Map information system capable of displaying layout information

A method for displaying information and system includes the steps of displacing map data on the screen of a display unit, displaying layout data representing one or more segments of a certain floor in each of the one or more structure elements of the map data displayed on a first designated portion, on a second designated portion of the screen in response to a layout display instruction, and displaying attribute data corresponding to each of the one or more segments of the floor.

BACKGROUND OF THE INVENTION 
The present invention relates to a method of display layout data and a 
system therefore. 
The following references have been known relating to the present invention. 
These references are suitably cited in the following explanation of the 
present invention. 
Reference 1: "Map Information Expert System GENTLE", by Shimada and Ejiri, 
a preparatory draft for the Advanced Database System Symposium in 1985, pp 
93-101, Information Processing Society of Japan; 
Reference 2: "Introduction to Three-Dimensional Graphics based on C 
Language", by Shigeo Ishii, Gijutsu Hyoronsha, 1985; 
Reference 3: "Principles of Database Systems", by Ullman, J. D., Computer 
Science Press, Potomac, Mayland, 1980; 
Reference 4: "Object-oriented Programming: An Evolutionary Approach", by 
Brad J. Cox, Addison-Wesley Cop. Inc., 1988; 
Reference 5: "A multiple prospector and an Automatic Message Propagation 
Mechanism for Multi-media type Map-based Systems", by Shimade, et. al., 
Proc. Advanced Database System Symposium, 1989; 
Reference 6: "Multi-media Map Information System for Electric Power 
facilities using Automatic Selective Recognition Method", by Chikada, 
Shimada, Miyatake and Matsushima, the national meeting of The Institute of 
Electronics Information and Communication Engineers of Japan, 1988, 
SD-7-4; and 
Reference 7: "Application of Map Information--for forming regional 
appearance" by, Goji Sasada, Graphic Processing Information Center, 1983. 
As one of relevant patent applications, there is the U.S. Pat. application 
Ser. No. 07/630,328, now U.S. Pat. No. 5,210,868 dated May 11, 1993 titled 
"Method of Processing Multimedia Data in Multimedia Database and System 
Therefor" filed on Nov. 29, 1990. One of the inventors of this relevant 
application (Mr. Shimada) is also one of the inventors of the present 
application. 
Another relevant U.S. Pat. application Ser. No. 07/789,005, now pending, 
titled "Method of Three-dimensional Display of Object-oriented Figure 
Information and System Therefor" was filed on Nov. 7, 1991, based on the 
Japanese patent application No. Hei-2-299718 filed on Nov. 7, 1990. The 
two inventors (Shimada and Kawamura) of this relevant application are also 
two of the inventors of the present application. 
Still another relevant U.S. Pat. application Ser. No. 07/799,998, now 
pending, titled "Method of Managing Information and System Therefore" was 
filed on Nov. 29, 1991, based on the Japanese patent application No. 
Hei-2-329106 was filed on Nov. 30, 1990. The two inventors (Shimada and 
Chikada) of this relevant application are also two of the inventors of the 
present application. The relevant patent applications are incorporated 
herein by reference. 
In recent years, multistory buildings and underground markets have been 
developed in the centers of areas. In order to identify details of 
buildings and houses or the arrangement and location of shops and stores, 
three-dimensional information, such as the numbers of floors of buildings 
and the numbers of floors of underground markets has been employed in 
addition to conventional two-dimensional information such as provided on 
typical maps. Under such a situation, in each of public enterprises and 
architectural and civil engineering enterprises, three-dimensional map 
displays, which take account of heights of buildings as well as figures of 
the buildings above the ground surface level, have come to be required 
because the conventional two-dimensional map displays are not sufficient 
in performing works, such as facility inspections and urban designs for 
which maps are used. 
In order to meet these requirements, various kinds of three-dimensional 
bird's-eye displays using design data have already been carried out in the 
field of an architectural CAD, as shown in the reference 7. In the 
architectural CAD, data of buildings and the like are converted into 
complete three-dimensional data and stored in a data base. By using this 
data the buildings and highways can be displayed in a three-dimensional 
manner when they are to be viewed from any desired direction. 
Therefore, a method would be considered wherein various attribute data of 
the buildings having three-dimensional characteristics are displayed in 
one-to-one corresponding relation with the buildings, after the 
three-dimensional bird's-eye display is made. 
Further, a method of applying shading to the display considering a light 
source has been proposed recently, in addition to a mere three-dimensional 
display using a wire frame, so that a display having more reality has 
gradually been made possible. 
However, in application of the method shown in the above reference 7 to a 
map information system as an example of a figure information system, it is 
necessary to obtain figure data of a building as data of a complete 
three-dimensional coordinate system (x, y, z) as in the architectural and 
civil engineering CAD. Therefore, the following four problems exist. 
As the first problem, in the case of a map information system, there is a 
heavy load for displaying various kinds of attribute information in 
correspondence with figure elements on a two-dimensional display of map 
data which include a large amount of figure elements such as roads and 
house frames. Therefore it is not practical for a complete 
three-dimensional display of the map data compared with the architectural 
CAD system. In other words, it is assumed that the map data is merely 
stored in a data base which map data includes coordinate data indicative 
of figure elements of roads and buildings, and symbols for churches, 
banks, and the like, and texts for display. Therefore, in the case of 
retrieving attribute data by using a displayed building or text as a key 
for the retrieval, a z-coordinate of a height direction needs to be 
searched for route search processing and search processing within a near 
range in addition to two-dimensional coordinates (x, y). Therefore, the 
time for executing various retrieval processings is expected to become 
extremely long. 
As a second problem, in a map information system, in order to obtain 
complete detailed data of three-dimensional coordinates for buildings as 
defined in the architectural CAD system, it is necessary to obtain such 
detailed data by searching data associated with each building, resulting 
in an enormous amount of search processes. Therefore, it is almost 
impossible to completely build a three-dimensional data base for this 
purpose. 
As a third problem, when map data for a wide three-dimensional area, such 
as an underground market, is to be displayed, displays of houses and 
tenants on each floor tend to interfere with each other in many cases, as 
shown in FIG. 30, resulting in a very complicated display which is 
difficult to understand. Therefore, a detailed instruction cannot be made 
such that a part of the result of the display cannot be processed by 
designating this part by means of a mouse. 
As a fourth problem, in the case of displaying various kinds of attribute 
data on the above three-dimensional display, it is expected to be 
extremely difficult to confirm at a later stage a corresponding relation 
between buildings and an attribute. 
SUMMARY OF THE INVENTION 
The present invention has been made in the light of the above-described 
situations, and it is an object of the present invention to provide a 
method for displaying attribute data having three-dimensional 
characteristics on a two-dimensional display of map information in 
one-to-one correspondence, and a system therefor. 
It is another object of the present invention to provide a method for 
displaying layout information such as an underground shop street layout 
diagram and a tenant residence diagram which exist separately from map 
information, and a system therefor. 
In order to achieve the above objects, the method for displaying layout 
information in a map information system, includes the steps of: 
displaying map data on the screen of a display unit in response to a map 
display instruction, each of one or more constituent elements of the map 
data displayed on a first designated portion of the screen including one 
or more segments on each floor; 
displaying, on a second designated portion of the screen, the layout data 
indicative of the one or more segments of a floor for each constituent 
element, in response to a layout display instruction; and 
displaying attribute data corresponding to each of the one or more segments 
of the floor. 
