JPH0731724B2 - 3D topographic map display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A Field of Industrial Application The present invention relates to a three-dimensional topographic map display device, which corresponds to topographical relief information of topographical pattern information represented on a two-dimensional plane such as a map or aerial photograph. It can be displayed as a three-dimensional topographic map.

B Outline of the Invention The present invention is a three-dimensional topographic map display device capable of displaying a three-dimensional topographic map based on topographic pattern information such as maps and aerial photographs. By mapping the pattern image data,
It is possible to easily create and display a three-dimensional topographic image.

C Conventional Technology When obtaining a three-dimensional topographic map by using a conventional computer graphic box, first a three-dimensional curved surface corresponding to the undulation of the terrain is calculated by the computer, and the three-dimensional curved surface obtained as a result of the calculation is calculated. In order to display a map as a whole on a display device as a three-dimensional image having three-dimensional undulations represented by the contour lines, it is possible to paint different colors as if drawing a map pattern. The method was used.

D. Problem to be Solved by the Invention However, according to this conventional method, there is a disadvantage that a long computing time is required when computing a three-dimensional curved surface that represents undulations of terrain by a computer. In addition, as if drawing a map pattern on a three-dimensional curved surface that represents the ups and downs of the terrain, it is special skill to color the map pattern that gives viewers the impression that they are looking at the terrain itself ( It is very difficult for an operator who does not have such skill to create a three-dimensional topographic map because a so-called painting heart is required.

The present invention has been made in consideration of the above points, and an operator without special skill can easily form a three-dimensional topographic map in a sufficiently short time for practical use. The proposed three-dimensional topographic map display device is intended to be proposed.

E Means for Solving the Problems In order to solve the problems, in the present invention, the topographic pattern image data is obtained on the original surface SOR which is a two-dimensional plane based on the topographic pattern information D _TP , and the topographical relief information is obtained. Based on the D _PH and the viewpoint position information D _POV , the terrain curved surface data SDF representing the undulations of the terrain corresponding to the coordinates on the original surface SOR is obtained, and the terrain pattern image data is converted into an image by the terrain curved surface data SDF. Topographic surface data SDF maps the topographic pattern image data on the topographic curved surface to create a three-dimensional topographic image DIP.

F action Topographic pattern information D The topographic pattern image data represented on the original surface SOR, which is a two-dimensional plane, is created based on _PF , and the topographic relief information is created.
Topographic curved surface data representing the topographical relief is created based on D _PH and viewpoint position information D _POV .

Then, if the topographic pattern image data is mapped onto the topographic curved surface represented by the topographic curved surface data SDF, 2 is displayed on the display image.
In the state where the topographic pattern image data displayed on the original surface SOR which is a three-dimensional plane is pasted on the topographic curved surface represented by the topographic curved surface data, a stereoscopic image similar to that seen from a predetermined viewpoint is displayed on the display device 3. Can be displayed.

Thus, even an operator who does not have a special skill such as painting a terrain pattern on a terrain curved surface can easily create a three-dimensional terrain image.

G Embodiment One embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a three-dimensional topographic map display device as a whole, which is formed on a topographic curved surface creation unit 2 that forms a three-dimensional curved surface that represents the ups and downs of the topography, and on a topographic curved surface created by this topographic curved surface creation unit 2. And a topographical pattern mapping section 4 for mapping the topographical pattern and displaying it on the display device 3.

The topographic pattern mapping unit 4 is a topographic image data memory 11
And a topography pattern signal D _TOM obtained by capturing a map 14 by a television camera 13 and converting the topography pattern data D _TOM in an analog / digital conversion circuit 15. Topographic image data
It is adapted to be stored in the terrain pattern image data memory 11 as D _TP .

Here, the topographic pattern image data D _TP displays contour lines drawn on the map 14, displays rivers, mountains, plains, roads, villages, urban areas, fields, fields, forests, etc. As shown in FIG. 2, the topographic pattern image data, which is composed of the map information in contact with the two-dimensional plane, and thus stored in the topographic pattern image data memory 11, is the original surface SO formed by the two-dimensional plane.
It will be configured by topographic pattern data in which each display element is arranged on R.

