JP2001167288A - 3D map display device - Google Patents

Abstract

(57) [Summary] (With correction) [Problem] In a car navigation device, a large drawing ability is required for drawing a three-dimensional map from a driver's viewpoint. SOLUTION: Whether or not to display the object as an image is determined in advance based on "the height of the object to be displayed" and "distance between the object and the viewpoint position". That is, own vehicle position 2
All the buildings 25 belonging to the inner circle 22 from the inner circle 1 and the inner circle 2
The building 26 belonging to the middle circle 23 and the middle circle 23 sends data to the display device 16 only for buildings of middle class or higher, and the building 27 belonging to the middle circle 23 and outer circle 24 sends data only to buildings of higher floor or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device of a car navigation system for guiding a car, which displays a building using a three-dimensional body.

[0002]

2. Description of the Related Art A conventional car navigation display device displays a current position on an electronically substituted map published in a book or the like, or draws a route to a destination by superimposing the route on the map. , Route guidance. When this map is displayed on the screen, a device is designed such that the traveling direction is set upward, or a two-dimensional map is displayed as a bird's-eye view viewed from an obliquely upper viewpoint.

Further, instead of bird's-eye view display, in order to create an image from the viewpoint of the vehicle, a new navigation system for displaying a building or the like in a three-dimensional manner so as to make the screen and the view seen from the front window of the vehicle as similar as possible. There are car navigation devices that provide images.

[0004]

However, such a 3
When displaying buildings in 3D, if you have to display buildings far away while standing in overlapping buildings like a city, you will need enormous drawing performance . Displaying three-dimensional graphics images requires an average of three times the display capacity of one screen, but drawing a building in the city from the viewpoint of a car requires 20 to 30 times the drawing performance of one screen. It was impossible to display it unless it was a thing.

The present invention solves such a problem, and can display a three-dimensional map while buildings are lined up even with ordinary three-dimensional graphics drawing performance.

[0006]

In order to solve the above-mentioned problems, the present invention displays an object as an image based on "the height of an object to be displayed" and "distance between the object and a viewpoint position". By determining in advance whether or not to do so and controlling the display device, unnecessary drawing can be stopped to perform high-speed drawing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In the following, description will be made assuming a building as an object.

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention. 11 is position, shape, and height data for each building,
It is a map data storage device having data on road positions and shapes. In addition, the building and road data have constant display flag data indicating that they should be always displayed.

Reference numeral 12 denotes position information output means for calculating a viewpoint position for display.
, The current position can be calculated, and the position information can be manually input.

Reference numeral 13 denotes a map data reading device which acquires from the map data storage device 11 data of buildings and roads in a range which can be actually viewed from the viewpoint position obtained from the position information output means 12. For example, a building that is farther than a predetermined distance is out of the readout range because it is virtually invisible.

Reference numeral 14 denotes a distance calculating device for calculating a mutual distance from the position data of the building read by the map data reading device 13 and the position data of the viewpoint from the position information output means 12. For example, the linear distance between the two two-dimensional coordinate values may be calculated and obtained.

Reference numeral 15 denotes whether or not the building is near the viewpoint based on the distance from the distance between the building and the viewpoint calculated by the distance calculation device 14 and the height of the building itself. In order to display all the buildings, the building data is sent to a display device 16 to be described later. On the other hand, in the case of a distant place, it is further determined based on the height that the distant building is not displayed according to the height and the distance from the viewpoint, This is a building selection device for designating only the object to be displayed on the display device 16. Although details will be described later, the height of the building to be displayed can be specified by the distance division from the viewpoint.

A display device 16 displays the building data selected to be displayed by the building selecting device 15.

