JPH10187029A - Three dimensional cg map display device, and on-vehicle navigation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to display a view realistically, by generating a three-dimensional CG road map viewed from an arbitrary view point based on altitude data and displaying it on a display. SOLUTION: In response to a control signal given from a controller 17, a memory drive 13 reads a fixed range of link from disk D1 including a current vehicle position or road map data expressed by nodes and altitude map data defined for every subdivided district beforehand, and outputs them to the controller 17. The controller 17 makes the road map data and altitude map data stored in a main memory. In the case of a three dimensional CG display, the geographical features information polygon is made based on the altitude map data and supplied to a graphic generator 24. The graphic generator 24 generates a three- dimensional image by three-dimensional computer graphic processing and makes it display on a display device 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional CG map display device for displaying a three-dimensional map from an arbitrary viewpoint using at least road map data and elevation data including a road represented by a link or a node. A three-dimensional CG map display device for creating and displaying a moving image of a road when a vehicle is simulated along a route, and creates a three-dimensional CG map viewing a road map from a viewpoint associated with a traveling vehicle. The present invention relates to an in-vehicle navigation device to be displayed, and an in-vehicle navigation device to create and display a moving image of a road when a vehicle is simulated for confirmation along a shortest route.

[0002]

2. Description of the Related Art Conventionally, an on-vehicle navigation device has been used to assist a vehicle traveling on unfamiliar land. In-vehicle navigation devices include direction sensors, distance sensors, GPS
It has a receiver, a road map memory including at least a road represented by a link or a node, a display device, a computer, and the like, and has azimuth data input from an azimuth sensor, mileage data input from a distance sensor, and GPS reception. It has a function to detect the vehicle position based on the position data input from the machine.

[0003] Such a navigation device may be provided with a route calculation function for automatically calculating the route from the current position of the vehicle to the destination by a computer in accordance with the input of the destination setting by the passenger. . If this function is used, it is possible to reliably reach the destination by traveling along the calculated route without knowing the road to the destination.

[0004] Road map software for personal computers is also known. With this road map software, you can search for maps using place names, station names, and facility names,
The shortest route between two points can be automatically searched. However, the map displayed on the screen of the in-vehicle navigation device or the screen of the personal computer described above is the road map data itself viewed from directly above, and it is possible to view the front screen which can be viewed from the inside of the vehicle window by simply viewing this on the screen. Is difficult to match.

Therefore, a technique has been developed for displaying a road map image as a bird's-eye view in a pseudo three-dimensional manner (see Japanese Patent Application Laid-Open No. Hei 7-220055). However, this technique is a pseudo three-dimensional display in which a road map is displayed as it is by changing the viewpoint and considering only perspective, and the original road map is not treated as three-dimensional data. Therefore, there is no concept of polygons, and the landscape including the road does not look three-dimensional.

On the other hand, using a three-dimensional CG (computer graphics) technique, based on shape data in which a three-dimensional shape of a building, a mountain, or the like existing on a map is stored, a desired direction from a desired point on the map is determined. The prior art for creating and displaying an image of a landscape when viewing a scene has been proposed (Japanese Patent Laid-Open No. 5-2 / 1993).
03457). According to this prior art, a three-dimensional shape is obtained based on shape data, and a landscape in a predetermined direction viewed from a predetermined position is subjected to processing such as hidden surface processing and shading using three-dimensional CG technology. Can be created.

However, according to the prior art described in Japanese Patent Application Laid-Open No. 5-203457, since all contour coordinates and vertex coordinates of the ground, mountains, buildings, and the like are stored in a database from the beginning, accurate polygons cannot be obtained. While it can be created, it requires enormous storage capacity. Further, the road is not always discriminated and displayed. On the other hand, traveling simulators using road map data and three-dimensional CG technology have been developed. This traveling simulator displays an animation of the road and the scenery that can be seen from the vehicle window when an arbitrary road in the whole country is designated (see Japanese Patent Application Laid-Open No. 6-83937).

The traveling simulator utilizes road data used in a navigation device, and generates other landscape polygons automatically by patterning and type designation or by using random numbers. Therefore, although the capacity of the memory is reduced, a scene different from the actual scene is displayed, which is not suitable for the purpose of guiding the driver. Therefore, the present invention displays roads, landscapes, buildings, and the like included in the road map based on elevation data defined for each of the subdivided areas as a landscape that matches reality without losing their images. It is an object of the present invention to realize a three-dimensional CG map display device and an in-vehicle navigation device that can perform the operation.

[0009]

[Means for Solving the Problems]

(1) The three-dimensional CG map display device according to the present invention is based on at least road map data including a road represented by a link or a node, elevation data defined for each subdivided area, and the elevation data. A three-dimensional CG map creating means for creating a three-dimensional CG map viewing the road map from the viewpoint of the above, and display control means for displaying the three-dimensional CG map created by the three-dimensional CG map creating means on a display device. (Claim 1).

Here, the “viewpoint” when “viewing the road map from an arbitrary viewpoint” may or may not change over time. In the former case, the three-dimensional CG map image is a moving image, and in the latter case, it is a still image. According to the three-dimensional CG map display device of the present invention, since the elevation data defined for each subdivided area is provided separately from the road map, each of the links and nodes constituting the road map is different from the conventional one. The number of altitude data can be set freely as compared with the case of having altitude data. That is,
If the “subdivided area” is set relatively coarse, the number of elevation data is small, but in this case, the texture of the three-dimensional CG map is coarse. If the “subdivided area” is set relatively fine, the number of elevation data will increase, but fine 3D CG
You can map. Therefore, the “subdivided area” can be set irrespective of the number of links and nodes constituting the road map, in consideration of both.

Then, based on the altitude data defined for each area, it is possible to create a three-dimensional CG map that looks at the road map from an arbitrary viewpoint. Such a three-dimensional CG map display device can be applied to a running simulator for simulating a vehicle along a route and an in-vehicle navigation device. (2) Creation of a three-dimensional CG map can be divided into a step of reading elevation data to create a terrain information polygon, and a step of reading road map data to create a facility information polygon and combining it with the terrain information polygon. (Claim 2).

Since the road map data and the altitude data are stored separately, it is reasonable to divide them into two-stage processes. In this way, three-dimensional CG as a moving image
When creating a map, it is also possible to create terrain information polygons in a relatively large creation area, read road map data frequently in a relatively narrow creation area, and create facility information polygons each time. In this specification, the “facility information polygon” is a generic name for building information polygons and road information polygons.

