JP4113649B2 - 3D map creation method, recording medium recording 3D map creation program, and 3D map creation system - Google Patents

Description

【００２１】
この建物データは２次元電子地図に付随したものを用いたほうが、各種データ同士の整合性を取る意味合いからも３次元地図作成効率は高いが、状況によっては他のメディアからインポートすることも考えられる。
データとしては、建物毎の固有番号、地図中の座標値、住所、建物名、建物種別、階数、材質といった情報が列挙されており、検索・整理・保存が可能なようデータベース化されている。これらの情報が地図３次元化の作業に際しての基本情報となるのである。
【００２２】
続いて、図２に示す本発明の３次元地図作成方法の処理システムを概略説明する。３次元地図を作成するにあたりベースとして使用する２次元地図の建物情報が、階数情報を備えていない場合、もしくは備えていても全建物についてではない場合、本発明における階数情報補完ステップ２１を利用する。このステップにおいては前記建物情報に含まれている建物の材質情報Ｍ、主用途情報Ｕ、床面積（底面形状情報Ｂ）のうち少なくともいずれかの情報により２次元地図上の各建物の建物種別と材質とを推定し、該当地区における建物種別及び材質毎の階数統計情報（地区建物統計情報Ａ）により当該建物の階数を確率計算して決定する。
【００２３】
材質情報Ｍが得られなかった場合には、建物情報に含まれる建物の階数情報Ｆと、該当地区に存在する建物の階数や構造等を規定した建築基準法や災害地区指定などの地域情報とにより各建物の材質を推定する（材質情報補完ステップ２４とする）。 この時点で、各建物について、低層・中高層の事業所及び個人住宅といった建物種別、木造又は耐火材といった材質、そして階数が決定されていることになる。
【００２４】
建物の階数情報Ｆが最初から建物情報に含まれているか、もしくは上記の様に階数情報補完ステップ２１により階数が決定された後、建物の種別に応じて１フロア当たりの高さをフロア高可変ステップ２２において決定する。ここでは当該建物の種別毎に、地区建物統計情報Ａなどから予め得られた１フロアあたりの高さ情報を建物毎に反映させることとなる。
【００２５】
次に、２次元地図に示されている各建物毎の底面形状を底面形状情報Ｂから抽出し、既に求めた建物種別、材質、階数、１フロア当たりの高さといったデータと併せることでいよいよ建物の立体化が図られる。詳細は後述するが、基本としては底面と対向する上面（屋根部）を作成し、それらの接辺毎に側壁を作成する。
【００２６】
この際、建物の主用途Ｕ及び材質情報Ｍと、予め定めた主用途Ｕ及び材質Ｍ毎の建物形状情報（部品形状Ｐ）または建物外装情報（色・テクスチャ情報Ｃ）とに基いて、３次元化する各建物の形状または外装を可変可能である（形状変更ステップ２６及び外装変更ステップ２７）。形状変更とは主に屋根形状を指し、例えば和風木造建築であれば切妻、或いは寄棟といった屋根を選択するのである。また、外装変更とは、建物の材質に応じて、例えば木造なら木目のテクスチャを、耐火材ならコンクリート風のテクスチャを側壁に施すのである。
【００２７】
このように作成された建物の３次元データは立体形状情報Ｓとして保存蓄積され、３次元地図として他のデータと統合されることとなる。
【００２８】
なお、上記の各機構は各種情報を収めたデータベースとそれらと連結したコンピュータにより主に構成されるものである。
【００２９】
＝＝＝メインアルゴリズム＝＝＝
本発明の３次元地図作成方法を実施する主処理アルゴリズムを図３に示し、これにのっとった建物３次元化の手順を（１）〜（８）に示す。
【００３０】
（１）立体化する地区を指定し、その地区内全ての建物について、立体化の処理を行う。係る一戸単位の立体化処理を地区内の全建物に対して、繰り返し処理を行う。
【００３１】
（２）建物情報に階数情報Ｆが含まれ図中「階数情報あり」の条件分岐で”ＹＥＳ”ならば、選択した建物の階数（ｎ）を取得する。もし、階数情報Ｆが無ければ階数情報補完ステップ２１において、どの様な建物であるかを推測し階数（ｎ）を推定する。建物階数（ｎ）の推定には、主用途情報Ｕと材質情報Ｍを基にした地区建物統計情報Ａ（表２参照。ここでは情報例１とする）を用いる。
【００３２】
【表２】

【００３３】
図４に階数情報補完ステップ２１の処理アルゴリズムにおける流れ図を示す。材質情報Ｍが既に有る場合、続いて当該建物の主用途が個人家屋、事業所、その他の中のどれであるかを判定する。いずれの建物の判定分岐についても基本的には木造か耐火構造であるのかの判定が含まれ、表２に示す階数分布に基づいて階数毎の確率計算が行われるのである。
【００３４】
図５に材質情報補完ステップ２４の処理アルゴリズムにおける流れ図を示す。材質情報Ｍを持たない建物については、材質情報補完ステップ２４において、主用途情報Ｕと階数情報Ｆから建物属性情報や該当地区の建物基準法、災害地区指定などの地域情報をもとにした地区建物統計情報（表３参照。ここでは情報例２とする）を用いて材質を推定する。例えば、個人住宅・２階建て以下ならば７０％の確率で木造とする。
【００３５】
【表３】

【００３６】
