JPH11232484A - Method for generating three-dimensional city data, its device and measuring instrument for surveying three-dimensional city data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring the heights of buildings being suitable to construct a three-dimensional city database and also to provide the modeling method of the buildings. SOLUTION: The data generating method is provided with surveying steps for collecting data including height information of the buildings at every block (S2 and S3), modelling steps for executing the stereoscopic modelling of the buildings, based on the collected data (S1, S4 and S5) and an integrated step for incorporating data generated by the modelling steps so as to generate the three-dimensional city database (S6). A less handling time is required in measurement at every block than that at every building. Modelling is discriminated in accordance with the important degrees of the buildings so that a data amount can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for generating three-dimensional city data for digitizing and storing three-dimensional city information, a system therefor, and a modeling method therefor.
Also, the present invention relates to an apparatus for applying three-dimensional city data.

[0002]

2. Description of the Related Art In recent years, with the spread of car navigation systems and the like, the demand for electronic maps replacing conventional maps has been increasing. A conventional electronic map of this type is a two-dimensional map that displays a state in which roads and buildings are viewed from above, similarly to a conventional road map. However, with the advance of image processing technology, demand for a three-dimensional city database in which three-dimensional information in the height direction is added to a conventional map has been increased. If a three-dimensional city database is used, a real city screen can be provided from various viewpoints. For example, you can freely move around the city by operating a computer, and understand an unknown city before going to the site.

[0003] In constructing a three-dimensional city database, the first problem is how to actually construct a three-dimensional city database.
Either collecting data on the dimensions, especially the height of the building, or how to model the building. As a conventional method for creating three-dimensional city data, for example, Japanese Patent Laid-Open No. 4-293
No. 078, "How to create 3D data for map model"
Discloses a method for creating a smooth three-dimensional terrain model by calculating height data based on point sequence data for mesh points on a two-dimensional plane having a smaller pitch than contour line point sequence data. I have.

[0004]

However, although the contours of the terrain are displayed on the conventional map, the height of the building is not described at all. When trying to construct a three-dimensional city database of an actual city, collection of data in the height direction of the building and modeling of the building are very large problems, and have hindered the realization of the three-dimensional city database.

[0005] Nikkei Computer Graphics 199
In the April 2007 issue, an article was published titled "How to explore the potential of three-dimensional city maps and how to break the huge development cost barrier." In this article: "Although there is software that displays mountain areas in three dimensions based on elevation data, there is only very coarse accuracy. Map data of urban areas is still in the process of finding, but the expectations of developers and users are high." However, "If you use it in real work, you will need to model a wider area and the cost will be enormous. In addition, it will be a great deal of labor and money to update the city that changes every day. There is. ""Most Japanese cities are densely populated with small buildings, which will require man-made tactical surveying." Therefore, it is stated that there is a modeling method using a helicopter or a satellite photograph.

[0006] In the August 1997 issue of the magazine,
The article is published under the title of "3D City" Philadelphia 2000 Project "". While referring to the potential of 3D cities, this article states that "the most fundamental challenge is how to gather all the information needed for modeling." Point out.

[0007] As can be seen from the above-mentioned documents, while recognizing the usefulness of the three-dimensional city database, it suffers from the barriers of how to model for realizing it and the cost of collecting information for that purpose, and has found a solution. Did not.

The present invention has been made to solve such a problem, and provides a method of measuring the height of a building and a method of modeling a building suitable for constructing a three-dimensional city database.

[0009]

A three-dimensional city data generating method according to the present invention includes a surveying step of collecting data including height information of a building in a city, and a three-dimensional building data of the building based on the collected data. A modeling step for performing detailed modeling, and an integration step for generating a three-dimensional city database by incorporating data generated by the modeling step.

[0010] In the three-dimensional city data generation method according to the present invention, the surveying step includes a height discriminating step of measuring a distance and an angle in order to calculate a height of the building; Performing a photographing step.

In the method for generating three-dimensional city data according to the present invention, the surveying step is performed on a block including a plurality of buildings, and the survey of each building is performed on a corner building from the direction of the corner, and the building is checked. Investigate the characteristic part. This makes it possible to obtain data necessary for practical use, and to perform a more efficient survey than when investigating individual buildings.

In the three-dimensional city data generation method according to the present invention, the surveying step is performed on a block including a plurality of buildings, and the survey of each building is performed only at a corner of the block. This allows for a more efficient investigation.

[0013] In the three-dimensional city data generation method according to the present invention, in the surveying step, the building is photographed using a digital camera, and the height of the building is determined based on pixel data of the photographed image. . Since the height measurement of the building can be performed together with the photographing, an efficient survey can be performed.

[0014] In the three-dimensional city data generating method according to the present invention, the modeling step distinguishes modeling according to the importance of the building. The building can be divided into models suitable for importance, and the building can be represented by a data amount according to the role that the building plays in the three-dimensional city database. Therefore, modeling can be performed while suppressing an increase in the amount of data.

[0015] In the three-dimensional city data generation method according to the present invention, the A-ranking, which is important for improving the accuracy and realization of the three-dimensional city database, is required to be accurately reproduced in the database. Building and
B-ranked buildings that are relatively important to enhance the accuracy and realism of the three-dimensional city database and need to be reproduced somewhat accurately in the database, and buildings that are less important than A-ranked and B-ranked buildings And the shape of the site other than the building. When targeting real cities, such a ranking allows for optimal modeling.

In the method for generating three-dimensional city data according to the present invention, the model of the A-ranked building is constituted by a plurality of polygons in a virtual space, and the plurality of polygons is a polygon of a signboard on a roof and a rooftop. , A window polygon, an outer wall polygon, a sloped roof polygon, and an entrance / exit polygon.

In the three-dimensional city data generating method according to the present invention, the model of the B-ranked building is composed of a plurality of polygons in a virtual space, and the plurality of polygons are a rooftop polygon and a window polygon. , Exterior wall polygons, sloped roof polygons, and entrance / exit polygons.

In the method for generating three-dimensional city data according to the present invention, the model of the C-rank building may include a rooftop polygon, a window polygon, a box-shaped outer wall polygon, a sloped roof polygon, and an entrance / exit. Including polygons.

In the three-dimensional city data generating method according to the present invention, the rooftop polygons are arranged outside the polygons of the outer wall at predetermined intervals. This prevents malfunctions in the computer, such as when polygons are placed at the same position, confusion about which polygon should be processed by the computer, and the inability to perform rendering or other processing correctly. it can.

In the three-dimensional city data generating method according to the present invention, the window polygons are arranged outside the polygons of the outer wall at predetermined intervals.

In the three-dimensional city data generating method according to the present invention, image data of a wall surface of a building photographed in the surveying step is pasted as a texture on the polygon of the outer wall. This makes it possible to easily express a realistic feeling about the wall surface. In addition, photograph the entire wall of the building,
Expressing windows and doorways on the wall by pasting this as a texture on the polygon is not practical because it is difficult to photograph the entire wall. On the other hand, pasting the image data of the wall surface of the building as a texture is equivalent to the image data of the wall surface (for example, a brick expression,
(Tile expression, concrete expression, etc.) is used as a part, so photographing itself is relatively easy.

In the three-dimensional city data generating method according to the present invention, the modeling step provides a height difference to a polygon on a site other than the building. As a result, the three-dimensional city data can be configured more intuitively. This is effective, for example, when the viewpoint moves along the ground surface as in a car navigation system.

In the three-dimensional city data generating method according to the present invention, in the modeling step, the actual inclination is approximately 1: 1.
When it is 00, no height difference is provided, and when the actual inclination is approximately 1:20, a height difference is provided. Based on the experimental results, by providing a height difference within the required range,
It is possible to save time and effort for generating two-dimensional city data and suppress an increase in the data amount.

In the three-dimensional city data generation method according to the present invention, when the modeling step includes at least a road polygon, a building site polygon, and an intersection polygon as the types of the site, the polygon at the intersection is converted to the polygon at the intersection. The difference in height is expressed by performing a triangulation on the portion to be excluded. The reason why the intersection is included is as follows. (1) In many cases, since the height reference is concentrated on the intersection, it is easy to input the height described on the map. (2) Because the width direction of the road near the intersection is always horizontal by using the intersection as a reference, it is easy to use as three-dimensional city data of the city. (3) The position of the road is very high in this city data.
Also, the intersection is excluded from the triangulation because, in many cases, the intersection is considered to be a plane. Therefore, intersections of complex shapes that cannot be considered planes
It is not included in the intersection mentioned here.

A three-dimensional city data generating apparatus according to the present invention includes an input unit for receiving data including height information of a city building, and a modeling processing unit for performing three-dimensional modeling of the building based on the input data. And a storage unit for storing data generated by the modeling processing unit. The modeling processing unit is important for improving the accuracy and realization of the modeling of the building in a predetermined three-dimensional city database. A-ranked buildings that need to be accurately reproduced in the database, and are relatively important to enhance the accuracy and realism of the three-dimensional city database, and need to be reproduced somewhat accurately in the database It is divided into a building of B rank, a building of lower importance than the buildings of A rank and B rank, and the shape of the site other than the building.

In the three-dimensional city data generating apparatus according to the present invention, the model of the A-ranked building is composed of a plurality of polygons in a virtual space, and the plurality of polygons is a polygon of a signboard on a roof and a rooftop. , A window polygon, an outer wall polygon, a sloped roof polygon, and an entrance / exit polygon.