As explained above, according to the attribute data display method of the 
present invention, the attribute data having three-dimensional 
characteristics can be displayed on two-dimensionally displayed map 
information in a one-to-one correspondence relation without any 
inconsistency. With this arrangement, not only the display speed is 
increased but also functional performance is improved substantially, so 
that the system provides substantial improvements to the using 
characteristics for the users. 
Also, layout information such as an underground market layout diagram and a 
tenant residence diagram which exist separate from the map information can 
be displayed so that these diagrams can completely match with the map 
data. Further, attribute data having three-dimensional characteristics can 
also be displayed so that the attribute data matches with the layout 
information in a one-to-one correspondence relation. Therefore, the 
functional characteristics for the users to use the system can be improved 
substantially. 
Furthermore, according to the present invention, attribute data having 
three-dimensional characteristics can be completely corresponded to the 
elements of a map displayed two-dimensionally, without any duplication, so 
that the retrieval or editing operation can be made completely, leading to 
a substantial improvement in the man-machine characteristics.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The map information system capable of displaying layout data will be 
explained below with reference to the attached drawings. 
The basic concept of the present invention will be explained first. 
According to the present invention, layout data such as a shop layout and 
a tenant residence layout which exist separate from map data is displayed 
in correspondence with figure elements of the map data already displayed, 
such that the layout data is completely superposed on the displayed figure 
elements by applying conversion processing of a data format to the layout 
data. By this processing, a complete one-to-one correspondence relation is 
obtained between these figure elements and attribute data having 
three-dimensional characteristics. Further, in the case of displaying the 
attribute data on the map data, it is possible to make a lateral display 
for each floor or a partially sectional display. 
In the present invention, attribute data having three-dimensional 
attributes are rearranged on a two-dimensional partial list. Accordingly, 
by converting the map data into a two-dimensional virtual exploded 
diagram, it is possible to convert the map data into a development 
elevation having a virtual format so that the three-dimensional attribute 
data has a one-to-one correspondence relation with the map data and to 
display the converted development elevation. 
Further, by fixing one axis of a three-dimensional display, a 
two-dimensional display can be made in the state that equivalent virtual 
slices are displayed for each floor. 
Next, the first embodiment of the present invention according to a map 
information system will be explained with reference to FIG. 1. FIG. 1 is a 
block diagram showing a functional structure of the map information system 
according to the first embodiment. The functional structure includes 
broadly four sections, including an operating section, a processing 
section, a data base section and a display section. The data base section 
is divided into a map data base 101 for storing map data and an attribute 
data base 102 for storing attribute data having three-dimensional 
characteristics, and each data base is stored in a file unit. When an 
operator inputs a retrieval key and an edit command from a command 
inputting/interpreting section 100, the map data of a corresponding area 
is retrieved from the map data base 101 by a map data retrieving section 
104, and converted into display data by a data format converting section 
114. Also, an attribute data retrieving section 105 retrieves 
three-dimensional attribute data having a correspondence relation with the 
retrieved map data from the attribute data base 102. An attribute data 
format converting section 107 converts the retrieved data into data having 
a list format. Also, the converting section 107 converts the retrieved 
attribute data into data which can be displayed two-dimensionally. A data 
format converting section 114 combines the map data prepared for display 
and attribute data, and a screen format generating section 109 generates 
display data which matches the screen of a display unit 110 such as a CRT 
which displays the display data on the screen. 
Next, description will be made of a method for retrieving attribute data 
having three-dimensional characteristics from the attribute data base 102 
and for making the attribute data to have a correspondence relation with 
each of display elements of a two-dimensionally displayed map by the 
converting section 107 in the map information system. First, figure and 
image data for making a two-dimensional display of figures or a map are 
stored in the map data base 101 in advance. For example, plane map data as 
observed from above, such as a map of the East and West area shown in FIG. 
2, is stored in the map data base. On the other hand, attributes relating 
to each owner in a vertical axis with attribute items such as number of 
floors, residence number, name of owner, address and other attributes of 
the owner in a horizontal axis are stored in the attribute data base 102 
in a relational format, as shown in a residence attribute list in FIG. 2, 
for example. A method of displaying attribute data of residents in a 
building having three-dimensional characteristics, having one-to-one 
correspondence relation with the attribute data to figure elements of the 
map data without any inconsistency, can be broadly classified into the 
following two types: 
1 A case where a format of detailed figure elements having a correspondence 
relation between a layout diagram for each resident within a building and 
attribute data such as a tenant residence diagram for an underground 
street, can be known in advance, and 
2 A case where figure elements are not known at all. 
In the case 1, it is generally almost impossible to understand a layout 
diagram for individual residents within a building and a state of tenant 
residence in the underground street. Therefore, in many cases, a detailed 
state cannot be obtained. Accordingly, in the present embodiment, 
description will be made of a method for displaying figure element which 
corresponds to attribute data as a virtual layout diagram for residents 
within a building, by using data obtained by checking the contents of an 
attribute data base, obtaining a maximum value of the number of residents 
for every floor in the building, and extracting a maximum of numbers of 
floors, based on the assumption of the above case 2. For example, as shown 
in FIG. 3, a virtual residence layout diagram of a nine-floor "ABC" 
apartment house is displayed on a lower window. In the window, numbers of 
floors are displayed vertically and maximum numbers of residents at 
different floors are displayed laterally to make correspondence between 
the vertical and horizontal axes. In the example of FIG. 3, names of 
residents together with residence numbers are displayed at corresponding 
positions of each layout diagram. 
An outline flow for displaying the virtual residence layout diagram as a 
graphic output in the display unit 110, in the case of 2 above, will be 
explained below. It is assumed that a format of resident attribute data 
having three-dimensional characteristics that are to be stored in the 
attribute data base 102 is managed in the relational format such that 
attribute items including resident ID, residence number, number of floors, 
resident name, telephone number, contract capacity, etc. are taken in the 
lateral direction and attributes for each resident are disposed for every 
item in the vertical direction, as shown in FIG. 4. 
A flow diagram of processing for preparing a virtual residence layout 
diagram by using the attribute data base 102, will be explained with 
reference to FIG. 5. First, in Step 501, a variable St Max representing a 
number of a highest floor of a building is initialized. In Step 502, 
values of floor numbers are sequentially checked for all the columns of 
floor number items of the attribute data base (for example, FIG. 4). In 
Step 503, the values of floor numbers which have been obtained 
sequentially are set as a variable St Temp. In Step 504, a determination 
is made on whether a value of the variable St Temp is larger than that of 
the variable St Max which has been stored already. If the value of the 
variable St Temp is larger than that of the variable St Temp, the value of 
the variable St Max is replaced by that of St Temp in Step 505. By 
repeating the above steps, a maximum value of floor numbers St Max for the 
building can be obtained. 