FIG. 2 is a conceptual diagram for explaining an outline of processing according to an embodiment of the present invention. In FIG. 2, when the own vehicle position to be the viewpoint is 21, an inner circle 22 that displays all buildings if the distance is equal to or less than this distance in accordance with the distance from the own vehicle position 21, and the inner circle 22 that is separated to some extent, If it is far below this distance, it is a middle circle 23 that displays a building above the middle floor, and if it is farther away, it does not display a building, but if it is below this distance and above a middle circle, it is an outer circle 24 that displays only high-rise buildings. A building 25 belongs to the inner circle 22, and the inner circle 22 and the middle circle 2
3, a building 26 belongs between the outer circle 24 and the middle circle 23.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

An embodiment will be described with reference to FIG. 1, FIG. 2, and FIG. When the vehicle is present as shown in FIG. 2, the data of the vehicle position 21 is measured using the position information output means 12 and displayed on the map reading device 13 in order to display the town in a three-dimensional manner. When output as position data (301),
The map reading device 13 reads data of the buildings 25, 26, and 27 from the vehicle position 21 to the outer circle 24 from the map data storage device 11 (302).

The read building data is stored in a distance calculating device 1.
4 based on the position data of the building data,
Then, the distance between the building and the building is calculated (303). If the constant display flag is set, the building is unconditionally selected as a display target (304).

Next, the data on the distance between the building data and the own vehicle position 21 building is sent to the building selecting device 15, and from the height data of the building data and the distance between the own vehicle position 21 building (305),
All the buildings 25 belonging to the inner circle 22 are sent to the display device 16 (308), and the buildings 2 belonging to the inner circle 22 and the middle circle 23 are located.
The data 6 is transmitted to the display device 16 only for buildings of the middle or higher level (306), and the data of the building 27 belonging to the middle circle 23 and the outer circle 24 is transmitted only to the buildings of the higher or higher level (307). The display device 16 performs three-dimensional stereoscopic display of the building from the viewpoint, and can display an image closer to the driver's view of the car.

The processes after 303 in FIG. 3 are controlled so as to be performed for each building.

[0020]

As described above, according to the present invention, a building necessary for navigation is drawn and a neighborhood is drawn by using the height of the building and the distance between the viewpoint and the building to select and draw the building to be displayed. It can be displayed in detail.

In particular, for "a building whose height is remarkably high" which is often used as a mark because it is easy to visually confirm the actual driving of a car, the distance from the viewpoint is considerably large. Can be controlled to be displayed, and a natural and effective display promoted for use in car navigation can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating an embodiment of the present invention.

FIG. 3 is a flowchart illustrating the operation of an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 map data storage device 12 position information output device 13 map data reading device 14 distance calculation device 15 building selection device 16 display device 21 own vehicle position 22 inner circle 23 middle circle 24 outer circle 25, 26, 27 building

Claims (5)

[Claims] 1. A map data storage device that stores map data in which object position data and height data are associated with each other, a position information output device that outputs viewpoint coordinates on the map data, and the position information output device. A map data reading device for extracting map data from the viewpoint coordinates output by the device; a distance calculating device for calculating the distance between the position data of the object obtained from the map data reading device and the viewpoint coordinates; and the height data of the read object. A three-dimensional map display device comprising: an object selection unit that selects an object to be displayed based on the calculated distance; and a display device that displays the selected object. 2. The three-dimensional map display device according to claim 1, wherein said object selecting means divides a distance between the object and the viewpoint into several steps and selects an object according to the step and the distance. 3. The three-dimensional map display device according to claim 1, wherein height data of a map object stored in the map data storage device is stored in advance in several stages. 4. The map object data stored in the map data storage device has a display flag at all times, and when the flag is set, the data is always displayed irrespective of the distance to the viewpoint and the height. 3D map display device. 5. A distance calculating device calculates not only the distance between the viewpoint and the object but also a building vector viewed from the viewpoint. The object selecting device calculates the distance between the object and the viewpoint, the height of the building, the viewpoint vector and the viewpoint building vector. 2. The building to be displayed is selected.
3. The three-dimensional map display device according to claim 1.