In the three-dimensional city data generating apparatus according to the present invention, the model of the B-rank building is composed of a plurality of polygons in a virtual space, and the plurality of polygons are a rooftop polygon and a window polygon. , Exterior wall polygons, sloped roof polygons, and entrance / exit polygons.

In the three-dimensional city data generating apparatus according to the present invention, the model of the C-ranked building is a rooftop polygon, a window polygon, a box-shaped outer wall polygon, a sloped roof polygon, and an entrance / exit. Including polygons.

[0029] In the three-dimensional city data generating apparatus according to the present invention, the modeling processing section may convert the rooftop polygon into
It is arranged outside the polygon of the outer wall at a predetermined interval.

[0030] In the three-dimensional city data generating device according to the present invention, the modeling processing unit arranges the polygons of the window at predetermined intervals outside the polygons of the outer wall.

[0031] In the three-dimensional city data generating apparatus according to the present invention, the modeling processing unit may include:
The image data of the wall surface of the building taken in advance is pasted as a texture.

[0032] In the three-dimensional city data generating apparatus according to the present invention, the modeling processing section provides a height difference to a polygon on a site other than the building.

[0033] In the three-dimensional city data generating apparatus according to the present invention, the modeling processing section may be configured such that the actual inclination is approximately 1:
When it is 100, no height difference is provided, and when the actual inclination is approximately 1:20, a height difference is provided.

[0034] In the three-dimensional city data generating apparatus according to the present invention, when the modeling processing unit includes at least a road polygon, a building site polygon, and an intersection polygon as the site types, the intersection polygon is used. The height difference is expressed by performing triangulation on the portion excluding.

A recording medium according to the present invention stores a program for causing a computer to function as the modeling processing section.

The medium includes, for example, a floppy disk,
Hard disk, magnetic tape, magneto-optical disk, CD-
Includes ROM, DVD, ROM cartridge, RAM memory cartridge with battery backup, flash memory cartridge, nonvolatile RAM cartridge, and the like.

The communication medium also includes a communication medium such as a wired communication medium such as a telephone line and a wireless communication medium such as a microwave line. The Internet is also included in the communication medium mentioned here.

A medium is a medium on which information (mainly digital data and programs) is recorded by some physical means, and which allows a processing device such as a computer or a dedicated processor to perform a predetermined function. You can do it.
In short, any method may be used as long as the program is downloaded to the computer by some means and a predetermined function is executed.

The three-dimensional city data surveying measuring device according to the present invention is used for collecting data of city buildings in a surveying step of the three-dimensional city data generating method.
The digital camera includes a hand level for measuring an angle, a ranging for measuring a distance, and a digital camera for photographing a building, wherein the hand level, the ranging, and the digital camera are integrally configured.

A measuring device for three-dimensional city data survey according to the present invention is a digital camera used for collecting data of a city building in a surveying step of a three-dimensional city data generation method, comprising: an electric level; Display means for displaying a horizontal line in the viewfinder screen based on the output of the electric level for adjusting the orientation of the digital camera, pointing means for designating a measurement point of the building, and Output means for outputting image data and pixel information of the measurement point.

In the measuring device for three-dimensional city data survey according to the present invention, the digital camera further includes a ranging for measuring a distance, receives the image data, the pixel information of the measuring point, and the distance information, A portable information terminal that calculates the angle of the measurement point from the pixel information of the measurement point and calculates the height of the measurement point from the distance information and the angle;

A three-dimensional car navigation system according to the present invention includes a three-dimensional city database, a position sensor for obtaining position information, a direction sensor for obtaining a traveling direction, a display unit for displaying a navigation screen, the position sensor and the position sensor. A processing unit that determines a viewpoint and a line of sight based on an output of the direction sensor, and generates a display image from data of the three-dimensional city database based on the viewpoint and the line of sight.

Preferably, the current address, the situation in the direction of travel (whether traffic is congested or vacant, etc.), the situation on the left and right (whether the left and right roads can be used as a detour, the time required when detouring, the detour May be provided together with additional information such as interests and losses due to the additional information. Also,
A display selection unit that switches between three-dimensional display and normal planar display manually by a user's operation or automatically according to the display content of the map may be provided. As a specific example of the automatic selection method, a three-dimensional display is used during driving, and a planar display is used to check the status of surrounding buildings (for example, for indicating the location of a public facility, a specific company, a restaurant, etc.). It is possible.

The shadow simulation system according to the present invention is based on a three-dimensional city database, information on the position, height and shape of a predetermined building obtained from the three-dimensional city database, and a given sun position. And a processing unit for determining the shaded area by finding the line of

The position of the sun may be moved to obtain a shaded area at a predetermined time. For example, it is possible to obtain an area that is shaded all day during the winter solstice, an area that is temporarily shaded, and an area that is not shaded at all.

The radio interference simulation system according to the present invention provides a radio wave based on a three-dimensional city database, information on a predetermined building position, height and shape obtained from the three-dimensional city database, and a given radio source position. A processing unit that obtains a failure situation.

The processing unit includes a first processing unit for obtaining a radio wave interference state with respect to a radio wave having a strong linearity such as a microwave, and a second processing unit for obtaining a radio wave interference state with respect to a relatively long wavelength radio wave.
And a processing unit. Further, a third processing unit for obtaining a radio interference situation in consideration of diffraction of radio waves in the height direction of the building and a fourth processing unit for obtaining a radio interference situation in consideration of radio wave interference over the entire side surface of the building are provided. May be.

A three-dimensional city information display system according to the present invention displays a three-dimensional city database, an attribute information database for storing attribute information of buildings in the three-dimensional city database, and a display screen based on the three-dimensional city database. A processing unit for generating and adding attribute information to the display screen based on the attribute information database; and a display unit for displaying city information and attribute information based on an output of the processing unit.

The attribute information is displayed in a comment box or on the surface of a building (graphically, instead of texture).

The attribute information database includes general attribute information and detailed attribute information, and the processing unit displays a first processing unit for displaying the general attribute information and the detailed attribute information. And a second processing unit. For example, when a building is enlarged and displayed, detailed attribute information is displayed.

Further, the processing unit changes the viewpoint moving means for moving the viewpoint in the three-dimensional city database in accordance with a predetermined operation, changes the display screen with the movement of the viewpoint, and changes the display of the attribute information. A third processing unit may be provided. When the viewpoint is moved from one viewpoint to another, the content of the displayed attribute information changes accordingly.

Further, the processing unit may include a fourth processing unit for automatically or transparently expressing the surface of the building in response to a predetermined operation or a situation. Be able to see through the interior of the building.

[0053]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention A method for generating three-dimensional city data according to Embodiment 1 of the present invention will be described with reference to the drawings.

The method according to the first embodiment of the present invention is roughly divided into a surveying step of collecting data of actual city buildings, and a step of modeling a city building based on the collected data. Integrating the data generated by modeling into a built-in three-dimensional city database.

This is described in the flow chart of FIG. According to FIG. 1, a two-dimensional input for creating a survey map is performed in advance (S1). Then, go out for a survey and determine the height to calculate the height of the building (S
2) Take a reference photo of the target building (S
3). Bringing back these survey results, create a general-purpose database that adds the height of the building to the two-dimensional map data (S4), and add an option to reduce the amount of data and make the representation of the building more realistic. (S
5). Then, a built-in process for integrating the created building data is performed (S6), and a three-dimensional city database is generated.

Steps S2 and S3 in FIG. 1 correspond to an investigation step, steps S1, S4 and S5 correspond to a modeling step, and step S6 corresponds to an integration step.

Hereinafter, each processing will be described in detail in the order of the investigation step, the modeling step, and the integration step.

1.1 Investigation Step Prior to the investigation, preparations are made. The details will be described later, but the outline is as follows. First, the cities to be created are divided into areas, taking into account the ease of research and modeling work. Next, the current state map (planar map) is scanned, and two-dimensional line segment data is input using the scanned image as a sketch. 2
The three-dimensional line segment data is printed out by three copies, and a survey file is created for each area. These are the entry form for height discrimination, the record for reference photo shooting,
Reserved. Create a browsing table using a copy of the 1/5000 status chart. This is used to record the progress of the survey and modeling. At the same time, the buildings corresponding to ranks A and B are checked in advance with reference to the house map. Building ranking is very important for generating a highly accurate three-dimensional city database while suppressing an increase in the amount of data. The details of the rank of this building will be described later.

The height determination is carried out by using the ordinary principle of triangulation as shown in FIG. For this purpose, researchers use a ranging device that measures distance using lasers or ultrasonic waves (ranging).
101, a digital camera 102 for specifying measurement points, a tripod 103 with a level / protractor, a file for investigation, and the like.

At the site, the investigator said that ranging 10
1 and a tripod 10 to which a digital camera 102 is attached
Set 3 horizontally. The state at this time is shown in FIG. The ranging 101 and the digital camera 102 are fixed to a base of a tripod 103 that rotates about a vertical axis. At this time, the height of the ranging 101 and the digital camera 102 is
H1. Next, the horizontal distance L from the measurement point to the building is measured by ranging. Next, the digital camera 10
The protractor of the tripod 103 is adjusted so that the center (or a predetermined position) of the finder 2 is aligned with the top of the building to be investigated, and the angle θ is read. Here digital camera 102
The use of is intended to facilitate the photographing, which is the next task, and to transmit survey data online by connecting via a communication line. Perform the above operations for all buildings. However, tripod 103
It is desirable to fix work in one place as much as possible and measure the height of as many buildings as possible to reduce the work time.