In Steps 506 and 507, the values of a counter Sb Max [I] from "1" to St Max 
are initialized to take values of zero, for checking a value of a maximum 
residence number for each floor of the building. In Steps 508, 509 and 
510, a maximum residence number for each floor of the building is checked 
by referring to the residence number column of the attribute data base 
102. In Step 508, the residence number column of the attribute data base 
is checked from the first to the St Max floors. In Step 509, residence 
numbers are checked repeatedly for the whole of any J-th floor. In Step 
510, the obtained residence number is set as a variable Ls Temp. In Step 
511, the variable Ls Temp is compared with a temporary maximum value of 
floor number SbMax [J]. If the variable Ls Temp is larger than the SbMax 
[J], the SbMax [J] is replaced by the variable Ls Temp in Step 512. By 
repeating the above series of Steps 508 to 512, a maximum number of 
residents on each floor is obtained. 
Last in Steps 513 and 514, a virtual development elevation diagram of the 
building as shown in FIG. 3 is obtained by referring to a value of the 
maximum number of residences SbMax [St Max] for each floor that has been 
obtained above. Various methods can be considered for preparing the 
development elevation diagram obtained in Steps 513 and 514. In this case, 
a method for disposing residences within the window by fixing the shape of 
a residence to a rectangle of constant dimensions is disclosed. The flow 
of the processing is shown in FIG. 6. In Step 601, the attribute data base 
102 is checked from 1 to a maximum number of floors St Max of the 
building, to obtain a maximum number of residences on each floor. In Step 
602, values of the residence number counters on each floor are each 
checked sequentially, to obtain a maximum value SbMax. In Step 603, an X 
direction size Wx and a Y direction size WY of an effective display area 
of the window for making a display of the residences is set. In Step 604, 
an X direction size DX=WX/SbM Max for a residence frame is obtained for 
displaying each residence within the building. In Step 605, a y direction 
size DY=WY/St max for a residence frame is obtained. In Steps 606 and 607, 
rectangles of St Max numbers in the vertical direction and Sb Max [J] 
numbers in a lateral direction, is prepared and drawn on the screen as 
shown in Step 608. Within each residence frame which has been drawn, 
various kinds of attribute data corresponding to the residence number are 
displayed as text data. 
As a method for displaying a residence layout diagram to be prepared 
virtually, other modified display methods can also be considered, such as 
a method for selectively rearranging only residences of the same floor and 
displaying these residences by virtually dividing the building laterally, 
or a method for selectively rearranging only residences of the same 
residence numbers and displaying these residences by dividing the building 
vertically. These alternative methods can be realized by applying a 
processing of extracting data of the same conditions to the processings 
shown in FIGS. 5 and 6, by looking at the residence number column and the 
floor number column of the attribute data base 102 shown in FIG. 4. Since 
the flow of the processings shown in FIGS. 5 and 6 can remain the same to 
achieve the above processings, these processings are not explained. 
Detailed description has been made about the method of displaying resident 
attribute data having three-dimensional characteristics by correlating 
these data to the virtually prepared residence layout diagram at a 
proportion of one to one. A method of displaying the above in other format 
can also be considered. According to the method shown in FIG. 3, the 
residence layout diagram prepared virtually has been displayed in a 
window. According to the method to be described below, however, a virtual 
layout diagram is displayed at first within the frame of the building to 
be retrieved within the same window, as shown in FIG. 7. A method for 
preparing the virtual layout diagram will be explained below. 
First, the content of the attribute data to be displayed is checked, to 
obtain a maximum floor number of a building St Max and a maximum residence 
number SbMax [j] or each floor based on the flow of the same processing as 
shown in FIG. 5. However, in the case of displaying this data, all the 
residence numbers within the building cannot be displayed at one time. 
Therefore, display of data is made after the user has designated, at the 
inputting/interpreting section 100 in FIG. 1, a condition for fixing only 
a certain floor of the building or for fixing a residence number, by 
dividing the building laterally or vertically. In this case, the residence 
layout diagram to be displayed has not been stored in the data base in 
advance. Therefore, it is necessary to process the data so that the data 
can be stored within the building to be displayed, if necessary. The flow 
of the processings is shown in FIG. 8, and the details of the processings 
will be explained below. 
In Step 801, a maximum rectangle which can be drawn within a closed figure 
of the building to be displayed is searched and set, and the width and the 
height of the rectangle are expressed as CX and CY respectively. Next, in 
Step 802, optimum sizes (the width DX and the height DY) of the frame of 
the residence to be displayed within the rectangle are obtained. One of 
the methods for this is as follows. A ratio of the width to the height of 
the residence frame is decided in advance. By using this ratio, the size 
of a rectangle for a residence layout is decided such that there is 
minimum space between each square for showing each residence when a 
maximum number of residences SbMMax are arranged for each floor within the 
rectangle for showing the closed figure of the whole building. By using 
the width DX and the height DY of the rectangle for the residence frame 
obtained by the above procedure, the following processings are repeated 
until the user finishes the display assignment (Step 803). In Step 804, a 
floor number Sb of the floor concerned for assigning the portion for 
displaying the residence frame is set. All the residence attribute data 
belonging to the Sb floor are searched from the attribute data base 102, 
and the record number obtained is set as NSb (Step 805). In order to 
display the obtained residence attribute data together with the residence 
layout frame rectangle, the layout display already being displayed within 
the building is deleted first (Step 806). Then, the following display 
processing is repeated for the number of retrieved records NSb. In Step 
808, the X coordinate CTX at the reference position down left in the 
residence frame rectangle is obtained by an expression CTX=CTX+DX. Next, 
whether the value of CTX is larger than the width of the inscribed 
rectangle within the building or not is checked (Step 809). If CTX is 
larger than CX, the display of the residence frame exceeds the width of 
the inscribed rectangle. Therefore, the size of CTX is adjusted by the 
width of the inscribed rectangle based on the expression CTX=CTX-CX (Step 
810). For the size of the residence frame in the Y direction, the size is 
exploded in the downward direction based on the expression CTY=CTY+DY 
(Step 811). On the other hand, when CTX is equal to or smaller than CX, 
the display of the residence frame is accommodated within the width of the 
inscribed rectangle. Therefore, the width of the residence frame is simply 
increased based on the expression CTX=CTX+DX (Step 812). Then, with each 
(CTX, CTY) as reference coordinates down left, the rectangle of the height 
DY and the width DX for showing the layout of the residence frame is drawn 
inside the inscribed rectangle (Step 813). Corresponding attribute values 
are retrieved and formatted inside the rectangle for showing the layout of 
the displayed residence frame, and then the data is outputted (Step 814). 
According to the present invention, attribute data having three-dimensional 
characteristics can be easily made to correspond to a two-dimensionally 
displayed map at a proportion of one to one without any duplication with 
the object of the map. Therefore, the operation at the time of a retrieval 
or editing is made clear, with a substantial improvement in the 
man-machine characteristics. 
Next, another map information system of the present invention will be 
explained below with reference to the accompanying drawings. 
FIG. 9 is a block diagram showing a functional configuration of the map 
information system. The system includes broadly four sections, that is, an 
operation section, a processing section, a data base section and a display 
section. The operation section includes a command input and interpretation 
section 100 for receiving a command from an operator shown at the left of 
FIG. 9 and interpreting the content of the command. The display section 
includes a screen format generating section 109 and a display unit 110 
such as a CRT as shown at the right of FIG. 9. The data base section 
includes a map data base 101 for storing map data including data of 
various elements corresponding to figures and texts displayed on the 
display screen, an attribute data base 102 for storing attribute data or 
data associated with map data having three-dimensional characteristics and 
indicating an attribute of each house, e.g., {number of floors, a 
residential number, owner of the house, telephone number, etc.}, a layout 
data base 103 for storing a diagram of the layout, such as a shop layout 
diagram or a tenant residence diagram, which exists separate from the map 
data, and an object base 112 for storing, in an object format, information 
indicating a relation between objects and between media such as the map 
data, the drawing (layout) data and the attribute data. Each data base is 
stored in a different file. 