(3) It is desirable that the unit section for creating the terrain information polygon becomes coarser as the distance from the viewpoint position increases. In a three-dimensional CG screen, it becomes harder to recognize as the distance increases, so that a detailed screen is not required. Therefore, by making the unit section for creating the terrain information polygon coarser as the distance increases, the total number of polygons can be reduced and the processing time can be reduced.

(4) The creation area for creating a three-dimensional CG map has a sector shape in the bird's-eye view direction from the viewpoint position, divides the opening angle θ of the sector into small angles dθ, and generates elevation data for each dθ and for each unit section dr. It reads, it is preferable to divide the polygon at the position r _p their elevation data takes a maximum or minimum (claim 4). Since the position between the positions where the altitude data takes the maximum or the minimum is approximated by the plane of the polygon, the total number of polygons can be reduced and the processing time can be shortened.

(5) It is preferable that attribute data of the terrain is stored in association with the elevation data, the polygon is divided at a position where the attribute data changes, and a display mode is changed for each divided terrain information polygon. 5). Where the attribute data changes is, for example, a boundary of color classification in the case of display. Therefore, if the polygon is divided here and the display mode is changed, identification can be easily performed.

(6) The three-dimensional CG map display device of the present invention comprises:
Road map data including at least roads represented by links or nodes, and elevations defined for each subdivided area, used to create and display a moving image of the road when simulating a vehicle along a route. When a simulated traveling along a route is performed along with the data, a series of three-dimensional CG maps is created based on the elevation data stored in the map memory and a road map is viewed from a viewpoint associated with the simulated traveling vehicle. It has a three-dimensional CG map creating means and a display control means for displaying the three-dimensional CG map created by the three-dimensional CG map creating means on a display device.

The three-dimensional CG map display device is as follows.
The three-dimensional CG map display described above is applied to a traveling simulation device. (7) The three-dimensional CG map display device uses a route network database based on nodes or links to determine the shortest route from a current position or a manually set departure point and a manually set destination. Is further recorded, and the route on which the vehicle simulates traveling may be the shortest route calculated by the route calculating device (claim 7).

With this configuration, a three-dimensional CG map can be displayed when performing a running simulation along the shortest route. (8) The in-vehicle navigation device of the present invention is a map memory that stores at least road map data including a road represented by a link or a node and elevation data defined for each subdivided area, and is stored in the map memory. A three-dimensional CG map creating means for creating a three-dimensional CG map that looks at a road map from a viewpoint associated with a traveling vehicle based on the elevation data, and a three-dimensional CG map created by the three-dimensional CG map creating means. And a display control means for displaying on the display device (claim 8).

[0019] The three-dimensional CG map display according to the first aspect can be realized while traveling with an on-vehicle navigation device. (9) The in-vehicle navigation device according to the present invention includes a map memory storing at least road map data including a road represented by a link or a node and elevation data defined for each subdivided area, and stored in the map memory. Using a three-dimensional CG map creating means for creating a three-dimensional CG map looking at a road map from a viewpoint associated with a traveling vehicle based on the elevation data, and a route network database based on nodes or links, A route calculation means for calculating a shortest route from the current position or a manually set departure point and a manually set destination, and a mode in which a vehicle is simulated for confirmation along the calculated shortest route. A series of three-dimensional views of a road map viewed from a viewpoint associated with a simulated vehicle based on elevation data stored in the map memory. There is provided a three-dimensional CG map creating means for creating a CG map, and display control means for displaying a three-dimensional CG map created by the three-dimensional CG map creating means on a display device (claim 9).

When a running simulation along the shortest route is performed by the in-vehicle navigation device, a three-dimensional CG map can be displayed.

[0021]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. <Embodiment 1> In this embodiment, in a vehicle-mounted navigation device, a three-dimensional image is created based on road map data including at least a road represented by a link or a node and altitude map data stored in a memory, and vehicle-mounted navigation is performed. The present invention relates to a device for displaying an image on a display device of the device.

FIG. 1 is a block diagram of an on-vehicle navigation device. This device includes a distance sensor 11 for detecting a traveling distance of the vehicle and a sensor for detecting whether the vehicle is moving forward or backward. A shift sensor 13 is provided. These two sensors 11, 13
Is output to the locator 15. A gyro sensor 16 for detecting a turning angle of the vehicle is provided, and a detection output of the gyro sensor 16 is also provided to the locator 15.

The locator 15 is further connected to a receiver 27 as external information acquisition means. Receiver 27
Is for receiving data such as position information and road information (congestion information, accident information, intersection names, and destination guidance) radiated from the information providing means. The information provision means
In the case of a beacon antenna installed on the road side of a road or the like, it is preferable that the installation interval of the beacon antenna is shorter, because detailed road information can be obtained. It is ideal that the service areas of the beacon antennas are densely installed so as to overlap each other (continuous beacons). Also,
The information providing means may be a leaky coaxial cable laid parallel to the road other than the beacon antenna. In this case, the receiver 27 is a receiver that receives a radio wave from the leaky coaxial cable. Further, the information providing means may be an FM multiplex broadcaster, a communication satellite, or a broadcast satellite. In this case, the receiver 27 is an FM multiplex receiver, a communication satellite radio receiver, or a broadcast satellite radio receiver.

The data received by the receiver 27 is provided to the controller 17 and is finally displayed on the display device 22 to convey information to the driver. A GPS receiver 29 is connected to the locator 15 as an optional device. When the GPS receiver 29 is provided, a signal from a GPS satellite is received, and an absolute position and an azimuth can be accurately detected, or a current position of a moving object can be directly detected.

The locator 15 is used to calculate the current position of the vehicle. The locator 15 calculates the azimuth change amount of the vehicle based on the turning angle of the vehicle detected by the gyro sensor 16.
The shift sensor 13 is added to the distance detected by the distance sensor 11.
The moving distance of the vehicle is determined in consideration of the forward or backward movement of the vehicle given by the vehicle. Therefore, for example, if accurate initial position data of the vehicle is provided to the locator 15 before the vehicle starts moving, the locator 15 calculates the current position of the vehicle thereafter.