In addition to the above configuration, in the case of this embodiment, the topographic pattern mapping section 4 has a topographic pattern database 16 and has the same digital data as the topographic pattern data D _TOM obtained at the output end of the analog / digital conversion circuit 15. Image data consisting of
The D _PIC can be input to the topographic pattern image data memory 11 as the topographic pattern image data D _TP .

The terrain curved surface creation unit 2 is a curved surface creation device having a computer configuration.
Each topographical data D _PLN representing each point on the map is read from the topographical database 22 and the corresponding altitude data D _HIG (Fig. 3) is accessed from the altitude database 23 to construct each map. The altitude data D _HIG corresponding to the position on the xy plane of the display element is read from the altitude database 23 and the position in the z-axis direction is calculated. The result of this calculation is the point of the topographical data D _PLN that represents the position on the xy plane,
It represents a topographic curved surface that is lifted up in the z-axis direction by the amount of altitude data D _HIG representing that altitude.

In this way, the terrain data D _PLN and the altitude data D _HIG are used as the terrain relief information D _PH representing the terrain relief, and the curved surface creation device 2
It is input to 1 and used for the calculation of the topographic curved surface.

The curved surface creation device 21 views the terrain curved surface from the viewpoint position specified by the viewpoint data D _POV input from the viewpoint setting data input means 24 having a joystick configuration, and the same terrain curved surface data SDF (see FIG. 5). ) Is calculated and stored in the topographic curved surface data memory 25.

Here, the viewpoint data D _POV represents the spatial position of the xyz space, and accordingly, when the operator uses the viewpoint setting data input means 24 to change the viewpoint position as necessary, the curved surface creating device 21 Topographical data D _PLN and altitude data D each time
_The terrain curved surface data from a new viewpoint is created based on the _HIG and stored again in the terrain curved surface data memory 25.

The curved surface creation device 21 supplies the terrain curved surface data stored in the terrain curved surface data memory 25 to the image conversion device 12 as image conversion data D _DEF , and displays each of the display elements stored in the terrain pattern replacement image data memory 11 Display position as image conversion data
A conversion operation is performed on the coordinate position on the display screen of the display device 3 designated by D _DEF . Thus, on the display screen of the display device 3, as shown in FIG. 6, a two-dimensional plane map is displayed on the terrain curved surface data SD stored in the terrain curved surface data memory 25.
3D topographic image D created by mapping on the 3D curved surface represented by F
It is designed to get an IP.

Here, as the image conversion device 12, the one disclosed in Japanese Patent Laid-Open No. 58-19975 can be applied, and the topographic pattern image data is mapped on the topographic curved surface by the following procedure.

That is, first, as shown in FIG. 4, the original surface SOR on the xy coordinate where the topographical pattern is represented is divided into minute areas ER having a size as necessary, and one representative point P _R of each divided area ER is divided. , By performing the transformation operation based on the image transformation data D _DEF , the coordinates are transformed on the transformation surface SDF.

Thus, the converted image by the representative point P _R is formed on the deformed curved surface SDF, but the image conversion device 12 continues from the four representative points around the center with each representative point after the conversion as a center.
A parallelogram area of a predetermined size including the center representative point is formed (having a side along the direction connecting representative points adjacent to each other), and the position of each pixel included in this parallelogram area is Obtained by interpolation calculation.

This interpolating operation is performed with the corresponding divided area ER on the original surface SOR,
The position of the pixel in the parallelogram area after conversion is determined on the basis of the positional relationship of each pixel contained therein.