（３）建物の階数（ｎ）および建物の主用途Ｕ、材質Ｍ（特に木造／耐火材）をもとに、低層建築物か、中・高層建築物かを判定し、建物の１フロア当たりの高さ（ｈ’）を計算する。係る処理の流れは図６に示す。特に木造・２階建て以下ならば、そのほとんどが日本家屋であり、１フロア当たりの高さは地区建物統計情報Ａ（例えば一般的な日本家屋の高さ３ｍ）より求められる。
【００３７】
（４）建築物の高さ生成ステップ２３において、（２）、（３）で求めた階数（ｎ）と１フロア当たりの高さ（ｈ’）を乗算し、建物の高さ（ｈ）を求める。
【００３８】
（ｈ）＝（ｈ’）×（ｎ）
（５）２次元地図の建物情報より、各建物毎の底面形状を特定する。
【００３９】
（６）底面形状のＸ、Ｙ座標の値をそのままに、Ｚ座標の値を上記で求めた建物の高さ（ｈ）として仮の上面形状を作成する。
【００４０】
（７）係る上面と底面とを幾何的に繋いで側面を作成する。以上（５）〜（７）は立体形状生成ステップ２５にあたる。
【００４１】
（８）形状変更ステップ２６において、建物の主用途Ｕ・材質Ｍなどをもとに建物の特徴を予測し、建物の形状を変更する。例えば木造の個人住宅ならば、屋根形状生成対応表（表４参照）より、（７）までに生成した形状に寄棟屋根を追加する。
【００４２】
【表４】

【００４３】
（９）外装変更ステップ２７により、建物の主用途Ｕ・材質Ｍに合致した建物の色・外壁のテクスチャを色・テクスチャ情報Ｃから選び指定する。外装変更ステップ２７においては、以下の外装修飾対応表（表５参照）を用いる。
【００４４】
【表５】

【００４５】
図７は以上の様にして作成された立体化建物群７０を３次元表示装置によって表示した例である。紙面中央付近の２軒は木造の個人住宅７１であるため、切妻屋根・木材テクスチャで装飾し、紙面右手前の耐火材の個人住宅７２は、寄棟屋根・煉瓦テクスチャで装飾してある。周辺と最奥にある事業所７３、共同住宅７４は直方体形状・コンクリートのテクスチャとなっている。
【００４６】
図８では、中・高層ビル８１あるいは一般個人住宅８２、中低層の事業所８３といった建物の種類によって１フロア当たりの高さが可変生成してある様子をわかりやすく示した。以下、各建物毎の高さの算出内容について説明する。
個人住宅：
１フロア２．７ｍ×２階建て＋屋根１．８ｍ＝７．２ｍ（木造）
１フロア２．７ｍ×３階建て＋屋根１．８ｍ＝９．８ｍ（耐火構造）
事業所・共同住宅（５階建て以下）：
１フロア３．０×４階建て ＝１２．０ｍ
中・高層ビル（５階建て以上）：
１フロア４．０ｍ×２０階建て ＝８０．０ｍ
よって同じ３階でも、個人住宅９．８ｍ（軒下８．１ｍ）、事業所・共同住宅（５階建て以下）９．０ｍ、中・高層ビル１２ｍのように違う高さを表現できるのである。
【００４７】
＝＝＝標高修正アルゴリズム＝＝＝
上記に示した如く、２次元地図とそれに付随した建物情報とを基に作成された３次元建物データについて、電子地図の標高メッシュデータや紙ベースの地図などから対応箇所の標高値を読み取り、標高修正処理を施して地図上に配置するアルゴリズムを以下（１）〜（３）に示す。このような標高修正処理を施すには、３次元建物データの座標系と地形データの座標系とが例えば互いに平面直角座標系であるなど同一であるか、もしくは座標系が異なっていても座標変換公式を適用できるタイプであることが前提条件となる。
【００４８】
（１）処理対象となる建物底面の各頂点座標における標高を３次元地形データから抽出する（標高抽出ステップ）。
（２）標高抽出ステップにより抽出された標高のうち最高のものを当該建物の基準標高とし、建物底面以外の各頂点の高さ座標に加算する（建物高さ設定ステップ）。
（３）前記標高抽出ステップにより抽出された標高のうち最低のものを当該建物の底面標高とし、建物底面を構成する各頂点の高さ座標に加算する（建物底面高さ設定ステップ）。
【００４９】
これにより、参考にする地形データの標高メッシュ密度にもよるが、地表面の起伏変化である標高値の推移に適切に追随した３次元建物を地図上に表示することが可能となる。したがって、地図上に表示された３次元建物が地表下に沈み込んでいたり、逆に地表より浮き上がっていたりといった状況は起こり得ないのである。
【００５０】
＝＝＝防災情報提供システム＝＝＝
大規模地震等の被害甚大である災害においては建物の倒壊やそれに伴う火災などが広域的かつ同時多発的に発生することが予想される。このような災害の発生に先立ち、予め災害発生シュミレーションを行うことは住民の避難誘導や消防並びに自衛隊等の消火救助活動などを迅速かつ効率的に行うために非常に有意義である。また、事前のシュミレーションのみにとどまらず、実際に災害が発生した場合でもその時点で各所で得られた被害状況のデータを適宜取り込んで被害予想を立てることも重要である。
【００５１】
このような観点から、上述した本発明の３次元地図作成方法を実施することで作成された３次元地図を用いた防災情報提供システムを以下に説明する。なお、この防災情報提供システムの実施例については特に図示しない。
【００５２】
前記防災情報提供システムは、各建物の用途、構造、階数、材質といった情報を示す建物情報表示機能と、建物毎の火災や倒壊の進行度を経時的に色別表示する損害表示機能とを備えるシステムである。実際には、図２で示した流れ図の中で立体形状生成ステップ２５までで作成された立体化建物について建物毎に屋根形状を特徴づけたり（形状変更ステップ２６により例えば個人住宅なら寄棟や切妻屋根にする）、壁面に建物材質を象徴するテクスチャ（外装変更ステップ２７において例えば木造なら木目テクスチャ、レンガ壁ならレンガテクスチャ）を施すことにより、３次元地図上で表示された各建物の高さ、材質、用途、構造が一見しただけで総合的に理解可能になっている（建物情報表記機能）。
