memory of the data generation device 100 as two-dimensional polygon data. The display result may be stored as raster data.

When the parallel projection is completed, the data generation device 100 cuts out a region corresponding to the target mesh from the generated polygon data (step S18). For polygons displayed across a plurality of meshes, only the portion in the target mesh is extracted and set as new polygon data.
Then, the data generation device 100 stores it as projection image data (step S20). In this embodiment, the data is transmitted to the server 200 (see FIG. 6) together with an instruction to store the projection image data 211.
By executing the above processing for all meshes, the projection image data 211 of this embodiment can be prepared.

E. Map display processing:
FIG. 13 is a flowchart of the map display process. This process is mainly executed by the display control unit 306 of the smartphone 300 as a terminal, and is a process executed by the CPU of the smartphone 300 in terms of hardware.
When the process is started, the smartphone 300 sets a map display range (step S50). You may make it receive the designation | designated from a user and may use a default setting.
Next, the smartphone 300 reads the projection image data of the region corresponding to the display range and pastes it on the ground surface of the virtual three-dimensional space (step S52). As the projection image data, data stored in the map information storage unit 305 of the smartphone 300 is used. If the projection image data is insufficient, the projection image data is acquired from the server 200. The projection image data is preferably pasted including the periphery of the display range.

The smartphone 300 acquires the three-dimensional position coordinates / posture of the additional object to be displayed in the map (step S54). For example, the additional object to be displayed may be specified by the user individually or based on the type of bus / train. Further, an additional object to be displayed may be automatically set in accordance with the display purpose of the map such as “investigating bus routes”.
The position coordinates and orientation of the additional object are stored in the additional object trajectory data. When the map information storage unit 305 of the smartphone 300 is insufficiently downloaded and stored in advance, the information is acquired from the server 200. In the case of an additional object that moves along a trajectory, such as a bus or train, the coordinate values and postures to be displayed may be gradually moved along the additional object trajectory data. As the movement method, for example, the movement speed or the movement amount may be set for each additional object, or the movement may be performed with a fixed movement amount.

When the three-dimensional position and orientation of the additional object are acquired, the smartphone 300 converts the planar position coordinates and orientation of the additional object into the projection coordinate system based on the projection conditions at the time of generating the projection image, that is, the projection conditions at the time of generation ( Step S56). Coordinate transformation is possible by multiplying a transformation matrix according to the projection conditions. In addition to transmitting the map database 210 from the server 200, the projection conditions may be transmitted to the smartphone 300, and the smartphone 300 may generate a conversion matrix. The conversion matrix generated by the server 200 may be the smartphone 300. You may make it transmit to.
The smartphone 300 arranges the three-dimensional model of each additional object in the virtual three-dimensional space according to the projected coordinates obtained as a result of the coordinate conversion described above (step S58). Then, the whole is rendered and a three-dimensional map is displayed (step S60). In this embodiment, parallel projection is applied as rendering at this time, that is, projection at the time of display. Projection parameters such as projection angle and projection orientation were also matched to the projection at the time of generation. The projection parameter may be a value different from the generation projection.

According to the embodiment described above, as shown in FIGS. 2 to 5, it is possible to display a three-dimensional map in which three-dimensional additional objects are arranged. In this embodiment, since the additional object is displayed by rendering the three-dimensional model by projection at the time of display, realistic display is possible.
In the above embodiment, only a projection image and an additional object pasted on the ground surface are arranged in the virtual three-dimensional space to be projected at the time of display, and a three-dimensional model of a large number of features. Is not necessarily arranged. Accordingly, the projection at the time of display can be executed with a very light load.
The projection image is subject to double projection processing, but depending on the conditions of projection at the time of generation and projection at the time of display, unnaturalness due to the double projection processing can be sufficiently suppressed. . In particular, if both the projection at the time of generation and the projection at the time of display are performed by parallel projection, it is possible to suppress a sense of incongruity to a degree that is hardly present.
In the above embodiment, by using the additional object, various additional information in addition to the three-dimensional map can be presented in a manner that the user can easily recognize visually and intuitively. For example, if an additional object such as a bus or a train is presented as an animation that moves along a route, the user can more easily identify the route that reaches the destination.
In this embodiment, the route search may be configured to be performed using an additional object.