The processing section includes an object retrieving and executing section 
111, a map data retrieving section 104, an attribute data retrieving 
section 105, a layout data retrieving section 106, an attribute data 
format converting section 107, a layout data format converting section 
108, a data format converting section 114, a height table 113, and a 
three-dimensional perspective coordinates conversion processing section 
115. The retrieving and executing section 111 retrieves and executes 
entity objects from a plurality of objects, in accordance with the result 
of the interpretation by the section 100. The retrieving sections 104, 105 
and 106 retrieve map data, attribute data and layout data in accordance 
with the execution of a map data entity object, an attribute data entity 
object, and a layout data entity object, respectively. The converting 
sections 107 and 108 match the display formats of the attribute data and 
the layout data to that of map data, respectively. For example, the 
display position of the attribute data is matched to that of the map data. 
The converting section 114 converts the formats of the map data and 
attribute data. For example, in the case of the three-dimensional display, 
height data is obtained by referring to the table 113, and the map data, 
the layout data and the attribute data are converted to three-dimensional 
data. When a bird's-eye display has been instructed, the section 114 
initiates the processing section 115 so as to convert the coordinate 
system of the three-dimensional data from a world coordinate system to a 
viewpoint coordinate system. The height table 113 stores height data per 
one floor which has been determined in advance in accordance with types of 
figure data as a display element of the map data. Accordingly, when the 
section 114 refers to the table 113 in accordance with the types of 
display element and the number of floors, the height of the display 
element can be obtained. 
Description will be made of an outline of a flow of a series of processings 
from data retrieval to a three-dimensional display which are to be carried 
out under the above-described structure when an operator has issued a 
request for making a three-dimensional bird's-eye display of a portion of 
a map. When an operator has issued the request for designating a range of 
the retrieval and for processing the retrieval or editing to the section 
100, the section 100 converts the request into a message for an object and 
supplies the message to the retrieving and executing section 111. 
When the message has been given to one among relational object groups which 
exist for each of various types of processings in the object base 112, a 
necessary number of messages are transferred to entity objects in 
accordance with a procedure in the relational object to which the message 
is given, so that each entity object initiates the retrieving section 104, 
105 or 106 so as to retrieve the content of the data base 101, 102 or 103. 
First, the retrieving section 104 retrieves map data of an area designated 
by the request from the map data base 101 and converts the map data into 
display data. The retrieving section 105 retrieves three-dimensional 
attribute data having a correspondence relation with the retrieved map 
data and layout data from the attribute data base 102, and the converting 
section 107 converts the data format of the retrieved attribute data into 
a data format which corresponds to the retrieved map data and layout data. 
The retrieving section 106 retrieves, from the layout data base 103, the 
layout data corresponding to the figure elements of the map data which has 
been retrieved by the retrieving section 104. The layout data converting 
section 108 converts the layout data so that it is completely superposed 
on the corresponding figure element. The section 114 refers to the table 
113 in accordance with the display format of data, and causes the section 
112 to convert the data format. The generating section 109 converts the 
formats of the map data, the layout data and the attribute data as the 
display data from the section 114 into formats that fit for the screen, 
and displays the data on the display unit 110 such as a CRT. As described 
above, the data bases 101, 102, 103 and 112 of the map information system 
are divided into four data files. The map data and attribute data that 
have been indirectly extracted by being related to the relational object 
stored in the object base 112 are displayed in accordance with the 
processing procedures exclusively used for the media, respectively. 
Separate from the above series of processings, in order to retrieve the map 
data and the attribute data, it is necessary to convert each of the 
contents stored in the data bases 101, 102, and 103 into an object and to 
transfer the converted object to the object base 112 to store it therein. 
The contents of the data bases 101, 102 and 103 necessary for a 
three-dimensional display are retrieved and extracted by the retrieving 
sections 104, 105 and 106, respectively, and are converted into objects by 
the section 111 such that the objects are stored in the object base 112. 
This series of processing is carried out whenever required and is 
processed at a timing different from that of the processing from the 
issuance of the request for retrieval from an operator to the 
three-dimensional bird's-eye display. 
FIG. 10 shows the contents of the four data bases 101, 102, 103 and 112 
relating to the map displayed on the display unit 110. The map data base 
101 stores figure data of roads and house frames and text data for names 
of places, which are necessary for displaying a normal two-dimensional 
map. Further, residence layout data 201, 202, 203 and 204 for showing the 
residence layout of each floor are stored in the layout data base 102. The 
layout data base stores mainly a border figure of residence frames of each 
floor, and does not necessarily store residence numbers and names of 
residence owners. Residence numbers and names of residence owners may be 
retrieved from the attribute data base 103 and displayed so as to be 
accommodated within each residence frame by processing or modifying the 
format, as shown in FIG. 10. The object base 112 stores entity objects, 
each of which is is made to correspond to a content of each of the data 
bases 101, 102 and 103, and relation objects which describe relations 
between the entity objects. 
Under the above-described system configurations and process flows, the data 
structure of each data base will be explained in sequence. 
The map data is divided into a figure portion and a text portion as shown 
in FIGS. 11A and 11B respectively. Each data portion is of a sequential 
format of a variable length. The figure portion in FIG. 11A is composed of 
a figure table header and records. A file size of the whole figure portion 
and the number of records are stored in the file table header, and in each 
record are stored data indicative of the number N.sub.1 of constituent 
points of coordinates that constitute a figure, a type of line KL1 for 
designating a type of the figure, and a color in drawing the figure and so 
on; information SI, and EI indicative of a starting point and an ending 
point of the figure necessary for knowing a state of processing in 
editing; and X coordinates and Y coordinates (X.sub.1, Y.sub.1, . . . 
X.sub.M, Y.sub.M, . . . XN.sub.1, YN.sub.1) for the number of the 
constituent point. 
The text portion in FIG. 11B is composed of a text table header and 
records. A file size of the whole text portion and the number of records 
are stored in the file table header, similar to the figure portion, and in 
each record are stored data indicative of the number M.sub.1 of 
constituent letters which constitute a text, a type of text KT1 for 
determining a font of the text, such as a classic Chinese letter font or a 
Gothic letter font, a box width W.sub.1 and a box height H.sub.1 for 
giving a width of a circumscribed rectangle relating to the size of each 
text letter, a slope angle V.sub.1 of each text letter within the 
circumscribed rectangle, a rotation angle R.sub.1 for rotatingly 
displaying a plurality of letters as a text, a flag F.sub.1 for 
controlling the direction vertically or laterally displaying the text, X 
coordinates X.sub.1 and Y coordinates Y.sub.1 of a reference point 
indicative of a reference position for displaying each text, and text code 
data (TC.sub.1, TC.sub.2, . . . , TCM.sub.1 ) for each text. 