Thus, when the position of each pixel in the parallelogram region on the deformed surface SDF is determined, the image conversion device 12 provides the image information of the corresponding pixel on the original surface SOR to the pixel on the deformed surface SDF. assign. As a result, the topographical pattern drawn on the original surface SOR is image-converted by the image conversion data D _DEF , and the stereoscopic display image pasted on the topographical curved surface (that is, mapped) is displayed on the display device 3. It can be displayed on the display screen.

In the above configuration, the image conversion device 12 outputs the topographic pattern data D _TOM obtained by imaging the topographic pattern on the map 14 with the television camera 13 or outputting the topographic database.
The topographic pattern image data D _TP (FIG. 2) consisting of D _PIC is stored in the topographic pattern image data memory 11 as image data on the xy plane.

In this state, the curved surface creation device 21 has the terrain data D _PLN of the terrain database 22, the altitude data D _HIG of the altitude database 23, and the viewpoint data D _{POV of the} viewpoint setting data input unit 24.
Based on and, the topographic curved surface data SDF (Fig. 5) is formed. This topographic curved surface data SDF is the same image as a stereoscopic image of a three-dimensional curved surface viewed from the viewpoint position is displayed on a two-dimensional plane, and the surface shows unevenness corresponding to the undulations of the terrain. No pattern is attached. Such terrain curved surface data SDF is stored in the terrain curved surface data memory 25, and this is the image conversion data D _DEF.
Supplied to 12.

The image conversion device 12 converts the topographic pattern image data D _EP stored in the topographic pattern image data memory 11 into the original surface SOR (Fig. 4).
The coordinate conversion by the image conversion data D _DEF is executed for each of the above divided areas ER, and as a result, the three-dimensional topographic image DIP (Fig. 6) is created by mapping the topographic pattern image data D _TP on the topographic curved surface data SDF. It will be displayed on the display screen of the display device 3.

With the above configuration, the display device 3 displays the stereoscopic terrain image DI.
When P is displayed, the topographic pattern image data D _TP displayed on the two-dimensional plane is _replaced with the topographic data D _PLN and the altitude data D.
By configuring to map on the terrain curved surface represented by the terrain curved surface data SDF formed by the _HIG and the viewpoint data D _POV , the operator can map on the curved surface representing the undulation of the terrain as in the conventional case. By drawing a pattern, it is possible to easily create a three-dimensional topographic image without the need for a special throwing amount.

Moreover, the operator uses the viewpoint setting data input means 24 to change the viewpoint position to obtain the terrain curved surface data.
By transforming the shape of the terrain curved surface represented by SDF,
It is possible to create a three-dimensional terrain image DIP that is the same as when the terrain is viewed from the specified viewpoint.

The three-dimensional terrain display device 1 having the above-described configuration can be applied to a steering simulation device. In this case, when the viewpoint moves, it is possible to change the range of the topographic pattern data to be read from the topographic pattern image data memory 11, and the range of the topographic data D _PLN and the altitude data D _HIG to be read from the topographic database 22 and the altitude database 23, respectively. Thus, as in the case of moving on the terrain by an airplane, it is possible to obtain a stereoscopic terrain image in which the visual field to be viewed changes according to the movement of the viewpoint.

That is, in the three-dimensional topographic map display device 1 of FIG. 1, the image conversion device 12 causes the image conversion device 12 to obtain a topographic pattern image obtained by taking an aerial photograph with a television camera 13, as shown in FIG. The data D _TP is stored in the topographic pattern image data memory 11. Thus, the image conversion device 12 converts the topographic pattern image data into the image conversion data D from the curved surface creation device 21.
_{If the} image is converted by the _DEF and displayed on the display device 3, the aerial photograph 31 is mapped on the topographic curved surface data SDF (Fig. 5) on the display screen of the display device 3 to form a three-dimensional terrain. An image DIP (Fig. 8) is obtained.

The three-dimensional topographic image DIP of FIG. 8 has a three-dimensional topographic map as seen from a viewpoint in the upper front position over a predetermined area of the aerial photograph 31. In this state, the viewpoint is left as indicated by an arrow 32. If you move backwards, the area of the aerial image 31 that you see from a new perspective should move to the left rear.