The height H of the building is given by the following equation.

H = h1 + Ltan θ If the measurement accuracy does not matter much, a hand-held measuring instrument can be used without using a tripod. In this case, the work efficiency is improved by the necessity of the tripod fixing work.

The photographing of the building is performed as follows. The building to be surveyed is photographed in order for each block of the area division prepared in advance. Here, a block is a minimum unit for creating data, and is a unit surrounded by a road or a river. Basically, one block depends on one address, but in some cases, one address may extend over a plurality of blocks, or one block may extend over a plurality of addresses. In this case, the final data depends on the address and the latter depends on the block.

The photographing of the building is basically based on the photographing of four sides of the building. However, in the buildings other than the ranks A and B, only the road side is photographed. Basically, it is taken from the eye level. In addition,
If there is something difficult to shoot from the ground, such as a tower, model separately with reference to aerial photographs.

FIG. 4 is a diagram for explaining a method of photographing a building. This figure is a plan view of one block 110, which has a total of ten buildings separated by relatively wide roads. In the figure, the arrow indicates the shooting direction, and the number at the tip of the arrow indicates the serial number of the shooting. FIG.
As can be understood from FIG. 7, the object and the direction to be photographed are not always constant. These are selected from the following viewpoints.

For buildings other than A and B ranks, the road side is photographed from the front. This is because buildings other than A and B ranks are not so important, and high-precision modeling is not required.

The corner building is photographed not from the front but from the direction of the corner. This is because, by photographing from this direction, the characteristics of the building can be understood well, and information about two surfaces can be obtained from one photograph, so that the number of times of photographing can be reduced.

When a characteristic shape of a building, for example, a corner is not a simple right angle but a complicated shape, or there is a characteristic at a boundary with an adjacent building, the portion is photographed. Such features are important for improving the accuracy of a three-dimensional city.

When the photographing object and the direction are selected from the above viewpoints, the number of times of photographing is obtained by adding the number of the characteristic shape portions to the number of buildings. In the survey data obtained as described above, the position, direction, and number of images taken are entered in a survey file and arranged so that a photograph required for modeling can be immediately searched. If the local situation has changed due to new construction or demolition, write the details in the survey file,
For a new building, write down its plan shape and position. After the survey data is converted into height data, it is stored together with the image data of the digital camera.

1.2 Modeling Step Modeling refers to creation of shape data actually represented on a computer or the work itself. The modeling is performed, for example, on a computer (a personal computer, a workstation, or the like) having a configuration as shown in FIG. A CPU (processor) 10 includes a CRT 11, a keyboard 12, and a mouse 1 as input / output devices.
3. RAM 14, ROM 15, hard disk 16 as storage means, FLD drive 17, as external storage means,
A CD drive 18, an MO drive 19, and a modem 20 as communication means are provided.

The main work steps for creating a three-dimensional city database of a city are as follows.

(1) Two-dimensional data input: Two-dimensional data composed of planes is created.

(2) Input of three-dimensional data: three-dimensional data composed of three-dimensional data is created.

(3) Special terrain input: Three-dimensional terrain, such as mountains and rivers, different from cities is created.

(4) Option input: The basic shape database is edited.

Before proceeding with a description of the processing contents of the above steps, the features of modeling in a three-dimensional city database of cities will be described. The model of the three-dimensional city database according to Embodiment 1 of the present invention is classified into site shape data, A-ranked buildings, B-ranked buildings, and C-ranked buildings.

The site shape data is the shape data of the ground surface other than buildings such as roads and sites, and specifically, there is the one shown in FIG. These are essential for improving the accuracy of the three-dimensional city database and making it more realistic, but there is not much need to collect data during field surveys. Therefore, the classification is performed based on the existing map data, and the expression level as shown in FIG. 6 is selected based on the classification result. Specifically, this is performed as follows. 1/25
Using two-dimensional data obtained by digitizing the current status map of 00,
Create roads, sites, etc. For example, the tree is the present situation 1/2
Only those listed in 500 are subject to modeling,
Moreover, only the coordinates are input without creating the shape. White lines on the road are created by using the aerial photograph and confirming the number of lanes and the display on the road. Elevators, bridges, pedestrian bridges, etc. are created by confirming their shapes with photographs.

In FIG. 6, the meaning that the heights of the site, the road, the road white line, and the like are 0, -0.2, and -0.15 (for example, the unit is "m") will be described. Generally, the road is lower than the site for better drainage, so the site can be given a slightly higher position than the road when modeling. On the other hand, the road and the road white line are usually at the same height, but are set so that the road white line is slightly higher during modeling. This is due to a requirement in computer graphic processing. That is, in a three-dimensional computer graphic, a solid is represented by using a plurality of polygons (polygons), and a color and a pattern are represented by attaching a texture to the polygon. As a method of expressing a road and a road white line, a method of expressing a road with a polygon and expressing the road white line with a texture attached to the polygon is considered. However, in the three-dimensional city database according to the first embodiment of the present invention, it is more sensible to represent the two in a distinctive manner. Therefore, this method is not adopted, and both the road and the road white line are represented by polygons. doing. In this case, if the road and the road white line are at the same height, it may be confused and confused as to which material (texture) should be represented by computer processing. Therefore, the road white line is set higher to the extent that there is no practical problem (if it is set lower, the road white line is buried and cannot be expressed). An A-ranked building is a building that is important for improving the accuracy and realism of a three-dimensional city database and that needs to be accurately reproduced in the database. A-ranked buildings with a height of 8 floors or more, large buildings occupying 1/4 of a block, or public facilities, schools,
Buildings with high profile, such as hospitals, city hotels, historic buildings, and landmark buildings, are selected. FIG. 7 shows an example of an expression criterion for a building of rank A. FIG. 10 shows an example of the expression. Modeling of a building of rank A is performed, for example, in the following procedure. The location of the building is
2500) is determined using the digitized two-dimensional data. It is created using the photographs taken in the above-mentioned investigation step and the height data of the building. The shapes of buildings, low rises, towers, barcos, stairs, rising of parapets, windows, rooftops, and irregularities on the walls that can be judged from photographs are represented by polygons. As can be seen from FIG. 7, the buildings of rank A are signboards,
It is divided into six categories: rooftops, windows and glassy doorways, outer walls, pitched roofs, and non-glass doorways. By expressing buildings by polygons of a plurality of categories in this manner, a precise three-dimensional city database can be constructed.

In FIG. 7, a description will be given of the meaning that the roof, the window, and the glass entrance are all floated by 0.05. This is due to a requirement in computer graphic processing. The roof, windows, and glass-like doorway are all represented using polygons (polygons) in order to enhance accuracy and realism. In this case, if they are at the same height, it may be confused and confused as to which material (texture) should be represented by computer processing. Therefore, the roof, the window, and the glass are slightly lifted from the polygons constituting the wall surfaces.

The B-rank building is a building that is relatively important for improving the accuracy and realism of the three-dimensional city database, and that needs to be reproduced in the database with some precision. As the B-rank building, a relatively large building having a height of 4 floors or more, occupying 1/9 of one block, or a general office building not included in the A-rank building is selected. FIG. 8 shows an example of an expression standard for a B-rank building. FIG. 11 shows an example of the expression. Modeling of a B-rank building is performed, for example, in the following procedure. The position of the building is determined using two-dimensional data obtained by digitizing the current state map (1/2500). It is created using the photographs taken during the survey (four buildings) and the height. The shape of the building that can be judged from the photo, Barco 21, windows,
Express the rooftop. As can be seen from FIG. 8, buildings of rank B are divided into five categories: rooftops, windows and glassy entrances, exterior walls, sloping roofs, and entrances other than glass. In FIG. 8, the reason why the roof, the window, and the glass-like doorway are all floated by 0.05 is as described above.

The C rank building is a building having a lower importance than the A rank and B rank buildings. C-tank buildings include low-rise houses other than A and B ranks, covered bicycle parking lots, etc. (excluding temporary houses).
FIG. 9 shows an example of an expression standard for a C-rank building. Modeling of a C-rank building is performed, for example, in the following procedure. The position of the building is determined using two-dimensional data obtained by digitizing the current state map (1/2500). Basically, the shape is generated by selecting an appropriate model using a database (library) generated in advance, and correcting the shape and height of the selected model according to the survey result. I do. Basically, a box-shaped model is selected, and the roof, rooftop, entrance facing the road, and windows are individually modified and represented. As a model of the C-rank building, for example, a simplified model as shown in FIG. 12 is used. In FIG. 12, reference numeral 120 denotes a two-story reinforced house model,
Reference numeral 121 denotes a one-story wooden house model. Symbol 120
Reference numerals a, 120b, 120c, 120d, and 120e denote an outer wall, a rooftop, a doorway other than glass, a window, and a sloped roof, respectively. In addition, a model of a three-story reinforced house and a two-story wooden house can be considered. As described above, it is not necessary to create a shape from the beginning for modeling a C-rank building, and efficient work can be performed.

The number of polygons required to represent a building of each rank A, B, C is approximately 1: 0.5: 0.2
It becomes 5. Therefore, by appropriately ranking as described above, the data amount can be reduced without lowering the accuracy of the three-dimensional city database. The shape data thus created is stored and managed for each address.