【００５３】
また、上記の如く作成された３次元地図において、建物の材質や構造等に応じた火災発生率、燃焼速度及び延焼度合い、或いは倒壊の可能性や進行程度を経時的に適宜シュミレーションし（これには災害発生に先立って予め行われる場合と実際の災害発生に即して行われる場合とがある）、その結果を反映させて建物毎に火災や倒壊等の進行度を色別表示する（損害表示機能）。色別表示するにあたっては、例えば火災が進行しついに鎮火するに至った建物については黒色、現在燃焼開始直後であれば橙色、燃焼中であれば赤色、火災未発生であれば黄色といった色分けを行うこととする。或いは模様が加味されていてもよい。
【００５４】
【発明の効果】
本発明によれば、多数の人員を配置したデータ入力作業や長期間の共同作成作業を行うことなく、迅速かつ安価に実際の街並みに近い精密な３次元地図を作成できる。この３次元地図作成に際して行われる各作業は、主にコンピュータプログラムによる自動生成によるため、人為的なオペレーションミス等を抑止することにもつながる。
【００５５】
また、例えば一般木造建築には切妻屋根、鉄筋コンクリート造の個人住宅なら寄棟形式、高層ビルなら平屋根というように、建物の属性に応じて特徴的な形状を地図上の各建物に適宜採用することが可能で、加えて建物外壁の色・テクスチャ等の外装に関しても主用途や素材といった建物の属性に応じて使い分けることが出来る。これにより本発明の作成方法により作成された３次元地図は視覚的に非常にわかりやすく、その利用者は一見して対象建物の詳細について推測することが出来るのである。
【００５６】
加えて、本発明においては地形データの標高値に即して建物高さを修正可能であるため、地形データと３次元建物データとの高さ座標における整合性が著しく良好である。したがって、普通の平地地形のみならず地形の起伏が比較的大きい箇所においてさえも３次元地図上では全く問題なく３次元建物と地表高との高さ関係が正確に表現されることになる。
【００５７】
そして、本発明の防災情報提供システムによれば、広域的に俯瞰できる３次元地図において、建物情報や色分けされた損害表示をもって一見して明確な災害情報を、本システム利用者に確実に提供することが可能である。加えて、災害の予測だけでなく、被害の及んでいない地域や経路を選定して消防や救助手段を効率的かつ迅速安全に誘導配置するといったことも可能となる。
【図面の簡単な説明】
【図１】建物立体化の従来手法概要を示す説明図である。
【図２】本発明の３次元地図作製方法における建物立体化の処理システムを示す説明図である。
【図３】本発明の３次元地図作成方法における主処理アルゴリズムを示す流れ図である。
【図４】階数情報補完ステップの処理アルゴリズムを示す流れ図である。
【図５】材質情報補完ステップの処理アルゴリズムを示す流れ図である。
【図６】建物１フロア当たりの高さを計算する処理概要を示す流れ図である。
【図７】本発明の３次元地図作成方法により作成された立体化建物群の一例を示した説明図である。
【図８】建物種類毎に１フロア当たりの高さを可変生成した状況を示す説明図である。
【符号の説明】
Ｍ 材質情報
Ｕ 主用途
Ｂ 底面形状（床面積）
Ａ 地区建物統計情報（階数統計情報）
ｎ 階数
２１ 階数情報補完ステップ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for creating a three-dimensional map, and more particularly to an apparatus and method for creating a three-dimensional map based on a two-dimensional map and accompanying building information.
[0002]
[Prior art]
Electronic maps have been used in a wide range of fields, such as car navigation systems and computer map searches, to replace traditional paper-based maps. Initially, this electronic map is mainly a two-dimensional map. By reading a paper-based map such as a map issued by the Geospatial Information Authority of Japan or a city planning map with a scanner (optical reader), the coordinate points of each site shape etc. in the map The creation method of extracting the data on a computer was adopted.
[0003]