F. Variation:
In this embodiment, in addition to the above-described embodiments, various modifications can be configured.
F1. Additional object trajectory data generation processing:
In the embodiment, the three-dimensional position coordinates / attitude of the additional object are represented by a real space orthogonal coordinate system, and the additional object is arranged after being converted into the projected coordinate system on the smartphone 300 side at the time of display. On the other hand, as described below, the trajectory data of the additional object may be prepared in advance in the projection coordinate system.
FIG. 14 is a flowchart of additional object trajectory data generation processing. This is a process executed by the server 200.
When this process is started, the server 200 inputs parallel projection parameters for the generation-time projection process (step S100). Based on this, a coordinate conversion matrix for converting the orthogonal coordinate system in the real space to the projected coordinates is generated (step S102).
Next, the server 200 reads the original trajectory data of the additional object (step S104). The original trajectory data is data that represents the trajectory of the additional object in the orthogonal coordinate system of the real space. As the original trajectory data, the additional object trajectory data in the embodiment can be used.
The server 200 converts the plane position coordinates and orientation constituting the original trajectory data into projected coordinates using a coordinate conversion matrix (step S106). Then, the conversion result is stored as additional object trajectory data (step S108).
Through the above processing, the additional object trajectory data is represented in the projected coordinate system that has already undergone coordinate transformation. Therefore, if the position and orientation of the additional object are determined based on the trajectory data, the smartphone 300 can arrange the additional object without further coordinate conversion (step S56 in FIG. 13), and display the additional object. It is possible to reduce the time processing addition.

F2. Additional objects in the variant:
In this embodiment, a wide variety of additional objects can be used. 15 to 18 are explanatory diagrams illustrating display examples of additional objects as modified examples.
FIG. 15 shows an example in which a large number of people are displayed as additional objects. By preparing a three-dimensional model of a person and storing arbitrary trajectories as additional object trajectory data, these can be displayed. By displaying a person as an additional object, it becomes possible to visually represent the degree of congestion of the person. In this example, each person may be displayed as an additional object, or a group of several persons may be displayed as a group of additional objects.
FIG. 16 shows an example in which ships and people are displayed as additional objects. It is also possible to use an additional object that moves on the water surface in this way.
FIG. 17 shows an example in which a roller coaster is displayed as an additional object. In this example, the roller coaster track itself is a static additional object, and the running roller coaster is drawn as an additional object as a movable object. The running of the roller coaster can be realized by preparing additional object trajectory data based on the trajectory. As described above, the additional object may be expressed by a combination of the static model and the movable object model. In the example of FIG. 17, the roller coaster not only travels on the ground surface but also travels three-dimensionally while changing the altitude. Since the virtual three-dimensional space in which the additional object is arranged is prepared as a three-dimensional space having a height component, it is possible to display the additional object with a change in altitude in this way.
FIG. 18 shows an example in which a ferris wheel is displayed as an additional object. The position of the Ferris wheel itself does not change, but the gondola rotates with time. Such display can be easily realized by changing the shape of the three-dimensional model of the ferris wheel over time.
In addition, various objects such as airplanes and clouds can be displayed as additional objects on the three-dimensional map.

The embodiment of the present invention has been described above. The three-dimensional map display system does not necessarily have all the functions of the above-described embodiments, and only a part may be realized. Moreover, you may provide an additional function in the content mentioned above.
Needless to say, the present invention is not limited to the above-described embodiments, and various configurations can be adopted without departing from the spirit of the present invention.
For example, in the embodiment, both the projection at the time of generation and the projection at the time of display are performed by parallel projection, but either one may be perspective projection.
In the embodiment, the part configured as hardware can be configured as software, and vice versa.

  The present invention relates to a three-dimensional map display system that displays a three-dimensional map representing a feature in a three-dimensional manner together with additional objects other than the feature.