Next, (1) two-dimensional data input, (2) 3
The processing contents of each step of dimensional data input, (3) special terrain input, and (4) option input will be sequentially described.

(1) Modeling of two-dimensional data Two-dimensional data is created before the investigation. The reason is that the output of the two-dimensional data becomes the survey map. The creation procedure is as shown in FIG.

Scanning the current state chart of 1/2500,
Image data to be a sketch is created (S10).

The coordinate axes and scale of the sketch are adjusted using modeling software (S11).

[0101] Two-dimensional data is created (S12). That is, the outline of the road, the site, the building, the overpass, the bridge and the like and the positional relationship are traced in the sketch. However, as for the tree, only the coordinates described in the 1/2500 status chart are input as linear data. For the white line, use the aerial photograph to check the number of lanes and display on the road before entering.

The completed two-dimensional data is stored for each area (S13).

The two-dimensional data completed in this way is, for example, as shown in FIG. 4 and serves as a base for the final three-dimensional shape data, and is adjusted and output so that there is no defect. The result is a survey map.

(2) Modeling of three-dimensional data Shape data is created based on digitized two-dimensional data, a result of height discrimination, and a reference photograph. The shape data is divided on a layer basis, and is created according to the procedure shown in FIG.

The two-dimensional data of the area to be created is called, and further, the address is divided into units. However, at this time, the road is stored as it is in the unit of work (S20).

[0092] Three-dimensional data is input for each address. Details are as shown in FIGS. 7 to 9 (S21).

It is checked whether there is a layer division, a duplication of shapes, and a front / back of each component, and saves them (S22).

The modeling data is converted to DXF (Drawing Excha).
nge Format) format (S23). Shape data for final operation is obtained by performing DXF conversion. Others are data for creation record and update.

(3) Modeling of special terrain Special terrain refers to terrain that requires an unusual creation method, such as a mountain, river, or park having a large area. A representative example of this and a method for creating the same will be described below.

The mountain and its associated buildings and roads are shown in FIG.
5 is generated in accordance with the procedure of FIG.

Assuming that the last contour line (the contour of the mountain) is the same as the boundary of the city in contact with the mountain, the contour lines described on the map are digitized with linear data (S3).
0).

The buildings and roads attached to the mountain are digitized from the sketch (S31). 2 by steps S30 and S31
Dimensional information is generated.

The last line of the contour line is adjusted to the highest position of the intersection at the boundary of the city, and the height is input (S3).
2). As a result, the height of the last contour line is 3
The data of the mountains (special terrain) and the data of the city are integrated with the one-dimensional city data.

A mountain is created from the contour lines (S33). That is, the elevation of the contour line is sequentially set based on the elevation of the last line of the contour line, and the height is given to the contour line based on the set elevation, thereby expressing the mountain three-dimensionally. Note that this processing can be automatically performed as long as the altitude of the last contour line is given.

A digitized building and a road are created and arranged according to the height of the mountain (S34). Since the mountain was three-dimensionally represented in the previous step, the building is three-dimensionally represented in accordance with the three-dimensional representation, and is arranged according to the altitude.
By this processing, the three-dimensionally represented buildings and mountains and the roads are combined in a space with a correct positional relationship.

The storage size is divided (S3
5). When the data amount becomes large, the three-dimensional city data is divided into units convenient for handling. In the case of saving, it is desirable not to divide as much as possible. However, if it is absolutely necessary, division that is easy to manage, such as dividing by address or by layer, is performed.

The storage is performed (S36). When division is performed, it is convenient to describe a name that clearly indicates the division.

The same processing as in the case of a mountain is performed for a river and its accompanying ones.

For a large park, terrain such as turf, soil, river, sidewalk, etc. is input within a range that can be seen in the sketch. The building on the premises is the same as the normal creation method.

For other special terrain, for example, a terrain with a remarkable height difference mainly found in natural objects, etc., the same creation as a mountain or river is performed. In addition, the topography with little difference in elevation, such as a port and a landfill, is the same as a park.

(4) Option When operating three-dimensional city data, processing for editing the basic shape data in some form may be required. This process is called an option. Options are broadly classified into five types. The first is L
OD (Level Of Detail). This is a process of adjusting the degree of detail of the expression of the building by adding or deleting shape data, and constructing three-dimensional city data with optimal accuracy in view of the data amount. The second is a process of adding a street furniture object such as a street lamp, a signal, or a sign that constitutes a city. Third, the texture of the building,
For example, it is a process for expressing a difference in material such as a metal and a concrete.

The fourth is a process for performing mapping on the shape data.

Fifth, processing for inputting the ground height difference to the shape data. Characteristic of the first embodiment of the present invention,
The texture expression processing of the third building and the fifth height difference input processing will be described.

As a method of expressing the texture of a building, there is a method of attaching a texture corresponding to the material to a polygon constituting an outer wall of the building. In this case, the problem is how to represent the texture. For example, when a window or the like of a building is expressed with a texture using a texture, the expression becomes coarser as the three-dimensional city is enlarged. In this case, for example, when used in an in-vehicle navigation system, the texture expression changes as the vehicle travels, which is unnatural. Therefore, in the first embodiment of the present invention, such inconvenience is avoided by configuring windows and the like with polygons different from the polygons of the outer wall of the building. In addition, how to create the texture is also a problem, but at the time of the survey, the image data of the wall of the building (for example, photos of the tiles and bricks that make up the wall) were obtained with a digital camera, and this image data was It is convenient to use. Since the polygon of the outer wall of the building is different from the polygon of the window etc., it is easy to repeatedly paste the image data of the optimal conditions to express the texture, for example, the image data taken relatively close A realistic texture can be obtained.

Next, a process for inputting a height difference will be described. Here, the height difference means the height of the site itself. From the viewpoint of efficiency, it is desirable that the basic three-dimensional city data have no difference in elevation, and even if this assumption is made, there is no problem in most cases. However, there is a need for a more precise and realistic three-dimensional city database. For example, in a car navigation system or the like, the closer to the actual state of the ground surface, the more realistic the expression. Therefore, in the first embodiment of the present invention, it is possible to input a height difference as an option.

According to the result of preparing and evaluating a computer graphic screen, when the viewpoint is directed in the inclination direction (for example, when the road is on a slope and viewed from the viewpoint of a driver traveling on the road): At a tilt of 100, little difference from the plane was observed, but at a tilt of 1:20, a clear difference appears between the flat screen and the tilted screen. It was found that the level reached a level that could be discriminated by the naked eye as being inclined. Further, when the road is inclined in the transverse direction, the state can be determined even with a slight inclination. On the other hand, in the bird's-eye view image, only slight distortion appears, and it is understood that there is almost no need to provide a level difference from this viewpoint. Since the detailed description of the expression of the height difference has been made, the result of the study will be described at the end of the first embodiment.

In the actual input, the input is made on the basis of the road intersection. First, the advantage of using the road intersection as a reference is that, in many cases, the height reference is concentrated on the intersection, so that it is easy to input the height described on the map. In addition, by using the intersection as a reference, the width direction of the road near the intersection is always horizontal,
This is because it is easy to use as two-dimensional city data. Also, the position of the road is very high in this city data.

Next, the modeling procedure of the height difference will be described with reference to FIG.

A plan view is created based on the sketch (S4
0). This plan view can use the created two-dimensional data. A road board covering the entire area is created (S41). The boundary of the area is selected based on another area, and the protruding portion is cut (S42). Lines are inserted so that intersections of roads are polygonal (S43). The above steps S40 to S43 are processing for creating a plan view. By the processing of steps S40 to S43, for example, a plan view as shown in FIG. 17 is obtained. This figure shows an example of a block separated by two roads orthogonal to each other, which is the simplest case. Code 13
0 is an intersection, 131 is a road, and 132 is a site.

The following precautions should be taken when creating the plan view. First, the road on the premises should be treated as a sidewalk. There may be a case where there is a road in the site 132 in one block, but this road is not treated as the above processing or the road shown in FIG. This is because the processing is simplified and the work efficiency is improved. In this case, the quality of the image viewed from the viewpoint along the road 132 is not significantly affected, and the accuracy as the three-dimensional city data is reduced. There is no problem. Second, the curb of the road must be handled in an unbroken ring.
This is because the work efficiency can be improved by reducing the number of input points. In addition, a line is newly inserted on the road boundary line while inserting a line so that an intersection portion such as a T-shaped road becomes polygonal. Through these processes, for example, a plan view of the intersection as shown in FIG. 18 is obtained. In addition,
In many cases, the reference point for the height input of the intersection, which will be described later, is on the side of the sidewalk (inside the curb).
The relationship between the road 131 and the curb 133 is as shown in the figure.

Next, the height of each intersection is input based on the map (S44). In many cases, a reference point for surveying is provided at an intersection, and the height is input using this reference point.

A road and a site are triangulated (S4).
5). When the heights of the four vertices of the road 131 and the site 132 are input, it is conceivable that these four vertices are not on the same plane. Then, the road 131 and the site 132 cannot be handled on a plane, which is inconvenient.
These are divided by a plurality of triangles so that 32 can be treated as a plane. In FIG. 19, a dividing line of the triangulation is indicated by reference numeral 134. In the normal case, intersection 1
30 is treated as a plane, and triangulation is not performed. This is because, in practice, intersections are almost always planar, and it is more appropriate to treat them as planes. However, in the case of a complicated intersection such as a three-way intersection or a five-way intersection, triangulation may be required. For example, in the case of a three-junction as shown in FIG. 21, it is desirable to perform triangulation by two dividing lines 134.