The locator 15 compares the travel locus data with the road pattern stored in the disk D1 (so-called map matching method;
On the basis of the existence probability of the vehicle, and a function of detecting the position of the vehicle on the road. Data representing the current position of the vehicle calculated by the map matching method is provided to a controller 17 which is a control center of the vehicle-mounted navigation device. The controller 17 includes a CPU, a ROM, a RAM, and the like,
The graphic generator 24 and the TF are connected to the locator 15 and the memory drive 18 described above.
It is connected to a display device 22 using a T liquid crystal, STN liquid crystal or the like, a remote control switch 23, and a voice guidance device 25.

The remote controller switch 23 specifies whether to display a three-dimensional CG or a normal two-dimensional map, and specifies various constants (specification of a target attribute of the terrain information). , Levitation position designation, levitation overhead view designation, landmark designation, terrain information display range designation, polygon creation constant designation).
The controller 17 controls the memory drive 18 based on the current position data of the vehicle calculated by the locator 15. The memory drive 18 reads path calculation link data for path calculation from the loaded disk D1 in response to a control signal given from the controller 17, and outputs the link data to the controller 17. Controller 1
7 calculates the shortest route from the current position to the destination and displays the obtained shortest route (for a route calculation method, see, for example, Japanese Patent Application Laid-Open No. 58-223017).

The disk D1 is a CD-ROM, DVD
(Digital Versatile Disk)-constituted by a large-capacity storage medium such as a ROM, a hard disk, a floppy disk, and an IC card. Further, the memory drive 18 reads road map data and altitude map data of a predetermined range including the current position of the vehicle from the disk D1 in advance in response to a control signal given from the controller 17, and outputs the data to the controller 17.

The controller 17 stores the road map data and the elevation map data of the predetermined range in the main memory 34 (see FIG. 5), and the remote controller 23 designates a three-dimensional CG display or a normal two-dimensional display. Different processing is performed depending on the map display. In the case of a normal two-dimensional map display, predetermined image data is created based on the current position data calculated by the locator 15 and the road map data stored in the main memory 34, and the current position of the vehicle is displayed together with the road map. Is displayed on the display device 22 by a method usually used.

In the case of the three-dimensional CG display, a terrain information polygon is created based on the elevation map data, and a facility information polygon corresponding to the terrain is created and given to the graphic generator 24. Graphic generator 24
Performs a three-dimensional computer graphics process to create a three-dimensional image, supplies the three-dimensional image to the display device 22, and displays the three-dimensional image (the three-dimensional computer graphics technology itself is a known technology. See JP-A-5-203457).

The road map data is created from a nationwide map database, and meshes a road map (including highway expressways, motorways, national roads, prefectural roads, city roads of designated cities, and other living roads). And stores data composed of combinations of nodes and links in units of each mesh (hereinafter referred to as “map mesh”). Here, a node is generally a coordinate point for specifying a road intersection, a road bending point (referred to as an interpolation point), a boundary point of a map mesh, a dead end point, and the like. A link is a directed line segment connecting each node.

The road map data also stores data for displaying railroads, stations, famous building names, street names, parking lots, parks, rivers, and the like for map display. FIG.
Is a diagram showing a specific example of a road map. Further, the road map data stores the building number and the building position along the link. The building number is a number for searching for a three-dimensionally displayed building by performing the building information polygon creation processing. This number is given for each type of building.

In this embodiment, the "type of building" is classified according to a relatively higher concept. For example, any bank treats any bank as one type of bank. Therefore, the type of building is stored as 0: police box, 1: gas station, 2: hospital, 3: restaurant, 4: bank, 5: post office, -1: none. However, it is also possible to categorize by lower concepts. For example, in the case of a bank, classification may be performed for each unique name such as “Tokyo Mitsubishi Bank” and “Sakura Bank”. If a classification is made for each unique name, the patterns and colors attached to the polygons will also be diversified, and the amount of information provided to the driver can be increased. In this embodiment, the building is limited to the building existing on the left side of the road. However, buildings existing on both sides of the road may be targeted.

Using this building number, a building management file that stores colors and patterns to be displayed on the wall surface of the building and vertex coordinates of a polyhedron (polygon) forming the building is searched, and the shape and pattern of the building are searched. Color can be specified.
The building position indicates the position where the building exists by the distance from the starting point of the link. Although the building number and the building position may be stored only for one link corresponding to one building, it is preferable that a plurality (up to N) can be stored in practice. In this way, a plurality of buildings can be displayed in association with one link, and a real screen with a larger amount of information can be created. The maximum number N is a number determined in consideration of the capacity of the map-dedicated disk D1.

The elevation map data is obtained by dividing the map mesh into areas, and storing elevation data and attribute data (water areas, residential areas, open areas, forests, mountains, and the like represented by numbers) for each area. Table 1 shows an example of this storage structure.

[0036]

[Table 1]

In Table 1, the map mesh is divided vertically (north-south) m and horizontally (east-west) n, and elevation data and attribute data are stored for each divided area. The size of the area is 50 m square, 250 m square, 1 km square, and the like.
There is no limitation on the storage location of the elevation map data in the map-dedicated disk D1, and the elevation map data may be stored separately from the road map data, or may be stored in the same area where the map mesh is common. Is also good.

FIG. 3 specifically shows this elevation map data in a diagram. In FIG. 3, the map mesh is vertically 5,
The area is divided into 10 sections, and the elevation (unit m) and attributes (open space, mountain) of each area are described. FIG. 4 is a diagram three-dimensionally displayed based on the elevation map data. In FIG. 4, "vacant land"
Is indicated by an oblique line rising to the right, and “mountain” is indicated by an oblique line rising to the left.

FIG. 5 is a functional block diagram of the inside of the controller 17.
8, a map data management unit 31 that reads road map data and elevation map data in a predetermined range, an input processing unit 32 that converts the operation of the remote control switch 23 into a signal, destination information input from the remote control switch 23, and route calculation. It has a route calculation processing unit 33 that calculates the shortest route to the destination using the link data for use, a main memory 34, a three-dimensional CG creation processing unit 35, and a route guidance processing unit 36.

The three-dimensional CG creation processing unit 35 is a part for performing an image creation process. Based on the read road map data and the elevation map data, the three-dimensional CG creation processing unit 35 is a three-dimensional CG viewed from inside or outside the running vehicle. Create image data. A three-dimensional image created by performing three-dimensional computer graphics processing based on this image data is referred to as a “3D display screen”.