DESCRIPTION OF SYMBOLS 100 ... Data generation apparatus 101 ... Command input part 102 ... Parallel projection part 103 ... Projection image data 104 ... 3D map database 105 ... Transmission / reception part 106 ... Projection parameter setting part 200 ... Server 201 ... Transmission / reception part 202 ... Database management part 210 ... Map Database 211 ... Projection image data 212 ... Additional object locus data 213 ... Additional object three-dimensional model 300 ... Smartphone 300d ... Display 301 ... Transmission / reception unit 302 ... Command input unit 304 ... Main control unit 305 ... Map information storage unit 306 ... Display control unit

Claims (7)

A three-dimensional map display system for displaying a three-dimensional map representing a three-dimensional feature,
A projection image database for storing projection image data as two-dimensional image display data generated by projecting a feature under a predetermined projection condition;
In addition to the features, an additional object 3D model database that stores a 3D model of the additional object to be displayed three-dimensionally in the 3D map;
A display control unit for displaying a three-dimensional map with reference to the projection image database and the additional object three-dimensional model database;
The display control unit
Pasting the projection image data on the ground surface in a virtual three-dimensional space,
Thereafter, the additional object 3D model is arranged in the virtual 3D space,
A three-dimensional map display system that displays the three-dimensional map by projecting the virtual three-dimensional space. The three-dimensional map display system according to claim 1,
By setting the position coordinates where the additional object is to be placed in an actual three-dimensional space, and converting the position coordinates under the projection conditions for generating the projection image data, the ground surface in the virtual three-dimensional space An additional object coordinate setting unit for generating the upper virtual position coordinates is provided,
The display control unit arranges the additional object based on the virtual position coordinates and a height component in the actual three-dimensional space, and displays the three-dimensional map. The three-dimensional map display system according to claim 1 or 2,
The projection for generating the projection image data is a three-dimensional map display system which is a parallel projection from an oblique direction inclined by a first projection angle with respect to the vertical direction. It is a three-dimensional map display system in any one of Claims 1-3,
The projection of the virtual three-dimensional space is a three-dimensional map display system that is a parallel projection from an oblique direction inclined by a second projection angle with respect to the vertical direction. A three-dimensional map display system according to any one of claims 1 to 4,
The additional object is a vehicle used in public transportation,
An additional object trajectory database for storing additional object trajectory data representing a movement trajectory of the additional object in an actual three-dimensional space;
The display control unit is a three-dimensional map display system that arranges the additional object and displays the three-dimensional map based on the additional object trajectory data. A three-dimensional map display method for displaying a three-dimensional map representing a feature three-dimensionally by a three-dimensional map display system having a computer,
The 3D map display system includes:
A projection image database for storing projection image data as two-dimensional image display data generated by projecting a feature under a predetermined projection condition;
In addition to the feature, an additional object three-dimensional model database that stores a three-dimensional model of the additional object to be displayed three-dimensionally in the three-dimensional map,
The 3D map display method includes:
As the steps executed by the computer,
Pasting the projection image data on the ground surface in a virtual three-dimensional space;
Thereafter, placing the additional object three-dimensional model in the virtual three-dimensional space;
A three-dimensional map display method comprising: displaying the three-dimensional map by projecting the virtual three-dimensional space. A computer program for displaying a three-dimensional map representing a feature three-dimensionally by a three-dimensional map display system having a computer,
The 3D map display system includes:
A projection image database for storing projection image data as two-dimensional image display data generated by projecting a feature under a predetermined projection condition;
In addition to the feature, an additional object three-dimensional model database that stores a three-dimensional model of the additional object to be displayed three-dimensionally in the three-dimensional map,
The computer program is
A function of pasting the projection image data on the ground surface in a virtual three-dimensional space;
A function for arranging the additional object three-dimensional model in the virtual three-dimensional space;
A computer program that causes the computer to realize a function of displaying the three-dimensional map by projecting the virtual three-dimensional space.