On the other hand, in recent years, the situation has been promoted to make the electronic map three-dimensional. When creating a three-dimensional map from a two-dimensional map, if the target area is an urban area, for example, not only general landforms such as the height of land but also three-dimensional buildings are required. When building a building, information on the height of each building is required.
[0004]
There are roughly two ways to obtain the building height information. One is a method of collecting information for each house directly by conducting a field survey. The other is a method using the floor information of a building attached to a two-dimensional electronic map. Some 2D electronic maps have not only the coordinate data of the bottom shape of topography, roads, buildings, etc., but also attribute information such as the address of each building, the name of the householder, the number of floors, and the main usage. Of these, the floor information is used to three-dimensionalize the building.
[0005]
Hereinafter, an outline of a three-dimensional building procedure using the floor information will be described. An outline of the conventional method for building a three-dimensional building is shown in FIG.
(1) A building to be three-dimensionalized is selected from a two-dimensional electronic map.
(2) The floor number of the building is acquired from the floor database 10 in which the attribute information of the selected building is stored.
(3) In the building height generation step 11, the building height is calculated by simply multiplying the floor of the building by 3 m.
(4) Buildings that do not have floor information in the electronic map shall be 2 stories high 6m high.
[0006]
(5) Identify the bottom shape of the building.
(6) The top surface shape is created with the XY coordinate value of the bottom surface shape as it is and the Z coordinate value as the height obtained in step (3) or (4).
(7) In the three-dimensional shape generation step 12, the building side surface is created so as to connect the upper surface and the bottom surface while referring to the shape data in the component shape database 13. The created three-dimensional data is stored and saved in the solid shape information database 14.
The conventional three-dimensional map is often created by the above procedure.