Further, according to the flowchart (FIG. 6),
The function of the three-dimensional CG creation processing unit 35 will be described in detail. The user designates three-dimensional CG display or normal two-dimensional map display by the remote control switch 23, inputs various constants, for example, designates an attribute to be subjected to terrain information, designates a bird's-eye position and posture, designates a bird's-eye position, A bird's-eye view posture, a terrain information display range, and a polygon creation constant are specified (step S1).

The three-dimensional CG creation processing unit 35 refers to the moving distance and azimuth of the vehicle (step S2), and creates a terrain information polygon (step S4) every time the vehicle moves a fixed distance (step S3). Creation of information polygon (step S5) and creation of building information polygon (step S5)
Perform 6). Each time an information polygon is newly created, old information polygons left behind after the vehicle has passed are deleted from the main memory 34.

In the flowchart, the creation of each information polygon is continuously performed. First, the terrain information polygon over the terrain information display range is performed at a relatively long cycle.
It is also conceivable that the generation of the road information polygon and the building information polygon in a smaller area is frequently performed at relatively short intervals. This is because the road information polygon and the building information polygon usually have a larger amount of information processing.

In the flowchart, each information polygon is created each time the vehicle travels a predetermined distance. Alternatively, each information polygon may be created when the vehicle stops at a traffic light or the like. The position at which the polygon is created may be determined in advance, and the operation may be performed when the position is reached. Then, the three-dimensional CG display and the normal two-
It is determined which of the two-dimensional map displays has been designated (step S7). If the three-dimensional CG display is designated, the three-dimensional CG viewed from the bird's-eye view position is referred to by referring to the terrain information polygon data and the road information polygon data (step S11).
Processing is performed to create a 3D display screen (step S1
2).

When the 3D display process is performed, all the road information polygon data created may be processed, or a certain range just ahead of the vehicle may be processed. The reason for targeting a certain range is that it takes time to add 3D image information of roads and buildings to all display ranges, so it is necessary to limit the target,
Even if a small road or building reflected in the distance is made three-dimensional, it is hardly visible to the driver.

If two-dimensional map display is designated, a road map centering on the current position of the vehicle is created with reference to the road map data (step S8). Then, it is determined whether the current position or the traveling link of the vehicle is a target of the 3CG automatic display (step S9), and if it is, the process proceeds to the step S11.

Here, in the case of a system in consideration of the driver's safety, whether or not it is an object of 3CG automatic display is determined as follows.
For example, the determination criterion may be based on whether (a) the road changes in the type or physical shape of the road, or (b) the road changes the content of the road traffic regulation. In the case of a system in which the operability of the driver is taken into consideration, the display may be made in accordance with the driver's specification, or may be displayed occasionally so as not to get tired when traveling on a highway for a long time.

In the case of a system in which the safety of the driver is taken into consideration, when the vehicle is traveling on the road, the type of road (the distinction between highway motorways, motorways, and national roads) and the physical shape (road width) Roads that the driver pays particular attention to due to changes in traffic, roads, hills, prospects, etc.) or changes in traffic regulation on the roads. For example, roads that have climbed up a hill (pass), roads with narrow roads, roads with tunnel entrances, roads with sharp curves, roads that lead to intersections where five or more roads meet, roads with railroad crossings, Roads where regulation speeds change, roads with statistically many accidents, and sightseeing roads can be cited.

If these roads are in front of the road, it is difficult for the driver to see them. Therefore, it is not possible to grasp the degree of the downhill slope, the necessity of changing lanes, the depth of the curve, etc. Because there is. For these roads, the creator of the road map data may conduct a field survey in advance and enter the information into the road map data. Alternatively, the user may subjectively determine and manually input.

If not, a road map is displayed together with a vehicle mark (step S10). next,
The terrain information polygon creation processing (step S4) will be described. FIG. 7 shows a coordinate system in which the X axis and the Y axis are set on a horizontal plane and the Z axis is set vertically. Taking overhead located at a point in the Z-axis height above h _0. The bird's-eye view position is used to determine from what point of view the display data is created, and can be set arbitrarily, such as the height of the driver's eyes sitting in the vehicle seat or a certain height above the vehicle. can do. If you set it above the sky, you can intuitively grasp the road conditions ahead.

Then, the fan-shaped terrain information display range is set on the horizontal plane in the bird's-eye view direction. The azimuth range of the terrain information display range is from θ _min to θ _max , and the maximum distance is r _max
And Further, the unit section of the direction is dθ, and the unit section of the distance is dr. FIG. 8 shows that the azimuth θ + d
FIG. 7 is a diagram in which a terrain information display range up to θ is drawn on an elevation map. The unit section dr of the distance is set to be the size of the divided area.

In the above description, the unit section dr is always constant (see FIG. 9A), but dr may be changed greatly as the distance r from the origin increases. FIG.
FIG. 9B to FIG. 9C are diagrams showing examples in which dr is changed. FIG. 9 (b) shows that dr is 1 time, 2 times,
Fig. 9 (c) shows an example of three times and ‥‥.
Shown below is an example of quadruple and ‥‥. As described above, if dr increases as the distance increases, the total number of polygons can be reduced and the processing time can be reduced.

In the above description, the azimuth unit section d
Although θ has always been constant, dθ may be increased as the distance r from the origin increases. FIG. 9D shows an example in which dr is set to 1, 2, 3, or ‥‥ the size of the divided area, and dθ is doubled at the point where dr = 3 changes to dr = 4. . The three-dimensional CG creation processing unit 35 sets the distance r to 0
From varied to r _max elevation data string h _{i (i} = 1,2,3,
‥‥). FIGS. 10 and 11 show this elevation data sequence in a bar graph form.

The graph of FIG. 10, the minimum value of the altitude data sequence h _i, is obtained by displaying the maximum value in the hatched, the graph of FIG. 11, the change point of the attributes of elevation data sequence h _i (the mountain glade (Change point) is indicated by oblique lines. FIG.
The minimum value of the altitude data sequence h _i from the point of view, represents the line of sight when viewed the changing point of maximum values and attributes by a two-dot chain line, the minimum value, maximum value (collectively hereinafter referred to as "extreme") and attributes FIG. 5 is a diagram in which, of the line segments connecting the changing points of the line, those visible from the line of sight are represented by thick lines, and those not visible from the line of sight are represented by broken lines.