The data structure of the third layout data base 103 has two types of, 
including a figure portion and a text portion. The data structure may be 
exactly the same as the data format of the map data base 101 shown in 
FIGS. 11A and 11B. However, the reference coordinates of the figure may be 
independent of the reference coordinates of the map data base 101, and the 
coordinate conversion parameters such as expansion, compression and 
movement for completely superposing the layout data on the map data are 
stored in the relational object within the object base 112. 
The attribute data base 102 is structured of resident attribute data having 
three-dimensional characteristics, and this is a relational data base as 
shown in the reference 3 which can store and manage various types of 
attribute values in a resident unit. As shown in FIG. 12, items {a 
resident identifier, a residence number, a number of floors, a name of the 
owner, etc.} are set in the lateral direction of the attribute data base, 
and attribute values of each resident are stored and managed in the 
vertical direction thereof. By the above arrangement, conditional 
retrieval subject to each item of attributes, which is a feature of the 
relational data base, becomes possible. For example, a conditional 
retrieval for retrieving names of residents living in the second floor of 
a house with 3DK (three living rooms and a dining kitchen room) becomes 
possible by using a structured query language (SQL) which is a standard 
language for a retrieval procedure shown in the reference 3. 
Before describing the structure of the object base 112, definition and 
characteristics of a relational object in the present embodiment will be 
made clear. In general, an object means a capsuled unit of defined data 
and a procedure for directly processing the data, as shown in the 
reference 4. Usually, the relational object refers to a unit which can be 
described in an object-oriented language as shown in the reference 4. The 
structure of objects includes classes, in each of which a common concept 
can be defined hierarchically and instances, in each of which the 
definition of each class is expressed in an inherent value. A class can 
generate inherent instances when necessary, and a group of instances 
generated by the same class can hierarchically inherit and share 
definitions of variables and procedures of the class. For example, an 
object can be described in the following format by using an 
object-oriented language, objective-C, which is shown in the reference 4: 
______________________________________ 
object = name of a class: super-class name (message: 
group 1, group 2, . . . ) 
{declaration of an instance variable} 
+ a single term selector {a factory method definition} 
- a single term selector {an instance method definition} 
+ selector 1: a temporal argument 1, a selector 2: 
a temporal argument 2, . . . {a definition of a class 
method} 
- a selector 2: a temporal argument 1, a selector 2: a 
temporal argument 2, . . . {a definition of an instance 
method}. 
______________________________________ 
In the above description, the factory method is a definition of a detailed 
procedure for generating an instance by each class. In the case of 
Objective-C, the procedure is described in the C language. A selector has 
identifiers which are necessary for receiving a message to make a request 
to each method, and a single-term selector means a selector having only 
one identifier. 
From the viewpoint of describing multimedia such as figures and images, 
objects can be classified into entity objects and relational objects, as 
shown in the reference 5. An entity object is a description of a set, 
including a definition of data and a processing procedure, for the media 
data, the media data being a single kind of media itself such as a figure 
or an image. On the other hand, a relational object is for establishing a 
meaningful relation among a plurality of media including resident 
attributes and figures of house frames or among a plurality of other 
relational objects and is a description of a combination of pointer 
information to entity objects and procedures for mainly issuing a message 
to each entity object. 
First, the structure of an entity object will be explained based on an 
example of a description of the entity object from the viewpoint of making 
a three-dimensional bird's-eye display of a house frame designated on a 
housing map. 
FIG. 14 shows a structure of a figure entity object PHL001 indicative of a 
house frame and a structure of a text entity object PHT001 in 
correspondence with map data. A figure record and a text record, which 
correspond to a house frame of each resident, are described in a table 
file LRT001 which structures the figure portion of the map data and in a 
table file TRT001 which structures the text portion shown in FIGS. 11A and 
11B, respectively. Each of the figure and text records can be 
independently accessed in accordance with address information ADL001, 
ADL002, . . . , ADT001, ADT002, . . . for indicating a position of the 
record in the table file of variable length and the number of constituent 
points or texts in the record. Of the figure entity object PHL001 of the 
house frame, in the Definitions are defined a file pointer Files=LRT001, a 
record pointer Address=ADL003 and entity variables X[N] and Y[N], and in 
the Methods is described a procedure LineDraw (N, X, Y) for displaying a 
figure of the house frame. On the other hand, of the text entity object 
PHT001 of the house frame, in the Definitions are defined a file pointer 
Files=TRT001, a record pointer Address=ADT002 and an entity variable 
SL[M], and in the Methods is described a procedure TextDraw (N, SL) for 
displaying a text string for the house frame. Therefore, by giving only a 
message DRAW for a display request to these objects, the procedures 
LineDraw (N, W, Y) and TextDraw (N, SL) in the Methods of the objects are 
initiated to display the house frame and the text string on the display 
unit 110. 
FIG. 15 is a diagram showing an example of a three-dimensional bird's eye 
display of an apartment house AB of the map data shown in FIG. 14. In 
response to a command for a bird's eye display in a map data entity 
object, reference height data is obtained by referring to the height table 
113 in accordance with the floor data of the apartment AB of the attribute 
data, and the reference height data is multiplied by the number of floors 
so as to obtain the height of the apartment AB. Next, the 
three-dimensional map data and attribute data are sent to the section 115 
which carries out a conversion processing. The result of the processing is 
displayed on the display unit 110 through the section 109. The display 
position of the attribute data, e.g., the display position of the text 
data "AB apartment" is altered by the section 107 from the position shown 
in FIG. 14 to the position shown in FIG. 15 to match the three-dimensional 
display of the map data. 
FIG. 17 shows a structure of each of various layout entity objects {PHS101, 
PHS102, . . . , PHS201, PHS202, . . . } which are indicative of layouts of 
respective floors within an apartment. Each of the objects has a 
one-to-one correspondence relation with one of the layout files {LRST01, 
LRST02, . . . }. These layout files have the same format as the figure 
section of the map data shown in FIG. 11A and each layout data is 
described as a figure record in one-to-one correspondence relation with 
one resident. Also, the layout data can be accessed independently in a 
unit of figure record by use of the number of constituent points and 
address information {ADSL101, . . . , ADSL201, . . .,} pointing to the 
position of the figure record in the file table of variable length. 
FIG. 13 shows a structure of an attribute entity object AT001 of a 
resident. As shown in FIG. 12, the attribute data base is of a relational 
structure having attribute items in the lateral direction and individual 
personal data in the vertical direction, and can be accessed independently 
for each column. The object AT001 includes pointer information such as a 
pointer for an attribute data file, Files=RDB001, and a pointer Keys=KEX 
as a pointer indicative of the position of an objective record in the file 
in the Definitions and a retrieving procedure in a record unit subject to 
a retrieval language SQL for the relational data base in the Methods. 
Accordingly, in order to retrieve attribute data of one record for a 
resident having KEX as a resident ID, by only sending of a retrieval 
request message GET having a parameter of KEX to the object AT001, the 
retrieving procedure in the object AT001 is initiated, thereby to obtain 
attribute data. 