FIG. 20 is a sectional view taken along the line AA ′ of FIG. The intersection (between AB in the vertical sectional views 19 and 20) is a plane, but is between intersections (there is a slope between BDs). The slope changes at the point C during this period, due to the influence of triangulation. Next intersection (same,
(Between DEs) is a plane, but has an inclination. As can be seen from this figure, the above processing can express the height difference of the road including the intersection. Such an expression is very effective, for example, when performing a simulation of driving with a car along a road, and can provide a realistic image from the driver's viewpoint.

Next, the object created on the plane is started up and extracted from the road portion. Further, for selecting the height position of the building, the plane of the building is extracted in the same manner as above (S46).

All data other than roads and curbs are raised by a fixed amount, for example, 20 cm (S47). Normal,
This is because the site is slightly higher than the road. In addition, by processing in this way, if the road and the site are at the same height, it may be confusing as to which material (texture) should be expressed on the computer processing,
It is also to raise the site a little. In addition, since it is unnatural if the amount of pulling up is too large or too small, 10 cm to 2 cm
About 0 cm is appropriate.

In order to match the boundary with the raised portion,
The curb is raised 20 cm (S48). As a result of this processing, the step between the road and the site is eliminated, and it is not unnatural.

A height input process is performed by the processes in steps S44 to S48 described above. In this height input processing, in order to connect the areas naturally, it is desirable to refer to road data of another area for inputting the height of the boundary between the areas.

Next, a building is created (S49). For this, the created three-dimensional data can be diverted. Further, the height position is adjusted to the selected plane, and the building is arranged with the portion having the lowest height position as 0 (S49). At this time, even if the site is inclined, the building shall be arranged vertically so as not to be inclined.

The completed data is stored for each address in the same manner as usual (S50).

The following points should be noted in the above building creation processing. Plane of building used for work is removed. This is because the sloping site is unnatural on the building floor. If the building has an entrance, the entrance is set to 0, and the part floating from the site is processed by extending the building in the minus direction. The work area for creating the height difference is in units of area. The storage is performed for each address as in the past, but the road is stored separately for each area.

1.3 Data Representation The above investigation step and modeling step are the basic procedure for creating three-dimensional city data. These data are centrally managed and become a basic “shape database”. When this is converted into an image viewed from a predetermined viewpoint, an intuitive video is obtained.

Further, in consideration of conversion to various uses in actual operation, various information is added to the “shape database” to aim at a more sophisticated expression, or conversely, a simplified and compact database is created. It is possible to aim.

Examples of these various types of databases are shown below.

(1) Shape database The data amount is 3.4 MB, the number of polygons is 13,400 polygons, the number of creation days is six days for modeling, and one day for setting. The calculation time is 3 hours, but is a case of 2048 × 1536 pixels. Commercially available F as rendering software
ormZRenderZone ™ was used. As described above, since the shape, window, and roof can be expressed from the photograph of the survey, the image of the townscape and the building can be expressed. In addition, by simplifying the expression without forming the details, the enormous amount of data is kept to a minimum and the enormous work time that would be spent on it is reduced.

(2) Precision level (shape database subjected to ordinary texture mapping) Data amount is 60 MB, polygon number is 98,000 polygons, creation time is 14 days for modeling, and 3 days for setting . The calculation time is 32 hours, provided that it is 2048 × 1536 pixels. A commercially available PERSONALLINKS (trademark) was used as rendering software. Shape details such as sashes, wall irregularities, and entrances, as well as texture expressions for each material are used, so they can withstand landscape evaluation simulations. It can be used not only for city data but also for the entertainment field. Further, it can withstand various viewpoints in terms of image quality. In particular, there is no problem in image quality even at the eye level viewpoint. However, (1) modeling time (especially the expression of details such as sashes), creation of textures, and texture setting take an enormous amount of time compared to the shape database.

(3) Shape simplicity / texture emphasis Data amount is 3.9 MB (shape data), 16.8 MB
(Image data), the number of polygons is 50,613 polygons,
The number of days to create is 2 days for modeling, 3 days for setting (including photography and texture editing), and calculation time is 5 hours 45
Min, but 2048 × 1536 pixels.
FormZRende commercially available as rendering software
rZone ™ was used. Although real photos are used as textures, there is reality, but photos including windows, decorations, and colors of the entire building must be taken without distortion, and taking and editing these photos for mapping is difficult and time-consuming. In addition, there is a disadvantage that a large amount of memory is required for rendering, which takes a long calculation time.

(4) Shape precision + color expression, partial mapping The amount of data is 55 MB, the number of polygons is 98,000 polygons, the number of creation days is 14 days for modeling, 1.5 days for setting,
The calculation time is 28 hours, in the case of 2048 × 1536 pixels. PE that is commercially available as rendering software
RSONALL INKS ™ was used. Since a landmark-like building and signboard can be represented by partial mapping, the displayed location can be intuitively grasped. However, the modeling time (especially the expression of details such as sashes) increases. Further, there is a problem that a detailed photograph is required at the investigation stage, which takes time for the investigation, and that it is difficult to set the color because the color is determined from the photograph.

(5) Shape precision + color expression, no mapping Data amount is 51 MB, polygon number is 98,000 polygons, creation time is 14 days for modeling, 1.5 days for setting,
The calculation time is 24 hours, provided that it is 2048 × 1536 pixels. PE that is commercially available as rendering software
RSONALL INKS ™ was used. Compared with the case (4), the amount of data is reduced due to no mapping, but the modeling time is still long. Further, there is a problem that a detailed photograph is required at the investigation stage, which takes time for the investigation, and that it is difficult to set the color because the color is determined from the photograph.

(6) Only rough irregularities in the shape The data amount is 1.8 MB, the number of polygons is 8,700 polygons, the number of creation days is 2 days for modeling, half a day for setting, 2 hours for calculation time, but 2048 × 1536 pixels Is the case. FormZR commercially available as rendering software
EnderZone ™ was used. You can only express the rough shape that can be understood from the picture, but the work time and data volume will be reduced. However, it cannot express the unique atmosphere of buildings and towns due to the texture.

(7) Box-shaped data amount is 0.55 MB, the number of polygons is 4,500 polygons, the number of creation days is one day for modeling, half a day for setting, and 1.5 hours for calculation time, but 2 hours.
This is the case of 048 × 1536 pixels. FormZRenderZone commercially available as rendering software
(Trademark) was used. Although it can be created with a minimum amount of data and time, the shape and atmosphere of the building are completely unknown.

There is a trade-off between the amount of work and the amount of data and the quality and accuracy of an image that can be expressed. The above (1)-
A comparative study of (7) reveals that the (1) shape according to the first embodiment of the present invention is the most excellent in terms of the balance between the amount of work and the amount of data and the quality and accuracy of expressible images. It was a database. The requirement for a three-dimensional city database is, for example, to roam freely in a three-dimensionally represented city in the virtual reality world. To meet such a requirement, a simple box or uneven representation is not enough. The expression of the details of the building is necessary. Even when creating a more precise three-dimensional city database by pasting the texture, (1) efficient work is possible based on the shape database. Therefore, (1) the shape database can be said to be the basis of various three-dimensional city databases.

In the above description, the case of creating a three-dimensional city database for outdoor is taken as an example. However, the method of Embodiment 1 of the present invention is also applied to the case of creating an indoor three-dimensional city database. it can. For example, based on a plan view of each floor of a certain building, the two-dimensional input (S1) of FIG. 1 is performed, and the height of furniture, fixtures, and other objects is determined (S2) and photographing (S2) at the site.
Perform 3). In this case, if the height of the floor is constant, the height may be set based on this, so that the investigation is easier than in the case of outdoors. Then, three-dimensional input (S4, S5) is performed based on the survey result.

By linking the outdoor database and the indoor database, it is possible not only to walk around the city along the road in the virtual reality world, but also to enter the building from the road and go around the interior. it can.

1.4 Results of Study on Expression of Height Difference (1) Problems on Expression of Height Difference The “height difference” as used herein indicates the height of the site itself. Since it is called three-dimensional city data, a height difference is an inevitable problem, and its significance relates to the entire city data. However, on the other hand, it has not been clarified about its value, that is, how much the actual height difference should be reflected in the three-dimensional city data, in connection with efficiency improvement. Therefore, the validity of the height difference, that is, whether the height difference is really necessary was examined. Regarding the verification method,
A sample image in which a height difference is actually input is used, and the sample image is compared with an image of city data input in a plane. In addition, we verified the alignment with the mountains around the city when it was created on a plane.

The elevation difference input method used in this verification is the above-mentioned “method of inputting the elevation difference based on the road intersection”. Although there are other creating methods, for example, using contour lines and meshes, these methods are obviously inappropriate in consideration of efficiency, which is the biggest problem of height difference, and thus this method was adopted.