Assuming that the distance between the extreme point and the change point of the attribute from the origin is r _p (p = 1, 2, ‥‥), the point (r _1, θ,
h ₁ ), point (r _1, θ + dθ, h ₁ ) and bird's-eye view position (0, 0, h ₀ )
The door as the vertex of the triangle, as well as create a polygon of triangle, point _{(r p, θ, h p} ), point _{(r p, θ + dθ,} h
_p ), point (r _{p + 1,} θ, h _{p + 1} ), point (r _{p + 1,} θ + dθ, h
Create a quadrilateral polygon with _{p + 1} ) as the vertex of the quadrilateral.

FIG. 13 is a perspective view showing the created polygon. Hatched polygons indicate open spaces, and filled polygons indicate mountains. In the above example, the extremal value and the change point of the attribute are obtained, but a polygon may be created for each dr without considering the extremal value and the change point of the attribute. In this way, a finer terrain information polygon can be created.

As described above, from the azimuth θ to θ + dθ
When you create a polygon for terrain information, the range is from θ + dθ
The same processing is performed after shifting to θ + 2dθ. FIG.
Topographic information display range from position θ + dθ to azimuth θ + 2dθ
It is the figure which drew on the elevation map. Distance r from 0 to r
_maxTo the elevation data string h_i(i = 1,2,3, ‥‥)
Is a bar graph along the θ + dθ direction.
Fifteen. Elevation data string h _iThe extreme values of
I have.

[0058] Figure 16 is a minimum value of the altitude data sequence h _i of θ + 2dθ direction from the viewpoint represents the line of sight when viewed the changing point of maximum values and attributes by a two-dot chain line, the minimum value, the change in maximum values and attributes FIG. 3 is a diagram showing, among the line segments connecting points, those visible from the line of sight by thick lines, and those not visible by the line of sight by broken lines.
FIG. 17 is a diagram showing polygons created in the range from the orientation θ + dθ to θ + 2dθ. In create these polygons, the minimum value of the altitude data sequence h _i of theta + d [theta] direction shown in FIG. 12, a change point of maximum and the attribute "open space 50, open areas 70, open areas 50, Mountain 70, mountain 80 "
And (numerals represent elevation), the minimum value of the altitude data sequence h _i of θ + 2dθ direction shown in FIG. 16, a change point of maximum and the attribute "open space 50, open areas 70, open areas 50, Mountain 80, mountain 90 "create a rectangle of polygon as vertex, respectively, when the height is different at the same distance r _p is divided into triangles.

FIG. 18 is a perspective view showing the polygon thus created together with the elevation, and FIG. 19 is a perspective view showing only the polygon. 18 and 19, the azimuth θ
And a polygon created in the range from θ + dθ to θ + dθ (the same as in FIG. 13) and a polygon created in the range from azimuth θ + dθ to θ + 2dθ. In FIGS. 18 and 19, the distinction of the display for each attribute is omitted.

When creating a polygon, a polygon in which all vertices are blind spots when viewed from the viewpoint (FIG. 1)
8, a method shown in FIG. 19 with a broken line) may not be created or may not be displayed even if created. This is because it is not necessary to display the image because it cannot be seen from the viewpoint, and the processing speed is reduced. When the processing is completed for the azimuth range from θ _min to θ _max in this manner, a polygon of the terrain information for the entire terrain information display range is completed.

Next, the process of creating a road information polygon (step S5) will be described. First, referring to the road map data in the terrain information display range, the links in the data are sequentially extracted. Then, roughly, two processes of a road creation process and a three-dimensional road process are performed.

The road creation process itself is known (see Japanese Patent Application Laid-Open No. 6-83937). The link width W of each link is obtained with reference to the road map data, and a road shape having the road width W on a plane is created based on the road width W. FIG. 20 shows an intersection-shaped road having a road width W created on a plane. When the link width W is not stored in the road map data, the road width W may be a fixed width. When the link width W can be set by the remote control switch 23, the road width W may be the set width. It may be. Further, a sidewalk having a certain width may be provided, or a centerline and a crosswalk may be provided.

In setting the road width, there is a case where the links are bent and connected at the interpolation point. In this case, a process for smoothly connecting the links may be performed. When links having different road widths are connected, the road width may be changed to a tapered shape. Regarding the processing of the corner at the intersection, the corner may be reduced and expressed by a circular curve, and the corner of the sidewalk may be processed at an obtuse angle.

FIGS. 21 to 23 are diagrams for explaining the three-dimensional road processing. In FIG. 21, a perpendicular line is drawn from each corner of a road or an intersection, and an intersection (indicated by a black circle) with the terrain information polygon is obtained. Further, in FIG. 22, an intersection on the line where the terrain information polygons intersect (indicated by a white circle)
Ask for.

Then, as shown in FIG. 23, the obtained intersections are connected to create a road information polygon suitable for the terrain.
Finally, a building information polygon creation process (step S6)
Will be described. The building information polygon is created on the terrain information polygon similarly to the road information polygon, and the order in which the building information polygon and the road information polygon are created does not matter. The building information polygon and the road information polygon are collectively referred to as “facility information polygon”.

FIGS. 24 to 27 are diagrams for explaining the building information polygon creating process. FIG. 24 is a diagram illustrating a state in which the building management file is searched, the installation position, the shape, and the like of the building are specified, and the building management file is placed on a horizontal plane. Next, as shown in FIG. 25, a perpendicular line is set up from each vertex of the bottom surface, and a point that hits the terrain information polygon is determined. And as shown in FIG.
The building is slid upward by the height of the lowest point (the back right point) of the bumped points.

Then, as shown in FIG. 27, the part hidden under the terrain information polygon is erased to complete the building information polygon. In this way, each building is placed on the terrain information polygon by the height thereof, and a three-dimensional realistic image can be created. Then, the facility information polygon is subjected to three-dimensional CG processing and displayed on the screen. At this time, the terrain information is preferably displayed in different colors according to the contents of the attribute data (for example, water area: light blue, residential area:
Gray, open space: yellow-green, forest: green, mountain: brown, etc.). It is preferable that the facility information is also displayed in different colors as appropriate. Also,
As the distance increases, the color density may be lighter or whitish. In this way, the image becomes more blurred as the distance increases, and a more realistic feeling can be obtained. Also, as described with reference to FIGS. 9B, 9C, and 9D, when the size of the divided area is increased as the distance r increases, the connection between polygons becomes unnatural by blurring. Can be made inconspicuous.