The above describes the structure of an entity object closely related to 
each media. A relational object is also stored in the object base 112. As 
described already, the relational object is for establishing a meaningful 
relation among a plurality of media for purpose of three-dimensionally 
identifying residents within an apartment. The relational object describes 
a combination of pointer information for relating necessary ones among the 
entity objects described above and a procedure mainly for transferring a 
message to each entity object. In order to simplify the internal 
structures of relational objects of a hierarchical structure, there are 
some relational objects which intermediately group entity objects for 
medias of the same kind. 
FIG. 16 shows a relation object PH001 for relating the figure entity object 
PHL001 and the text entity object PHT001 of the house frame shown in FIG. 
14. When a message DRAW for requesting a display is given to the object 
PH001, the messages given to the Methods of object PH001 are transferred 
to the objects PHL001 and PHT001, which are defined in the Definitions of 
the object PH001, by a message transfer function between objects, thereby 
to initiate the procedure LineDraw of the object PHL001 for displaying a 
house frame and the procedure TextDraw of the object PHT001 for displaying 
a house name. As a result of initiating the object PH001, the house frame 
and house name can be displayed. Thus, the structure of the relational 
object PH001 can be simplified. As shown in FIG. 18, a group of entity 
objects (PHS101, PHS102, . . . ) for a layout of houses or rooms within an 
apartment and a group of attribute entity objects of individual persons 
(AT001, AT002, . . . ) are related to generate a group of relational 
objects (PHA101, PHA102, . . . ). Further, the objects associated with the 
same floor are grouped to generate a relational object LPH001. By this, 
the structure of the relational object LPH001 can be further simplified. 
Last, as shown in FIG. 19, when a relational object H0001 for summarizing 
media meaningful for the apartment is generated, the object H0001 relates 
the groups of entity objects (PHS101, PHS102, . . . ), (AT001, AT002, . . 
. ) and (PHL001, PHT001, . . . ) corresponding to each media described 
above, to the groups of relational objects (PHA101, PHA102, . . . ), 
(LPH001, LPH002, . . . ) and (PH001, PH002, . . . ) which are the result 
of having grouped the entity objects at an intermediate stage. Further, 
the procedure portion thereof describes a transfer procedure for 
transferring a message for each entity object. Thus, in order to display 
map data of the apartment, the message DRAW is given to the object H0001 
with the selectors LineDraw and TextDraw. 
In order to display data of room layout of individual persons, the message 
DRAW is given, together with the selector Layout Draw, to the object 
H0001. Particularly, a procedure for adjusting parameters such as display 
positions and multiplication factors becomes necessary for making a 
display of a complete superposition of room layout on the result of 
displaying the group of houses on a map. These parameters can be defined 
by filling in the variable definition portion and the procedure portion of 
the relational object H0001 and LPH001, thus requiring no separate 
arrangement. 
Next, description will be made of the method for making an effective 
display of the map data in one-to-one correspondence relation without any 
inconsistency by using map data objects, layout data objects and attribute 
data objects explained above. First, consider the case where the map data 
is displayed two-dimensionally on the display unit 110 in the same method 
as the conventional map displaying method, as shown in FIG. 20A. According 
to this display, each of many residents in an AB apartment in FIG. 20A 
corresponds to one of the building frames of the AB apartment, and it is 
impossible to investigate details of individual residents such as each 
resident name or retrieve various attributes associated with each 
resident. To avoid this problem, the operator designates a floor number to 
be retrieved, so that layout data of the residences belonging to this 
floor are displayed in the form to completely superpose on the building 
frame concerned. With this arrangement, attribute data and residence 
positions having one-to-one correspondence relation can be identified. 
Examples of this display are shown in FIGS. 20B and 20C. In FIG. 20A, the 
operator designates a periphery of the AB apartment to be retrieved with a 
pointing device such as a mouse. Then, the operator designates a floor 
number of the AB apartment, so that the layout data of the designated 
floor are superposingly displayed on the AB apartment frame. FIG. 20B 
shows the state that the layout data of the second floor are displayed, 
and FIG. 20C shows the state that the layout data of the underground 
portion are displayed. When the operator designates individual residence 
frames of the layout data of each floor, the attribute data relating to 
these residents can be retrieved with a complete one-to-one correspondence 
relation. What is important in this display method is as follows. Unlike 
the display shown in FIGS. 26 and 27 where the layout data for each floor 
are displayed in an independent window different from that for the 
building, the layout data are completely corresponded to the building and 
that even if the size of display or angle is changed from the original one 
due to a change of retrieving condition, the superposition display can 
completely follow this change. 
The flow of processing for realizing the display method of attribute data 
shown in FIGS. 20B and 20C will be explained below with reference to FIG. 
21. First, in step 1201, the figure portion and the text portion of map 
data are taken from the map data stored in the map data base 101 in the 
format as shown in FIGS. 11A and 11B, and these data are displayed as a 
two-dimensional map on the screen of the display unit 110. As an example 
of this display, shapes of buildings such as a church and a police station 
and roads together with their names are displayed. Accordingly, in the 
case of the two-dimensional display, only the name of a building and 
representative's name are displayed for an AB apartment house. Detailed 
layout within the building is not displayed at this stage. In step 1202, a 
building for which three dimensional attribute data are to be retrieved is 
designated on the screen of the display unit 110. Usually, the operator 
designates the building to be retrieved with a pointing device such as a 
mouse. A detailed processing for this designation is as follows. Assume 
the position coordinates to be designated on the screen of the display 
unit 110 by the pointing device is expressed as MP (MPX, MPY). The 
distances between from the MP point to the figure portion coordinates {X1, 
Y1, ---, XM, YM, ---, XN1, YN1} in FIG. 11A and the text portion reference 
coordinates (X1, Y1) in FIG. 11B are compared with each other so that the 
shortest instance can be found, and then a building concerned with the 
shortest distance is displayed in a flickering color on the screen. Thus, 
the designation is achieved. In Step 1203, the residence layout data and 
the resident attribute data which relate to the building designated in the 
preceding step are retrieved and displayed. As conditions for the 
retrieval of the layout data, the attribute data are used as a key for 
relating the layout data to the designated floor number to display the 
layout of the building and the figure number added to the building. For 
displaying the residence layout, a display request message DRAW with a 
parameter of the designated floor number and a selector Layout Draw: may 
be applied to an apartment house relational object H0001 shown in FIG. 19. 