From this point of view, the curved surface creation device 21 _moves the range of the topographic data D _PLN read from the topographic database 22 and the range of the altitude data D _HIG to be read from the altitude database 23 to the left rear as shown by the broken line in FIG. After the movement, the topographic data D _PLN and the altitude data D _HIG are read. At this time, since it is not necessary to store the data of the right front portion that becomes invisible due to the movement of the viewpoint in the topographic curved surface data memory 25, the data that needs to be newly stored in the memory area that is no longer needed. By storing it, the terrain data D _PLN accompanying the movement of the viewpoint can be stored without increasing the capacity of the terrain curved surface data memory 25.
And altitude data D _HIG can be replaced.

Image conversion data that changes as the viewpoint moves
When D _DEF is supplied from the curved surface creation device 21 to the image conversion device 12, the image conversion device 12 causes the topographic pattern image data memory 11 or the topographic pattern image data D to be read as shown in FIG.
Move _TP to the left rear area in the same manner as in FIG.

By doing so, it is possible to display a stereoscopic terrain image on the display screen of the display device 3 as if the operator were boarding an aircraft and looking at the lower right terrain.
Therefore, it is possible to realize a suitable three-dimensional topographic map display device by applying it to a steering simulation device.

H Effect of the Invention As described above, according to the present invention, even an operator having no special skill can easily obtain a three-dimensional terrain image DIP that appears to have the same undulations as the terrain. It is possible to obtain a stereoscopic topographic map display device that can be created.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a three-dimensional topographic map display device according to the present invention, and FIG. 2 is a schematic diagram showing topographic pattern image data D _TP supplied to the image conversion device 12 of FIG. Figure 3 shows the terrain database 22 and altitude database 23 in Figure 1.
4 is a schematic diagram showing the topographical relief data D _PH stored in FIG. 4, FIG. 4 is a schematic diagram showing an original surface SOR created by the image conversion device 12, and FIG. 5 is a curved surface creation device 21 of FIG. FIG. 6 is a schematic diagram showing the created terrain curved surface data SDF, FIG. 6 is a schematic diagram showing a stereoscopic terrain image DIP displayed on the display device 3, and FIG. 7 is an aviation used in another embodiment of the present invention. FIG. 8 is a schematic diagram showing topographic image data based on a photograph, FIG. 8 is a schematic diagram showing a three-dimensional topographic image DIP obtained by converting the aerial photograph of FIG.
FIG. 10 and FIG. 10 are schematic diagrams showing changes in data when the viewpoint moves in FIG. 1 ... 3D topographic map display device, 2 ... Topographic curved surface creation unit, 3
...... Display device, 4 …… Topographic pattern mapping section, 11 …… Topographic image data memory, 12 …… Image conversion device, 13 ……
Television camera, 14 …… Map, 21 …… Curved surface creation device, 22 …… Terrain database, 23 …… Altitude database, 24 …… Viewpoint setting data input means, 25 …… Terrain surface data memory.

Claims (1)

[Claims] 1. A topographic pattern image data generating means for capturing a map and generating topographic pattern image data showing a topographic pattern on a two-dimensional plane, and the topographic pattern image data generated by the topographic pattern image data generating means. And a second storage means for storing altitude data indicating the height at each point of the topographical pattern, an input means for inputting viewpoint position data indicating the position of the viewpoint, and the altitude Topographic curved surface data generating means for generating topographic curved surface data indicating the undulations of the terrain with respect to the coordinates on the two-dimensional plane based on the data and the viewpoint position data, and the topographic curved surface data output from the topographic curved surface data generating means. And the topographic pattern image data read from the first storage means, and the topographic pattern image data is indicated by the topographic curved surface data. A three-dimensional terrain map, comprising: mapping means for creating data showing a three-dimensional terrain image by mapping on a curved surface to be displayed; and display means for displaying the three-dimensional terrain image created by the mapping means. Display device.