(2) Study on Effectiveness of Height Difference A. Height difference of still images in a narrow range (one area) Modeling test data assuming relatively flat terrain (for example, the area around Kasumigaseki in Tokyo) was constructed, and based on this, the following six types of viewpoints were used. A total of 12 types of images in which the presence or absence of a height difference was set were created, and verification was performed by comparing the images. FIG. 22 is an explanatory diagram of the viewpoint and the line of sight. In this figure, reference numeral 140 denotes a viewpoint, reference numeral 141 denotes a line of sight, reference numeral 142 denotes a horizontal road surface, reference numeral 143 denotes an inclined road surface, and reference numeral L denotes a horizontal line for reference. Reference numeral 140a corresponds to the following viewpoints B and D,
Reference numeral 140b corresponds to the following viewpoints A and B.

Viewpoint A 1: Image from a descending inclined viewpoint of 1: 100 (FIG. 23: Left side has a height difference, right side has no height difference) Viewpoint B Image of a tilted viewpoint rising from the reverse position of Viewpoint A (FIG. 24: The left side has a height difference, and the right side has no height difference. Viewpoint C: Image from a descending inclined viewpoint of 1:20 (FIG. 2)
5: There is a height difference on the left side, no height difference on the right side. Viewpoint D Image of an inclined viewpoint rising from the reverse position of viewpoint C (FIG. 26: Left side has a height difference, right side has no height difference). Images from different viewpoints (FIG. 27: Height difference on the left side, no height difference on the right side) Viewpoint F Bird's-eye view image (FIG. 28: Height difference on the left side, no height difference on the right side) 1 verified with viewpoints A and B : At an inclination of 100, there is almost no difference from the plane. In particular, when the viewpoint B is inclined upward, it is difficult to determine the presence or absence of the inclination. However, when the inclinations of the viewpoints C and D become 1:20, a clear change appears in the difference. Both viewpoints showed a great difference in the landscape, indicating that the level reached a level that could be discerned even by the naked eye.

[0144] Further, a viewpoint E in which the inclination of the right and left is verified.
In, the verification results within the prediction range were obtained. Despite the verification from the viewpoint C position, the difference is slight, but the inclination can be determined.

At the viewpoint F, as in the previous case, only slight distortion appears. From this viewpoint, the necessity of a desired level difference cannot be proved.

B. Height difference of still images in a wide area (4 areas) Using a wide range of modeling data assuming four areas around a relatively large city (for example, Sapporo) with a population of about 1 million and mountains around it, A total of two kinds of bird's-eye images with or without presence were created, and verification was performed by comparing the two.

By looking at the height difference over a wide range,
Expecting a large difference in the landscape, it was proved to be more difficult to distinguish between the two than a still image in a small area.
The reason is that especially in the case of a well-developed city, the height difference is large only in a very limited area around the mountain, and as a whole (four areas) does not reach a height of about 10 m.

C. Height difference of video Using QuickTime VR (trademark), the presence or absence of a height difference is set using modeling data of the above city.
A total of two types of 60 ° moving images were created and verified by comparing the two.

Although the effectiveness of the height difference could not be demonstrated in a still image, a difference in the height difference was expected in a moving image. However, no significant difference in elevation was observed here. After all, moving images are merely extensions of still images, and the need for such height differences in general urban areas could not be demonstrated.

(3) Verification of alignment with mountains when created on a plane When it is considered that three-dimensional city data is created on a plane, inconsistency in boundaries with mountains is a problem that inevitably occurs. From the viewpoint of unity, it is desirable to maintain the status of the urban area as it is and to process the mountain in some way to ensure consistency. Create city boundaries as the lowest altitude line of the mountain. The height is as follows: B. Setting that is included in the lowest position of the road intersection at the boundary seen in the current state map B. Setting according to the average position of the road intersection at the boundary of the current state map The verification is divided into three patterns that are set according to the highest position of the road intersection at the boundary seen in the current state map.

When the boundary was set at a low position, the contradiction at the low position of the mountain portion was alleviated or, on the contrary, at the high position, the slope became extremely steep, making it unsightly. When the boundary is set at a high position, there is no apparent inconsistency, as can be seen from the fact that the gentle slope described above is difficult to distinguish as an image. When the boundary is set at the average position, it seems at first glance to be effective, but there are inevitably steep slopes and cliffs, and it is not possible to determine that it is useful considering the difficulty of calculating the average value.

In conclusion, it seems prudent to set the boundary at the highest point of the road intersection. However, this does not solve all problems. This method can withstand the ignored height difference up to about 50 m,
If it is more than m, there is a possibility that a large difference occurs in the landscape.

In order to overcome this problem, a certain degree of slope is formed with a height difference, but it is considered that it is desirable to make the range of the city data itself along the contour lines as much as possible.

(4) Summary of Height Difference As described above, no significant difference was recognized in the height difference between still images and moving images. Considering the creation efficiency and the low frequency of use of the terrain itself that has a height difference, it can be determined that priority should be given to a flat surface. At present, the conclusion is that, although the height difference is completely different from the data itself, it has the property that it is added to the plane in the production, and the versatility of the city data itself is taken into consideration. Therefore, it is reasonable to treat it as an option that the basics are created on a plane and the height difference is created as needed.

[0155] Even if the image is worthless, the necessity arises in the case of a tourist city where hills are the main object, or in the case of data usage such as analysis. In the future, if higher-precision three-dimensional city data is required, it is considered that the height difference expression will be important.

Embodiment 2 of the Invention Embodiment 1 of the invention
In the investigation step in section 1.1, the investigation was conducted from many points as shown in FIG. However, considering that the cost of investigating large cities is enormous, it is desirable that the points of investigation be as small as possible. Therefore, in a second embodiment of the present invention, a description will be given of a research method that can reduce the number of points to be researched.

The survey points according to the present embodiment are only at the four corners of the block as shown in FIG. 29, and are only one-third that of FIG. That is, block 110 in FIG.
From the outside of the vertex in the directions indicated by reference signs A to D, and photographing is performed. In this method, the height is basically determined only for the building at the corner of the block, and for other buildings, the height is obtained from the ratio on the photograph based on the building at the corner.

To determine the height from the ratio on the photograph,
For example, processing is performed in the following procedure.

It is assumed that an image as shown in FIG. 30 has been obtained. Since the height H of the foremost building can be known by measurement, this is used as a reference. For example, on the image, the line of the roof of the building in front is extended, its height (the number of pixels) is measured, and the heights x1 and x2 of the building are obtained based on this. In the example of FIG. 30, if the number of pixels corresponding to the heights x1, x2, y1, and y2 of the building is xx1, xx2, yy1, and yy2, x1 =
H · xx1 / (xx1 + yy1) or x2 = H · x
x2 / (xx2 + yy2) Since the image of FIG. 30 is obtained by a digital camera, it is easy to count x1, x2, y1,
y2 can be determined.

To increase the accuracy in this method,
The following things need to be considered.

The distortion of the camera lens is corrected. For example, by photographing a building whose height is known in advance, a correction value that matches the actual height with the calculated height is obtained in advance, and a correct value is obtained by the correction value at the time of actual measurement. Fix it.

The height of one building is determined at a plurality of points, and the average value is used as height data. In FIG. 30,
Since the height is measured at two places for one building,
The average of these values is used as the measured value. Further, when the same building is shown in another photograph, the height based on this photograph may be adjusted. At this time, it is conceivable to weight a plurality of pieces of height data. For example, the weight of height in a distant part in a photograph is reduced, and the weight of height in a nearby part is increased.

According to the method of Embodiment 2 of the present invention,
It is sufficient to investigate one block for each corner, for example, four places for a square block and three places for a triangular block, and the number of places to be investigated is extremely small (for example, one third). Below), work efficiency is remarkably improved.

Embodiment 3 of the Invention Embodiment 1 of the invention
Then, as shown in FIG. 3, a survey was performed using a tripod on which a ranging camera and a digital camera were attached. By the way, in order to improve the working efficiency, it is desirable to use a device that allows the worker to work while holding it by hand without using a tripod. Therefore, a device for obtaining three-dimensional city data will be examined.

As can be seen from the description of Embodiment 3 of the present invention, the functions and performances of the equipment necessary for this investigation are as follows. First, the ability to measure the distance to the building,
The ability to measure angles to measure the height of the building, and to be able to obtain digital images of the building.

As a device that satisfies the above functions, a device that is used in surveying and combines ranging and a digital camera at a hand level capable of measuring an angle can be considered. The following are commercially available simple surveying instruments. The height is displayed directly on the scale from the distance and angle.
Melais altimeter (angle measurement accuracy ± 1%), fixed point 15,2
With a distance meter of 0, 30, and 40m. Infrared distance meter (Light
SPEED400 (trade name)), measurable distance 15 to 4
00m (distance measurement accuracy ± 1m). Laser distance meter, measurable distance 0.2-30m (distance measurement accuracy ± 3mm). Ultrasonic rangefinder, measurable distance 0.5-18m (± 1%).
Hand level with level and altimeter, accuracy of 0.5 degrees, height calculated by distance and angle.

If a digital camera with an improved rangefinder is used, ranging can be used instead. Furthermore, if the angle of any point can be obtained based on the image of the digital camera, the angle measurement function becomes unnecessary. For example, an electric level and an inclinometer are provided in the camera so that the elevation angle can be measured. Alternatively, the angle is measured in advance for each pixel, and the angle is obtained directly from the pixel. In this case, a specific pixel must always coincide with the horizontal line. An example is shown in FIG. The horizontal line L is automatically displayed on the screen of the finder, and this is matched with the actual horizontal line. Then, the measurement point P of the building B is designated using a cursor or the like. The angle (height) can be automatically known by measuring the pixel position of the measurement point P.