In this manner, the bird's-eye view position changes each time the vehicle travels, and the 3D display screen corresponding to the new viewpoint position is displayed each time the vehicle travels. It looks like a moving image viewed from the position. Note that various methods can be considered as a display method of the 3D display screen. For example, a small window is provided in a screen in which the position of the vehicle specified by the locator 15 is superimposed and displayed on the road map screen based on the road map data, and the 3D display screen of the changing road is displayed therein. May be displayed. Further, when displaying the 3D display screen, the display of the road map screen may be stopped and the 3D display screen may be enlarged. Further, when displaying the 3D display screen, the 3D display screen may be enlarged and the road map screen may be displayed in the window.

Further, a projector is placed on the dashboard together with or instead of the display device 22, and the
The D display screen may be projected on the front window. In this way, the driver can see the image reflected from the front window, so that the driver does not look away from the front, which is advantageous for safety. When projecting onto the front window, the reflectivity of the front window is usually low, so it is preferable to repeatedly perform flash display that instantaneously emits strong light.

As described above, when the changing road is ahead, by displaying it three-dimensionally, it is possible to further help the driver's attention and guidance. In addition,
When alerting the driver with a 3D display screen,
If an image is displayed and voice is simultaneously output by the voice guidance device 25, more reliable and safe guidance can be performed.

As described above, the data capacity required when creating the terrain information polygons and the facility information polygons matching the terrain, and the buildings, mountains, etc. existing on the map as in the prior art. Is compared with the data capacity required when the three-dimensional shape is stored. The size of one map mesh of a road map is 10 km × 10 km, and the number of links existing in the mesh is 14,000.

The size of the divided area according to the present invention is 50 m.
Trial calculations are made for the cases of × 50 m, 250 m × 250 m, and 1 km × 1 km. (1) In the case of the prior art The building and the ground are ignored and they are within one map mesh
It is assumed that three-dimensional coordinate values are stored for four vertices of 14,000 roads.

One coordinate value is composed of three numerical values of orthogonal coordinates X, Y and Z. If each requires 2 bytes of storage, then 2 x 3 = 6 bytes per coordinate,
One road has 6 × 4 = 24 bytes and 14,000 roads, so a total storage capacity of 24 × 14,000 = 336,000 bytes is required. (2) In the case of a 50 m × 50 m area Assume that two-dimensional coordinate values are stored for each of two nodes of 14,000 roads in one map mesh, and two bytes of elevation data are stored for each area.

The node coordinates are composed of two numerical values of X and Y. If you need 2 bytes of storage each,
2 × 2 = 4 bytes for one node coordinate, 4 × 2 = 8 bytes because one link is composed of the start and end nodes, and since there are 14,000 such links, the total is 8 × 14,000 = 112,000 bytes. In addition, the elevation data indicates that the number of areas is (10 km ÷ 5
0m) ² = 40,000, so 2 bytes x 40,000 = 80,0
00 bytes.

A total storage capacity of 192,000 bytes is required. (3) In the case of a 250m x 250m area The elevation data is based on the number of areas (10km / 250m) ² = 1,
Since there are 600, 2 bytes x 1,600 = 3,200 bytes. A total of 115,200 bytes of storage is required.

(4) In the case of a 1 km × 1 km area The elevation data is such that the number of areas is (10 km ÷ 1 km) ² = 10
Since there are 0, 2 bytes × 100 = 200 bytes. A total of 112,000 bytes of storage is required. From the above, the size of the divided area is 50m × 50m, 25
In any case of 0m × 250m, 1km × 1km,
The storage capacity of the disk D1 becomes smaller. This is because, in the present invention, since the road map data is stored as two-dimensional data instead of three-dimensional data, the number of coordinates is reduced by one. In the present invention, it is necessary to store elevation data instead. However, one map mesh is divided into sections, and
Since one elevation data is stored as a representative, the number of data can be reduced, and the storage capacity is reduced as a whole as compared with the prior art.

In the above example, if a divided area of 250 m × 250 m is taken, the storage capacity of the disk D 1 is 115,200 mm.
That's 336,000, one-third. In practice, the area of 50m x 50m is too fine for trunk line, so 2
There is a high possibility that an area of 50 m x 250 m will be adopted. In the above comparison, the prior art ignored the existence of the ground. Therefore, since only the road rises and is unnatural, if the surface of the road and the ground are to be brought together as in the present invention, the prior art also requires a polygon of the ground. That is, in the prior art, the storage capacity is increased many times more than in the comparative example.

In the prior art and the present invention, the existence of a building was neglected. However, if a building is to be represented by a polygon, the information of the base and the height is required in both the present invention and the prior art. However, since the amount of information becomes the same, it was deliberately excluded from comparison. <Embodiment 2> This embodiment is used by being loaded into a general-purpose personal computer, a computer game machine, or the like, and uses a route network database based on nodes or links to use a current position or a manually set departure place. A shortest route or a shortest distance route (hereinafter, referred to as a “shortest route”) from a manually set destination and a three-dimensional CG map display device for simulating a vehicle along the shortest route. is there.

The three-dimensional CG map display device may be constituted by any kind of medium, for example, CD-ROM, DVD
(Digital Versatile Disk)-A large-capacity storage medium such as a ROM or a magnetic tape can be used. These storage media store road map data and elevation map data having the same contents as in the first embodiment.

Next, assuming that a CD-ROM is used as a storage medium, flowcharts (FIGS. 28 and 29)
, The contents of the three-dimensional CG map display means will be described.
When the CD-ROM is mounted on the personal computer, the user sets various constants on the screen and specifies whether or not to display 3CG (step T1). The user
A road map screen is displayed to set a departure place or a current place and a destination (step T2). At this time, it goes without saying that one or a plurality of transit points may be set.

Then, the shortest route is searched (step T).
3) When the search is completed, a road map including the shortest route is displayed. The shortest route is displayed in a prominent form (step T4). Here, it is determined whether or not to display 3CG (Step T5). If NO, a two-dimensional running simulation of moving the vehicle mark along the shortest route on the road map is performed (Step T6). . If YES, a three-dimensional traveling route is determined from the shortest route (step T7). The “three-dimensional travel route” is a route that simulates a course with hills and valleys in which the shortest path is made three-dimensional.