Then, by the message transfer function between objects, the message is 
transferred to entity objects PHS** having the procedure of Layout Draw, 
and this message is executed by the entity objects. For retrieving the 
attribute data similar to the retrieval and display of the layout data, a 
retrieval request message GET with a residence ID parameter and a selector 
getRecords: is applied to the apartment relational object H0001. Then, by 
the message transfer function between objects, the data base retrieving 
procedure, getRecords, written in SQL is initiated, and target attribute 
data is obtained. A Step 1204 means to repeat a series of steps from Step 
1205 to Step 1211 by the number of floors within the building. By the 
operation using a mouse or keys designating a position on the screen of 
the display unit 110 by the operator, a layout position within a floor of 
the building can be designated as shown in Step 1205, and an ending 
condition for ending the series of operations can be given. In Step 1206, 
only the data for the designated floor are extracted from the layout data 
and the attribute data relating to the building which have already been 
obtained by designating the building on the display screen 110 in Step 
1203. The format of the layout data of the designated floor displayed at 
this stage is the same as the format of the map data as shown in FIGS. 11A 
and 11B. As explained above, the coordinate system is independent and the 
size is not standardized. Therefore, in order to completely match the 
layout data with the map data, the coordinate origin, the coordinate 
rotation and the coordinate expansion/contraction are converted (Step 
1207). In order to display the layout data so as to completely superpose 
it on the map already displayed, an affine transformation as shown in the 
above reference 2 is carried out. For the parameters for carrying out the 
affine transformation, it is necessary to determine a deviation from the 
coordinate origin (DX, DY), an angle of the coordinate rotation (8) and a 
contraction factor ML*. However, in general, there is degree of freedom in 
the registration of a layout figure. Therefore, in the present embodiment, 
both the layout and the map are based on the matching of a circumscribed 
rectangle. The matching of the reference coordinates is determined based 
on the left lower point of the long side of the circumscribed rectangle 
viewed horizontally, an angle formed by long sides for a rotation angle, 
and a ratio of the size of the long side to the size of the short side 
between the circumscribed rectangle for a contraction factor. Therefore, a 
value of the factor ML defined in the apartment relational object H0001 
and an offset position (DX101, DY101) defined in a relational object 
LPH001 for grouping the layout in a floor unit are used. A detailed method 
of transformation is as follows. As shown in FIG. 22, the coordinates of a 
point P (X', Y', ) defined by a layout coordinate system {X'-Y'] having an 
angle .theta. and deviations (DX, DY) from an origin of the map coordinate 
system [X-Y] is transformed to a point P' (X, Y) by the following 
transformation expressions: 
EQU X=X'cos.theta.-Y'sin.theta.+DX 
EQU Y=Y'sin.theta.+Y'cos.theta.+DY 
The point P' (X, Y) is transformed to a point P" (X, Y) based on the 
following transformation expressions, by considering a contraction factor 
from the correspondence between the residence and the layout drawings: 
EQU X=(X'cos.theta.-Y'sin.theta.+DX)/ML 
EQU Y=(Y'sin.theta.+Y'cos.theta.+DY)ML 
The displayed layout data having a complete matching with the corresponding 
building on the map is only a layout frame of each residence. Since the 
attribute data relating to the designated building have already been 
extracted from the attribute data base 102, only the attribute data of the 
floor corresponding to this layout data are extracted in Step 1208. In 
Step 1209, Steps 1201 and 1211 are repeated. In Step 1210, attribute data 
having a correspondence relation with each of houses defined by the 
residence frames on each floor are extracted, and only specific items such 
as a residence number, a name of the owner, etc. are extracted from these 
data. In Step 1210, the size of the attribute data having a one-to-one 
correspondence relation with the residence frame is converted to be 
accommodated within the residence frame, and the result is displayed. The 
conversion of the size of the attribute data to be accommodated within the 
residence frame is performed in accordance with the size of the 
circumscribed rectangle and the size of the residence frame, so that the 
circumscribed rectangle of the text data for the residence number row and 
the names of owners shown laterally can be determined to be accommodated 
within the residence frame. 
Description has been made about a method for displaying the layout data to 
completely superpose this data on the result of a two-dimensional map 
display in a floor unit. However, it is further possible to retrieve 
two-dimensional figure data representing the outer figure of a residence 
in a relational object HO** level of the apartment. It is also possible to 
retrieve residence attributes. By checking the attribute data, information 
relating to a maximum floor of the apartment can be obtained. When a 
height per floor of the building has been assumed, an absolute height of 
the building can be obtained. Accordingly, the apartment can be handled to 
have a three-dimensional data structure for an internal processing, so 
that a three-dimensional bird's-eye map display as shown in FIG. 15 can be 
obtained. The three-dimensional display algorithm is used to carry out a 
perspective conversion processing to obtain a bird's-eye display, as shown 
in the above reference 2. 
FIG. 24 is a flow chart (in a PAD format) for explaining the 
above-described three-dimensional display procedure. Each process will be 
explained in the order of the steps of FIG. 24. In step 1801, the whole of 
map data to be processed is read out from the data base 101 by the section 
104, and is two-dimensionally displayed in a window Win1 on the display 
unit 110 through the sections 114 and 109. This data is the map data 
itself stored in the map data base 101. In step 1802, an area to be 
three-dimensionally displayed out of the displayed map data in the window 
Win1 is designated. The area is designated by the operator through a 
pointing device such as a mouse operated on the window Win1, and a result 
of the designation is supplied from the section 100 to the section 111. In 
step 1803, determination is made whether each polygon vector is included 
in the designated area based on the figure data of house frames, etc. of 
figure entity objects stored in the object base 112. Based on the result 
of the decision, figure entity objects and text entity objects are 
extracted from the object base 112. For the attributes of the types of 
buildings and numbers of floors, attribute objects related to the 
extracted entity objects are referred to by the section 105 and are 
supplied to the section 114. The section 114 obtains a maximum value of 
the attribute of the number of floors related to the same type of 
building. In step 1804, the section 114 refers to the height table 113 and 
obtains height values of the buildings from the table 113, in which the 
height data per one floor are stored in advance in accordance with the 
type of the building. In order to obtain absolute heights of the buildings 
for the three-dimensional display, maximum numbers of floors of the 
buildings and the height values obtained up to the step 1803 are 
respectively multiplied to artificially estimate the absolute heights of 
the buildings. As described above, more accurately estimated values of the 
absolute heights can be obtained if average height per one floor to be 
stored in advance is set for a type of building such as a warehouse, an 
office building, etc. In step 1805, the section 114 converts a data 
structure of each display element included within the designated area. The 
map data to be extracted in the above steps are in the form of 
two-dimensional entity object as shown in FIG. 14. In the subsequent 
steps, this data is converted into the format of a three-dimensional 
entity object as shown in FIG. 15. In the present embodiment, 
three-dimensional objects of the format of FIG. 15 are prepared by the 
number of objects extracted, and the corresponding portions are copied 
directly. The estimated value of the absolute height of each building 
obtained in the preceding steps is used as a substitution for Z 
coordinates. On the window Win2 for carrying out the three-dimensional 
display, elements of the map data for the three-dimensional display are 
processed perspectively to obtain a bird's-eye three-dimensional 
coordinate system. In step 1806, parameters which are necessary for the 
conversion processing are set by the section 100. Details of the 
three-dimensional perspective conversion are explained with reference to a 
model having three coordinate systems as shown in FIG. 23. 
In FIG. 23, a group of three-dimensional figures to be perspectively 
converted is described as WC:[XW-YW-ZW] in a world coordinate system. 
These coordinates are to be converted on a viewpoint coordinate system 
Vc:[XV-YV-ZV]. As an assumption of FIG. 23, a viewpoint position on the 
viewpoint coordinate system Vc is at a position of (OVX, OVY, OVZ) in the 
world coordinate system Wc and a line-of-sight vector for looking at the 
three-dimensional figure group in the direction cosine (HX, HY, HZ) from 
this viewpoint is assumed. Further, the line-of-sight vector intersects at 
an angle of degrees with a [YV-ZV] plane in the viewpoint coordinate 
system Vc, and the line-of-sight vector intersects at an angle of .beta. 
degrees with the [YV-ZV] plane. In other words, the direction cosine and 
sine of .alpha. and .beta. have the following relation; 
##EQU1## 
In this case, in order to carry out the perspective conversion, the 
following four conversion matrices are obtained and the conversion 
processings are applied sequentially. 