This functional block is shown in FIG. In this figure, in the electronic viewfinder 30b of the digital camera 30a, a horizontal line is displayed by an electric level 30d, and a cursor is moved by a pointing device 30e such as a joystick or a mouse. The image data and the information on the pixel position of the measurement point P are output to the outside via the output unit 30c.

As a device most suitable for the investigation in the first embodiment of the invention, a device based on a digital camera and having a distance measuring function and an angle measuring function added thereto can be considered. If all the measurement data is digitized, it is convenient in the subsequent processing.

Embodiment 4 of the Invention Since the measuring device described in the third embodiment can output digital information, the working efficiency can be further improved by connecting the measuring device and the host computer via a communication line.

For example, as shown in FIG.
A measuring device 30 that outputs angle data and distance data is connected to a notebook computer 31. Laptop 31
Calculates the height h for each building by the above-described method, and transmits the image data, the height h, the block information, and the building information using the PHS. The block information is information (for example, a number) for specifying a block, and the building information is information (for example, a number) for specifying a building in the block. These pieces of information are set when two-dimensional information is input, and are stored in the hard disk of the notebook computer 31. In an actual survey, the survey data specifies the building to be measured while looking at the two-dimensional information, so that the survey data matches the block information and the building information.

The image data received by the modem 33,
The height h, block information, and building information are input to the host computer 34 and stored in the database 35. Thereafter, it is used for the above-mentioned modeling process.

By connecting the survey device and the host computer online in this way, not only the survey efficiency is improved, but also errors in the survey on site are reduced, and a highly accurate survey is possible. In addition, since data can be simultaneously received from a plurality of survey devices, the speed of the survey is increased. Furthermore, since there is no restriction on the location of the survey, a single host computer can create a three-dimensional city database in Japan and in any city in the world using the Internet.

Embodiment 5 of the Invention The height information of the building may be obtained by remote sensing using a high-resolution satellite, which is different from the above method. For digital analysis plotters, high-resolution satellite images, which are cheaper than aerial photographs, can be used as the orientation images. This image is
Currently, it cannot be used because of its relatively low resolution (± 5 m), but it can be used to some extent for tall buildings. In the future, if a high-resolution satellite with an accuracy of at least ± 0.1 m becomes available, it can be used.

Embodiment 6 of the Invention An operation method of the three-dimensional city database produced as described above will be described. In order to maintain and operate city data, a general-purpose database, that is, a city database that can support various applications, is required. And a software rendering-based method emphasizing image quality.

A method using a real-time database is as follows.
The operation procedure is as follows.

[0177] 1. System data according to the operation mode
1. Base design (GIS design, character information, GPS setting, texture expression, etc.) Operation test of test sample (temporary embedding of data) 3. Full integration of data (shape, texture, texture) 4. Test operation (requires hardware / software with relatively high processing capacity from here) Main operation 6. Maintenance The software rendering method involves the following operation procedure. 1. System data according to the operation mode
1. Base design (texture expression, embedded design) test·
2. Sample operation test (temporary embedding of data) 3. Full integration of data (shape, texture, texture) Trial operation 5. Main operation 6. Maintenance It should be noted that the final software to be selected in software rendering must be selected in consideration of the enormous data integration efficiency, the compatibility of algorithm / mapping data, and the rendering quality.

Note that the three-dimensional city database operated as described above may be configured, for example, to be available online.

Embodiment 7 of the Invention The three-dimensional city database operated as described above is versatile, can be ported to other systems, can be linked to various devices, and can be applied to various applications.
For example, the following can be considered.

(1) Three-dimensional three-dimensional map (2) Three-dimensional car navigation FIG. 33 shows an example of a screen provided by this application.
Shown in The car navigation system determines the viewpoint and the line of sight based on the position information obtained from the position sensor and the traveling direction obtained from the direction sensor, and as shown in FIG. 33 viewed from the viewpoint and the line of sight based on the three-dimensional city database. Display the screen. At the same time, information on the current address, the situation in the traveling direction, and the situation on the left and right is also displayed. Since the screen of FIG. 33 is the same as the actual scenery, it is easy for a beginner to understand and use. Also, the display may be configured to switch between a three-dimensional display as shown in FIG. 33 and a normal plan view display.

(3) Search system (4) Disaster prevention
(5) Shading simulation This application describes how to find the shading area.
As shown in FIG. If the position of the sun S and the position and height of the building B are known as shown in FIG. 34 (a), a shaded line can be drawn. The position of the sun S is specified by the season, and the position and height of the building B are obtained from the three-dimensional city database. Based on this line, a shaded area projected on the ground surface can be specified as shown in FIG. If the sun is at the position S1, a shadow K1 is generated, and if the sun is at the position S2, a shadow K2 is generated. When the sun is continuously moved from S1 to S2, the trajectory of the end of the shade is represented by the symbol L.
By using a three-dimensional city database, complicated shaded conditions in a city can be automatically and accurately determined. (6) Simulation of radio interference FIG. 35 shows how to obtain the radio interference status in this application. There are two types of radio interference: a case where a strong radio wave such as a microwave is blocked by a building, and a case where a radio wave having a relatively long wavelength has a multipath caused by interference between a straight wave and a reflected wave reflected by the building. is there. In FIG. 35, an area AREA indicates an area in which radio waves from the transmitting station T are blocked by a building, and a point P indicates PATH1 and PTH1.
An area where a multipath occurs with ATH2 is shown. In any case, these can be automatically obtained by using the three-dimensional city database. In particular, by using the building height information of the three-dimensional city database, a so-called three-dimensional simulation can be performed in consideration of the building height. For example, it is possible to consider the diffraction of radio waves in the height direction of a building, and to consider the interference of radio waves over the entire side surface of a building, that is, to consider the height. Therefore, a more precise simulation can be performed. (7) Urban life simulation (8) Moving object position display system for people and cars in cities and buildings (9) Other numerical simulations (various object simulations using shape data) (10) ) Disaster prevention support system (11) Application to search guide system for exposure to light, simulation before travelling (12) Use for security systems of security companies, etc. (13) Local industry support system (14) Underground buried object management system (15) Real estate survey management system (land use to tax management, etc.) (16) Market research support system (17) Traffic control system (18) Use as analysis data of radio interference and shade (19) To 3D car navigation system Embodiment 8 of the Invention As a display means of the three-dimensional city database operated as described above, in addition to a normal CRT and a liquid crystal display device, in particular, in a VR (virtual reality) -related application, a projector or an HMD (head mount) is used.・ Display) can be considered.

Embodiment 9 In addition to using three-dimensional city data alone, advanced data services may be provided in combination with other data. For example,
A system that simultaneously displays various information about the building together with the building can be considered. Some conventional maps have information such as the name of the house owner written on the floor plan of the building, but there is no problem if it is a single-story general house, but if you try to display the same information on high-rise buildings, the display will be complicated, It was hard to use. In this regard, if three-dimensional display is performed by computer graphics using three-dimensional city data, various searches can be made for high-rise buildings, and the space can be visually grasped, which is very easy for the user to use. It will be. It can perform space recognition that cannot be grasped simply by the expression using characters or flat maps.

FIGS. 36 to 4 show examples of such a system.
Explanation will be made using 0. FIG. 36 shows a schematic configuration of this system. 5 in that it has a CPU 10, a CRT 11, and a keyboard 12, but differs in that it has two hard disks 16 and an attribute database 16b in addition to a map database 16a. Both are related to each other, and when a part of the buildings included in the three-dimensional city data is searched, the corresponding attribute data can be searched. These databases can be constructed on the same hard disk 16 as shown in FIG.

The attribute database 16b is, for example, as shown in FIG.
The contents as shown in are stored. This database is organized by building name or its identification code included in the three-dimensional city data, and further organized by floor of the building. Therefore, with respect to an arbitrary building, it is possible to display attribute information corresponding to the entire building or each floor. In order to arrange the positional relationship within the floor, it is conceivable to display tenant positions in east, west, north and south as shown in FIG. In addition, a method of defining a positional relationship between adjacent tenants is also conceivable.

In order to use the shape data of buildings and facilities created by the three-dimensional city data for various purposes such as retrieval, the following items may be added as attribute information thereof.

・ Address lot number ・ Building use ・ Building structure scale ・ Building completion date, building history information (extension, renovation, renovation, etc.) ・ Store, tenant, resident information ・ Building owner ・ Real estate valuation About the example of the expression form in the form,
This will be described with reference to FIGS. FIG. 38 (a)
An example in which a so-called “speech balloon” (comment box) is used to display information on a certain five-story building B facing a road R will be described. The display of the attribute information is displayed as needed by the user or automatically by a program. In this case, together with the attribute information such as the building structure scale of the building itself, the building completion date, and the building history information, the attribute information is sequentially displayed for each of the first to fifth floors.
FIG. 38B shows an example in which attribute information is displayed on the display of the building itself. In this figure, the display of the attribute information of the building itself is omitted. The method of FIG. 38A is excellent in that the appearance of a building and its attributes can be simultaneously expressed, while the method of FIG. 38B is excellent in that information on any floor can be obtained intuitively. Whether the method of FIG. 38 (a) and the method of FIG. 38 (b) are used alone or in combination,
either will do.