[0007]
[Problems to be solved by the invention]
However, the conventional three-dimensional map creation method has the following problems.
That is, in the method of directly collecting information for each house by conducting a field survey, it is necessary to investigate the height of each building ranging from several hundred to several thousand, depending on the scale of the map to be created. Therefore, the personnel required for this work are large and the survey period is often long. In addition, it is necessary to arrange a large number of personnel for creating the actual map by processing the data obtained in this survey. In other words, it is unavoidable that the period and labor cost required to create a 3D map are unavoidable, and in addition, there is a qualitative problem that the level of the created map varies depending on the work skills of each creator. .
[0008]
On the other hand, in the method of creating a three-dimensional map by creating a three-dimensional map by using the floor information of the building attached to the two-dimensional electronic map, all the buildings that do not have the floor information necessary for the three-dimensionalization have a predetermined number of floors ( 2 floors). Therefore, for example, even if the building is expected to be more than 5 stories more easily than the building structure, floor area, etc., the height is calculated as 2 stories. Therefore, the display on the three-dimensional map and the actual building height are greatly different, and the utility value and efficiency of the map itself are greatly reduced.
[0009]
In addition, because the building height is calculated by multiplying the number of floors by the height per floor (for example, 3m) uniformly regardless of the type of building, such as a high-rise building with 20 stories or more and a general building with one-story building, It is difficult to accurately reflect the actual height of the building on the map. Therefore, for example, in the case of a 20-story building, there is a problem in that the actual height of 80 m is 60 m in the calculation according to the conventional method, which causes a large difference.
[0010]
In addition to the above-described problem, there is a case where the consistency with the terrain data is a problem in such a problem of the difference between the building height on the map and the actual height. This is a problem that tends to appear in places where terrain undulations are relatively large, such as hilly areas, and where elevation data at that location must be referenced in detail when creating a map. For example, the bottom of a three-dimensional building on a map Will rise from the ground surface, and conversely, the ground height will be inconsistent with the building height coordinates, for example, the building will be buried under the ground surface. In either case, the building height was not corrected according to the elevation value of the topographic data.
[0011]
Therefore, the present invention has been made paying attention to such a conventional problem, and provides a three-dimensional map creation method that can automatically and quickly create three-dimensional data of a building close to an actual cityscape at a low cost. Is.
[0012]
[Means for Solving the Problems]
The 3D map creation method of the present invention that achieves the above object arranges the 3D building data created on the basis of the 2D map and the building information attached thereto by performing an altitude correction process according to the actual landform, A computer that creates a three-dimensional map extracts an elevation at each vertex coordinate of the bottom of the building to be processed from the three-dimensional terrain data stored in the database, and the elevation extracted by the elevation extraction step. The highest one of them is used as the reference elevation of the building and added to the height coordinates of each vertex other than the bottom of the building, and the lowest of the elevations extracted by the elevation extraction step and the bottom elevation, and executes the building bottom height setting step of adding to the height coordinate of each vertex constituting the building bottom, a.
[0013]
In addition, the computer-readable recording medium on which the 3D map creation program of the present invention is recorded is an altitude correction process based on the actual topography for the 3D building data created based on the 2D map and the building information associated therewith. On a computer that creates and 3D maps
The altitude extraction step for extracting the altitude at each vertex coordinate of the bottom surface of the building to be processed from the 3D terrain data stored in the database, and the highest one of the altitudes extracted by the altitude extraction step as the standard of the building A building height setting step to be added to the height coordinates of each vertex other than the building bottom, and the lowest one of the elevations extracted by the elevation extracting step is set as the bottom elevation of the building to constitute the building bottom A building bottom height setting step for adding to the height coordinates of each vertex is recorded, and a three-dimensional map creation program is executed.
[0014]
In addition, the 3D map creation system of the present invention is a 3D map creation that arranges the 3D building data created based on the 2D map and the accompanying building information after performing altitude correction processing according to the actual topography. An altitude extraction means for extracting the elevation at each vertex coordinate of the building bottom to be processed from the three-dimensional terrain data stored in the database, and the highest one of the elevations extracted by the elevation extraction means As the reference elevation of the building, and the building height setting means for adding to the height coordinates of each vertex other than the building bottom, and the lowest one of the elevations extracted by the elevation extraction means as the bottom elevation of the building, Building bottom height setting means for adding to the height coordinate of each vertex constituting the building bottom.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 is an explanatory diagram showing a building three-dimensional processing system in the three-dimensional map creation method of the present invention. An example of building data used by the processing system is shown in Table 1.