(1) Carry out a parallel displacing conversion TD to match the viewpoint 
position with the origin of the viewpoint coordinate system VC. 
(2) Carry out a coordinate axis rotating conversion RX for rotating around 
the XV axis by .alpha. degrees so that the viewpoint vector is included in 
the [XV-ZV] plane of the viewpoint coordinate system VC. 
(3) Carry out a coordinate axis rotation conversion RY for rotating around 
the YV axis by .beta. degrees so that the ZV axis becomes parallel with 
the line-of-sight vector. 
(4) Carry out a coordinate axis rotating conversion for converting the ZV 
axis in an opposite direction. 
The content of the conversion matrix to be used for each of TD, RX, RY and 
RZ is as follows 
##EQU2## 
In order to display the layout data on the map of the three-dimensional 
bird's-eye display by making an identifiable correspondence between these 
data and the map, a method of display as shown in FIG. 25 can be 
considered, where the user designates the building and the floor number of 
the building, and the layout data are displayed to make correspondence on 
the building frame for which the designated floor has been virtually 
extracted. To achieve this display, a message GET for retrieving a floor 
number from the attribute data base is sent to an object PHA** to which 
the layout data and the attribute data are related, as described above, 
and the floor number in which the layout data exist is obtained. An 
absolute height of the building in which the layout data exist is obtained 
from a virtual value of the height per one floor. By carrying out a 
three-dimensional perspective conversion in the same manner as that for 
the map described above, the layout data can be correspondingly displayed 
on the bird's-eye display of the apartment. In the case of FIG. 25, a 
display of the layout data is made by deviating the coordinate axis to a 
lateral direction (for example, the XW axis direction) from the 
corresponding position of the apartment, so that the layout display is not 
interfered with by the residence frame for indicating the apartment. A 
display of the layout data by deviating the coordinate axis to a vertical 
direction (for example, the YW axis direction) can also be considered. The 
flow of the processings for making a display of the layout data on the 
three-dimensional bird's-eye display of the map is almost the same as that 
shown in FIG. 21, except for Steps 1207 and 1208, and the layout data is 
displayed by completely superposing the data on the building frame in FIG. 
21. In other words, in the case of a three-dimensional bird's-eye display, 
the building frame to be prepared virtually is in the perspective 
coordinate system, so that a perspective conversion processing needs to be 
applied to the simple coordinate conversion processing which is based on a 
rotation and a size conversion, to completely superpose the layout data on 
a rectangle which is taken out virtually in a floor unit. Further, the 
processing for taking out a virtual crossing surface by floor of the 
building frame can be achieved by fixing the Z axis in each floor height 
to prepare a two-dimensional figure of (x, y) and by drawing again the 
reference position of the figure around the coordinate position indicated 
by the user with a mouse or the like. 
When the layout data is for a wide region such as a shop layout diagram of 
the underground street as shown in FIGS. 26A, 26B and 26C, it is not 
possible to have a complete superposing relation between the layout data 
and only a certain building. In this case, it is necessary to have a 
superposing relation over the whole region of the displayed screen, and it 
is meaningless to replace a superposing portion as shown in FIGS. 20A to 
20C. It is also inconvenient to make a three-dimensional bird's-eye 
display of the layout data for each floor in the same manner as shown in 
FIG. 31 because the display of the map on the ground may interfere with 
the display of the layout. To avoid this problem, as shown in FIG. 27, the 
map data of the ground portion for the whole region is displayed on the 
screen of the display unit 110. When it is desired to look at the state of 
the underground in a three-dimensional display, the area of the 
corresponding portion is designated with a pointing device such as a mouse 
or the like, and layout data which correspond to the position and the area 
are extracted and displayed superposingly, so that the layout of only the 
required portion can be displayed. The attribute data having 
three-dimensional characteristics are retrieved from the attribute data 
base 102 and are displayed at the corresponding position of the layout 
data which have been obtained above. FIG. 27 shows the map of the ground 
surface portion on the whole screen and also shows the areas showing two 
underground states of an underground B1 portion and an underground B2 
portion. In the case of the display method shown in FIG. 27, the state of 
a certain underground floor can be displayed as if a superposed sheet is 
removed, only when a position and an area to be retrieved 
three-dimensionally have been designated. Therefore, this is slightly 
different from the concept of a simple window which has been practically 
used in the work station or the like. In other words, in the case of the 
window, the content being displayed can be disposed at any position within 
the screen without changing the content of the screen, independent of the 
display position of the window. However, in the case of the present 
embodiment, the bottom state of the position corresponding to the 
designated area is displayed in synchronism with the move of the layout of 
the designated area. The display as shown in FIG. 27 can be made in the 
same method as explained in the flow of the processing above, except for a 
partial different. In other words, in the retrieving section 106, the 
layout data is expanded so as to completely superpose on the map 
displayed, and only the designated area is extracted from the display unit 
110. This processing, the so-called "clipping processing", may be in the 
same method as shown in the reference 2, for example. This clipping 
processing can be achieved by the basic processing in the general computer 
graphics. In other words, as shown in FIG. 28, a mask for clipping in a 
floor unit is provided and an AND figure to the layout data in each floor 
and the corresponding mask for clipping is prepared, and the AND figure is 
transferred to within the square which is equivalent to the clipping mask 
on the map of the ground surface and then is displayed. For example, in 
the case of preparing an AND figure between the layout data of the 
underground B1 and ABCD mask data shown in FIG. 28, the inside of the 
square ABCD is set at a value of 1 and the outside shown by shaded lines 
is set at a value of zero and a logical product calculation is carried 
out. Then, the underground B1 figure only inside the square ABCD is 
obtained. A square of a background color having the same dimensions and 
the same position as those of the inside of the mask data is displayed on 
the map of the ground surface, and the logical product layout data of the 
underground B1 are displayed on this square, thus preparing the AND 
figure. Further, when the above processing are repeated for the 
underground B2, the layout corresponding to the underground B2 can be 
superposingly displayed on the underground B1 as shown in FIG. 27. 
Three methods have been shown above for the display of layout data. In the 
above description, vector data given by the coordinate column as the 
figure portion in FIG. 11A have been assumed and the text data given by 
the character code string as the text portion in FIG. 11B have been 
assumed in the map data base 101 and the layout data base 103 
respectively. However, in general, individual private information is 
included, in many cases, in the layout information within a building. 
Accordingly, the layout information exists in many cases, as simple image 
information having no vector or text as a public data base. Even in this 
case, the above-described method for superposingly displaying the layout 
data on the map basically remains unchanged. However, the object for 
carrying out coordinate conversion and affine transformation for 
completely superposing the layout data on the residence frame on the map 
changes merely from the coordinate and text data to the image data. Actual 
conversion processing changes merely from the coordinate point of (x, y) 
to a pixel unit of an image. Map information in a certain area may not be 
digitalized as is done in the center of the town. In this case, the map 
information is displayed as an image on the display unit 110 and building 
information is converted from a building image into vector data by the 
method as shown in the reference 4, to make it possible to make an 
individual access of the buildings. By using these data as a retrieval 
key, the layout information can be retrieved in exactly the same manner as 
the above-described method.