When the attribute is displayed using the three-dimensional city data, the position of the user's viewpoint can be freely moved, so that the information can be easily used and the information can be easily grasped. For example, when the attribute information of the fifth floor portion of the building B is displayed as shown in FIG. 39 (a), in order for the user to obtain detailed information of this portion, the viewpoint must be changed to the building B in the three-dimensional city data. To enlarge the 5th floor. Then, more detailed tenants T1, T
2 is displayed. The attribute information in FIG. 39A is not the same as the attribute information in FIG. 39B. For example, the former is general information, and the latter is detailed information.
FIG. 37 shows an example of the detailed information, but outline information associated with the detailed information is also prepared. When the viewpoint is moved along the building B, it is displayed as shown in FIG. 39 (c), and the hidden portion can be seen in FIG. 39 (b).

A display mode as shown in FIG. 40 is also conceivable. The appearance of the building B is expressed in a transparent or translucent state so that the inside can be seen through. Internal tenant T1
The arrangement of T3 is clear at a glance.

The display modes shown in FIGS. 39 and 40 are very excellent in that detailed information can be grasped and their positions can be intuitively known.

Embodiment 10 of the Invention A three-dimensional three-dimensional city map may be displayed, and a two-dimensional map of the city may be displayed at the same time. FIG. 41 shows an example. FIG. 41A is a display screen of the aforementioned three-dimensional city map,
FIG. 2B is a plan view showing the viewpoint and the field of view of FIG. According to FIG. 6B, it can be seen that FIG. 7A is an image in the direction in which the building B is viewed from the viewpoint P.
Since the height is not well understood in the plan view, the height can be known by displaying “current position S1W4 H = 50 m” on FIG. Note that S
1W4 means a constellation on the map (for example, South 1-chome west 4-chome). A similar display is also shown in FIG. 9A, so that the type, date, and time of the image can be known.

By combining with the sunshine simulation technology, the sun altitude information can be reproduced by a computer graphics image. In addition, by defining artificial lighting such as a streetlight, a neon sign, and a floodlight instead of sunlight as a light source, not only sunshine but also a night view can be reproduced.

As described above, the map screen and the computer graphics can be linked, and the current viewpoint position can be easily grasped.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say, this is done.

In this specification, means does not necessarily mean physical means, but also includes a case where the function of each means is realized by software.
Further, the function of one unit may be realized by two or more physical units, or the function of two or more units may be realized by one physical unit.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a method for generating three-dimensional city data according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram of a method for measuring the height of a building according to Embodiment 1 of the present invention.

FIG. 3 is a schematic diagram of a measuring device used in the method according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a measurement position and a direction in a block according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram of a computer used in the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of site shape data according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of a building of rank A according to the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of a B-rank building according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram of a C-rank building according to the first embodiment of the present invention.

FIG. 10 is an example of a building of rank A according to Embodiment 1 of the present invention.

FIG. 11 is an example of a B-rank building according to Embodiment 1 of the present invention;

FIG. 12 is an example of a C-rank building in Embodiment 1 of the present invention.

FIG. 13 is a flowchart of creating two-dimensional data according to the first embodiment of the present invention.

FIG. 14 is a flowchart of modeling of three-dimensional data according to the first embodiment of the present invention.

FIG. 15 is a flowchart of modeling of special terrain according to the first embodiment of the present invention.

FIG. 16 is a flowchart of modeling of a height difference according to the first embodiment of the present invention.

FIG. 17 is an explanatory diagram of modeling of a height difference according to the first embodiment of the present invention;

FIG. 18 is an explanatory diagram of modeling of a height difference according to the first embodiment of the present invention.

FIG. 19 is an explanatory diagram of modeling of a height difference according to the first embodiment of the present invention;

FIG. 20 is an explanatory diagram of modeling of a height difference according to the first embodiment of the present invention;

FIG. 21 is an explanatory diagram of modeling of a height difference according to the first embodiment of the present invention.

FIG. 22 is an explanatory diagram of evaluation of a height difference according to the first embodiment of the present invention.

FIG. 23 is an example of a height difference evaluation screen according to Embodiment 1 of the present invention;

FIG. 24 is an example of a height difference evaluation screen according to Embodiment 1 of the present invention;

FIG. 25 is an example of a height difference evaluation screen according to Embodiment 1 of the present invention;

FIG. 26 is an example of a height difference evaluation screen according to Embodiment 1 of the present invention;

FIG. 27 is an example of a height difference evaluation screen according to Embodiment 1 of the present invention;

FIG. 28 is an example of a height difference evaluation screen according to Embodiment 1 of the present invention;

FIG. 29 is an explanatory diagram of measurement positions and directions in a block according to Embodiment 2 of the present invention.

FIG. 30 is an explanatory diagram of a method for measuring the height of a building according to Embodiment 2 of the present invention.

FIG. 31 is an explanatory diagram of a method for measuring the height of a building according to Embodiment 3 of the present invention.

FIG. 32 is a configuration example in which a measuring instrument and a host computer according to Embodiment 4 of the present invention are connected by a communication line.

FIG. 33 is a screen example of an application (car navigation) according to the seventh embodiment of the present invention.

FIG. 34 is an explanatory diagram of an application (simulation of a shaded area) according to the seventh embodiment of the present invention;

FIG. 35 is an explanatory diagram of an application (a radio wave interference situation simulation) according to the seventh embodiment of the present invention.

FIG. 36 is a schematic block diagram of an application (a system for displaying three-dimensional attribute information) according to Embodiment 9 of the present invention;

FIG. 37 is an example of an attribute database according to Embodiment 9 of the present invention.

FIG. 38 is a screen display example according to the ninth embodiment of the present invention.

FIG. 39 is a screen display example according to the ninth embodiment of the present invention.

FIG. 40 is a screen display example according to the ninth embodiment of the present invention.

FIG. 41 is a screen display example according to the tenth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Distance measuring device (ranging) 102 Digital camera 103 Tripod with level and protractor 120a Exterior wall of a building of rank C 120b Rooftop of a building of rank C 120c Doorway other than glass of a building of rank C 120d Window of a building of rank C 120e Slope roof of building of rank C 130 Intersection 131 Road 132 Site 140 View point 141 View line 142 Horizontal road surface 143 Inclined road surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Kinmi 10-2-7 Kita 2-Jo Nishi, Chuo-ku, Sapporo, Hokkaido In-wall Co., Ltd. No. 2-7 in the Wall Co., Ltd. (72) Inventor Naohiro Tashita 2-7-7 Kita 2-Jo Nishi, Chuo-ku, Sapporo, Hokkaido

Claims (11)

[Claims] 1. An investigation step of collecting data including height information of a building in a city, a modeling step of performing a three-dimensional modeling of the building based on the collected data, and a data generated by the modeling step And an integrating step of generating a three-dimensional city database by incorporating a database. 2. The method according to claim 1, wherein the investigating step includes a height determining step of measuring a distance and an angle in order to calculate a height of the building, and a photographing step of photographing a target building. The method for generating three-dimensional city data according to claim 1, wherein 3. The investigation step is performed on a block including a plurality of buildings, and the investigation of each building is performed from the direction of the corner for a corner building, and the part is investigated for a characteristic part of the building. The method according to claim 1, wherein: 4. The method according to claim 1, wherein the surveying step is performed on a block including a plurality of buildings, and the survey of each building is performed only at a corner of the block. 5. The method according to claim 1, wherein in the investigating step, the building is photographed using a digital camera, and the height of the building is determined based on pixel data of the photographed image. 3D city data generation method. 6. The method according to claim 1, wherein the modeling step distinguishes modeling according to the importance of the building. 7. The method according to claim 1, wherein in the modeling step, a height difference is provided in a polygon on a site other than the building. 8. An input unit for receiving data including height information of a building in a city, a modeling processing unit for performing three-dimensional modeling of the building based on the input data, and a model processing unit generated by the modeling processing unit. Storage means for storing data, wherein the modeling processing unit reproduces the modeling of the building accurately in the database, which is important for increasing the accuracy and realism of a predetermined three-dimensional city database. A-ranked buildings that need to be updated and are relatively important to enhance the accuracy and realism of the 3D city database and need to be reproduced somewhat accurately in the database
A three-dimensional city data generating apparatus, wherein the three-dimensional city data generating apparatus is performed separately for a B-rank building, a building having lower importance than the A-rank and B-rank buildings, and a shape of a site other than the building. 9. A hand level for measuring an angle, a ranging for measuring a distance, a hand level for measuring a distance, and a hand level for measuring a distance, which are used for collecting data of a city building in the surveying step of the three-dimensional city data generating method according to claim 1. A measuring device for three-dimensional city data survey, comprising: a digital camera for photographing; wherein the hand level, the ranging, and the digital camera are integrally configured. 10. A digital camera used for collecting data of buildings in a city in the surveying step of the method for generating three-dimensional city data according to claim 1, wherein the electronic level and the orientation of the digital camera are used. For adjustment,
Display means for displaying a horizontal line in the viewfinder screen based on the output of the electric level, pointing means for designating a measurement point of the building, and output of photographed image data and pixel information of the measurement point A measuring device for three-dimensional city data survey, comprising: output means. 11. The digital camera further includes a ranging for measuring a distance, receives the image data, the pixel information of the measurement point, and the distance information, and determines an angle of the measurement point from the pixel information of the measurement point. A three-dimensional city data surveying measurement device including a portable information terminal that calculates and calculates the height of the measurement point from the distance information and the angle.