Then, the bird's-eye view position E along this traveling route
_i (i = 1, 2, 3, ‥‥) is determined in advance (step T
8). Bird's-eye view position E _i may be taken to a certain height of the height and the vehicle of the sky in the eyes of the driver sitting on the seat of a vehicle. If you come to a certain position where the traveling position is related to the overhead position E _i or overhead position E _i of the vehicle, creating and storing terrain information polygon by setting the fan terrain information display range as viewed from overhead position E _i (Step T10).

The method of creating the terrain information polygon is the same as that described in the first embodiment. However, this embodiment is different from the first embodiment in that the terrain information polygons are collectively created before traveling. However, Embodiment 1
Similarly to the above, it may be created while traveling. By creating topographic information polygon for all the overhead position E _i (step T9), start simulated travel along the travel route (step T12). Then, referring to the road map (step T
13), determine the target range of 3CG display from the current position (step T14), and create a road information polygon (step T15).

The method of creating the road information polygon is the same as that described in the first embodiment. In this embodiment, the road information polygon is created while traveling, but may be created before traveling as a whole, like the terrain information polygon. Then, the terrain information polygon and the road information polygon are subjected to three-dimensional CG processing and displayed on the screen (step T16). At this time, it goes without saying that the polygons to be subjected to the three-dimensional CG processing may be limited. Then, each time the vehicle travels, the bird's-eye view position changes, and each time a 3D display screen corresponding to the new viewpoint position is created and displayed, the 3D display screen is a moving image viewed just from the bird's-eye view position. looks like.
In the above description, the case where the viewpoint is automatically moved along the shortest path calculated in advance has been described. However, the user manually moves the viewpoint to an arbitrary position using an input device such as a mouse, a joystick, and a keyboard. You may.

The second embodiment described above relates to a three-dimensional CG map display device for loading a personal computer or the like and performing a running simulation. However, this three-dimensional CG map display device is applied to an in-vehicle navigation device. It is also possible to perform a running simulation on the display screen of the in-vehicle navigation device. In this case, the in-vehicle navigation device is operated in a real driving mode (a mode in which a 3D display screen is created along the driving route while the vehicle is actually running) or a simulation mode (the vehicle is virtually driven at a predetermined speed). It is necessary to provide a selection means for selecting any one of the modes (a mode for creating a 3D display screen along the traveling route in the state).

[0086] The benefits of simulating the vehicle-mounted navigation device are as follows. That is, since the shortest route can be calculated even before the vehicle travels if the destination is set by the remote control switch 23, the display screen is also created before the vehicle travels based on the shortest route, and the image is quickly forwarded before the travel starts. Display on the screen. In this way, the driver can keep in mind how to drive the road on the shortest route before traveling.

[0087]

As described above, according to the first aspect of the present invention, at least the elevation data defined for each subdivided area is provided separately from the road map including the road represented by the link or the node. As compared with the case where the elevation data is provided for each link or node constituting the road map, the “subdivided area” can be set independently of the number of links or nodes constituting the road map.

Therefore, if the method of setting the “subdivided area” is made finer, a fine-grained three-dimensional CG map can be displayed, and if it is made coarser, the memory can be saved. According to the invention of claim 2, three-dimensional CG
The map is created in two stages: reading elevation data to create terrain information polygons, and reading road map data to create facility information polygons and combining them with terrain information polygons. When creating a three-dimensional CG map, it is possible to create terrain information polygons in a relatively large creation area, read road map data frequently in a relatively narrow creation area, and create facility information polygons each time. Be more efficient.

According to the third aspect of the invention, by making the unit section for creating the terrain information polygon coarser as the distance increases, the total number of polygons can be reduced and the processing time can be shortened. According to the invention described in claim 4,
Since the position between the positions where the altitude data takes the maximum or minimum is approximated by the plane of one polygon, the total number of polygons can be reduced and the processing time can be reduced.

According to the fifth aspect of the present invention, a portion where the attribute data changes is also a boundary for color classification when displayed, so if the polygon is divided here, the color classification process can be easily performed. According to the invention of claim 6, the three-dimensional CG map display of claim 1 can be performed at the time of traveling simulation.

According to the seventh aspect of the present invention, when performing a running simulation along the shortest route, the three-dimensional CG
A map can be displayed. According to the eighth aspect of the present invention, the three-dimensional CG map display of the first aspect can be realized by the on-vehicle navigation device while traveling. According to the ninth aspect of the present invention, it is possible to display the three-dimensional CG map according to the first aspect when performing a running simulation along the shortest route with the in-vehicle navigation device.

[Brief description of the drawings]

FIG. 1 is a block diagram of an in-vehicle navigation device.

FIG. 2 is a diagram showing a road map represented by a link or a node.

FIG. 3 is a specific example of elevation map data in which a map mesh is divided into 5 columns and 10 columns, and elevations (units m) and attributes (open areas, mountains) of each area are described.

FIG. 4 is a diagram in which terrain is displayed three-dimensionally based on elevation map data. "Open area" is indicated by a diagonal line that rises to the right,
"Mountains" are indicated by diagonally upwards diagonal lines.

FIG. 5 is a functional block diagram of a controller 17;

FIG. 6 is a flowchart illustrating a flow of a three-dimensional CG creation process.

FIG. 7 is a coordinate system for explaining a creation process of a terrain information polygon having an X axis and a Y axis on a horizontal plane and a Z axis vertically.

FIG. 8 is a diagram in which a terrain information display range from azimuth θ to θ + dθ is drawn on an elevation map.

FIG. 9 is a diagram illustrating an example in which a unit section for reading altitude data is made coarser as the distance from the viewpoint position increases, and FIG. 9A illustrates a case where the unit section dr is constant regardless of the distance r from the origin.
(b) shows that dr is one, two, three times, and ‥ the size of the divided area.
C, (c) is 1, 2, 4 times, 倍, (d), dr is 1, 2 times,
An example is shown in which the value of dθ is doubled at the point where dr = 3 and dr = 4 as well as triple and Δ.

[10] minimum value of the altitude data sequence h _i, is a graph displaying the maximum value by hatching.

11 is a graph displaying the change point of the attributes of elevation data sequence h _i (the point at which changes mountain glade) by hatching.

FIG. 12 shows a line of sight when the minimum value, the maximum value, and the change point of the attribute of the elevation data sequence are viewed from the viewpoint by a two-dot chain line, and the line segment connecting the change point of the extreme value and the attribute is seen from the line of sight. Are shown by bold lines, and those not visible from the line of sight are shown by broken lines.

FIG. 13 is a perspective view showing a terrain information polygon created between azimuth θ and θ + dθ.

FIG. 14 is a diagram in which a terrain information display range from an azimuth θ + dθ to an azimuth θ + 2dθ is drawn on an elevation map.

[15] minimum value of the altitude data sequence h _i, is a graph displaying the maximum value by hatching.

[16] elevation data column from the point of view θ + 2dθ direction h _i
The line of sight when the minimum value, the maximum value and the change point of the attribute are seen is represented by a two-dot chain line. Of the line segments connecting the minimum value, the maximum value and the change point of the attribute, those visible from the line of sight are represented by a bold line. FIG. 4 is a diagram in which an invisible object is indicated by a broken line.

FIG. 17 is a diagram showing polygons created in the range from azimuth θ + dθ to θ + 2dθ.

FIG. 18 is a perspective view showing a polygon created in the range from the azimuth θ to θ + dθ and a polygon created in the range from the azimuth θ + dθ to θ + 2dθ together with the elevation.

FIG. 19 is a perspective view showing only created polygons.

FIG. 20 is a perspective view showing an intersection-shaped road having a road width W created on a plane based on road map data.

FIG. 21 is a diagram illustrating a part of a three-dimensional road process in which a perpendicular line is formed from each corner of a road or an intersection and an intersection (indicated by a black circle) with a terrain information polygon is obtained.

FIG. 22 is a diagram illustrating a part of a three-dimensional road process for obtaining an intersection (indicated by a white circle) on a line at which the terrain information polygons intersect.

FIG. 23 is a completed diagram in which road information polygons that match the terrain are created by connecting the obtained intersections.

FIG. 24 is a diagram showing a state in which a building management file is searched to determine an installation position, a shape, and the like of a building, and the building is located on a horizontal plane.

FIG. 25 is a diagram showing a vertical line drawn from each vertex of the bottom surface, and finding a point that hits the topographical information polygon.

FIG. 26 is a diagram in which a building is slid upward by the height of a point having the lowest height (a point at the back right) among the points that have hit each other.

FIG. 27 is a diagram in which a part hidden under the terrain information polygon is deleted to complete the building information polygon.

FIG. 28 is a flowchart illustrating the contents of a three-dimensional CG map display unit when a vehicle is simulated along the shortest route.

FIG. 29 is a flowchart illustrating the contents of a three-dimensional CG map display unit when a vehicle is simulated along the shortest route (continuation of FIG. 28).

[Explanation of symbols]

 15 Locator 17 Controller 18 Memory drive 22 Display device 23 Remote control switch 24 Graphic generator 31 Map data management unit 32 Input processing unit 33 Route calculation processing unit 34 Main memory 35 3D CG creation processing unit 36 Route guidance processing unit D1 Disk

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G08G 1/0969 G06F 15/62 360

Claims (9)

[Claims] A road map is viewed from an arbitrary viewpoint based on road map data including at least a road represented by a link or a node, elevation data defined for each subdivided area, and the elevation data. A three-dimensional CG map display device having three-dimensional CG map creation means for creating a three-dimensional CG map, and display control means for displaying the three-dimensional CG map created by the three-dimensional CG map creation means on a display device. 2. The three-dimensional CG map creating means reads out elevation data to create terrain information polygons, and reads out road map data to create facility information polygons.
3. The three-dimensional CG map display device according to claim 1, wherein the three-dimensional CG map display device is divided into a means for combining with a terrain information polygon. 3. A unit section for creating a terrain information polygon is:
2. The three-dimensional CG map display device according to claim 1, wherein the distance from the viewpoint position becomes coarser. 4. A creation area for creating a three-dimensional CG map forms a sector from the viewpoint position in a bird's-eye view direction, divides the opening angle θ of the sector into small angles dθ, and calculates elevation data for each dθ and for each unit section dr. reading, 3-dimensional CG map display apparatus according to claim 1, wherein their altitude data characterized by splitting the polygon at the position r _p take maximum or minimum. 5. The method according to claim 1, further comprising storing attribute data of the terrain in association with the elevation data, dividing the terrain information polygon at a position where the attribute data changes, and changing a display mode for each of the divided terrain information polygons. The three-dimensional C according to claim 1
G map display device. 6. A road map data including at least a road represented by a link or a node and used for generating and displaying a moving image of a road when a vehicle is simulated along a route, and for each subdivided area. In the case where the vehicle is simulated along the route and the altitude data defined in the above, based on the altitude data stored in the map memory, a series of 3
Three-dimensional CG map creating means for creating a three-dimensional CG map, and three-dimensional C created by the three-dimensional CG map creating means
A three-dimensional CG map display device having display control means for displaying a G map on a display device. 7. A route calculating means for calculating a shortest route from a current position or a manually set departure point and a manually set destination using a route network database based on nodes or links. 7. The recorded route, wherein the route on which the vehicle simulates is the shortest route calculated by the route calculating means.
3. The three-dimensional CG map display device according to claim 1. 8. An on-vehicle navigation device for detecting a position and a direction of a vehicle and displaying the detected position and orientation together with a road map, wherein at least road map data including a road represented by a link or a node and each subdivided area are defined. A map memory for storing elevation data, and a three-dimensional CG map creating means for creating a three-dimensional CG map that looks at a road map from a viewpoint associated with a traveling vehicle based on the elevation data stored in the map memory; The three-dimensional C created by the three-dimensional CG map creating means
An on-vehicle navigation device comprising: display control means for displaying a G map on a display device. 9. An on-vehicle navigation device for detecting a position and orientation of a vehicle and displaying the detected position and orientation together with a road map, wherein at least road map data including a road represented by a link or a node and each subdivided area are defined. A map memory for storing elevation data, and a three-dimensional CG map creating means for creating a three-dimensional CG map that looks at a road map from a viewpoint associated with a traveling vehicle based on the elevation data stored in the map memory; Using a route network database based on nodes or links, a route calculating means for calculating a shortest route from a current position or a manually set departure point and a manually set destination, In a mode in which the vehicle is simulated for confirmation along the shortest route, a simulation is performed based on the altitude data stored in the map memory. A three-dimensional CG map creating means for creating a series of three-dimensional CG maps looking at a road map from a viewpoint associated with a traveling vehicle; and a three-dimensional C created by the three-dimensional CG map creating means.
An on-vehicle navigation device comprising: display control means for displaying a G map on a display device.