[0020]
[Table 1]

[0021]
Using the building data attached to the 2D electronic map is more efficient in creating 3D maps from the perspective of ensuring consistency between the various data, but depending on the situation, importing from other media is also possible. .
The data includes information such as a unique number for each building, coordinate values in the map, address, building name, building type, floor number, and material, and is stored in a database so that it can be searched, organized, and stored. These pieces of information become basic information for the map three-dimensional work.
[0022]
Next, the processing system of the 3D map creation method of the present invention shown in FIG. 2 will be outlined. If the building information of the 2D map used as a base for creating the 3D map does not include floor information, or if it does not include all the buildings, the floor information supplementing step 21 in the present invention is used. . In this step, the building type of each building on the two-dimensional map is determined based on at least one of the building material information M, main usage information U, and floor area (bottom shape information B) included in the building information. The material is estimated, and the floor number of the building is determined by probability calculation based on the building type and the floor statistical information for each material (district building statistical information A).
[0023]
If the material information M is not obtained, the floor information F of the building included in the building information, and the regional information such as the Building Standard Act or disaster area designation that specifies the number of floors and structure of the building in the area Thus, the material of each building is estimated (referred to as material information complementing step 24). At this point, for each building, the type of building such as low-rise / medium / high-rise establishments and individual houses, the material such as wooden or refractory material, and the number of floors are determined.
[0024]
If the floor information F of the building is included in the building information from the beginning or the floor number is determined by the floor information supplementing step 21 as described above, the height per floor can be changed according to the type of building. Determine in step 22. Here, the height information per floor obtained in advance from the district building statistical information A or the like is reflected for each building type for each building.
[0025]
Next, the bottom shape of each building shown in the two-dimensional map is extracted from the bottom shape information B, and it is finally combined with the data such as the already determined building type, material, number of floors, and height per floor. Is three-dimensionalized. Although details will be described later, basically, an upper surface (roof portion) facing the bottom surface is created, and a side wall is created for each of the contact sides.
[0026]
At this time, based on the main use U and material information M of the building and the building shape information (part shape P) or building exterior information (color / texture information C) for each predetermined main use U and material M, 3 The shape or exterior of each building to be dimensioned can be varied (shape change step 26 and exterior change step 27). The shape change mainly refers to a roof shape. For example, in the case of a Japanese style wooden building, a roof such as a gable or a dormitory is selected. The exterior change refers to, for example, a texture of wood for a wooden structure and a concrete-like texture for a side wall of a refractory according to the material of the building.
[0027]
The three-dimensional data of the building thus created is stored and accumulated as three-dimensional shape information S, and is integrated with other data as a three-dimensional map.
[0028]
Each mechanism described above is mainly composed of a database storing various information and a computer linked to them.
[0029]
=== Main algorithm ===
The main processing algorithm for implementing the 3D map creation method of the present invention is shown in FIG. 3, and the building 3D procedure according to this is shown in (1) to (8).
[0030]
(1) Designate a three-dimensional area and perform a three-dimensional process on all buildings in the area. Such one-unit three-dimensional processing is repeated for all buildings in the district.
[0031]
(2) If the floor information F is included in the building information and “YES” is selected in the conditional branch of “with floor information” in the figure, the floor number (n) of the selected building is acquired. If the floor information F is not present, the floor information complementing step 21 estimates what kind of building it is and estimates the floor (n). For the estimation of the number of building floors (n), district building statistical information A (see Table 2 based on the main usage information U and material information M) is used.
[0032]
[Table 2]

[0033]
FIG. 4 shows a flowchart in the processing algorithm of the floor information complementing step 21. If the material information M already exists, it is subsequently determined whether the main use of the building is an individual house, a business place, or the like. The determination branch of any building basically includes determination of whether it is a wooden structure or a fireproof structure, and the probability calculation for each floor is performed based on the floor distribution shown in Table 2.
[0034]
FIG. 5 shows a flowchart in the processing algorithm of the material information complementing step 24. For buildings that do not have material information M, in the material information supplementing step 24, the district is based on regional information such as building attribute information, building standard law of the corresponding district, disaster area designation, etc. from main usage information U and floor information F The material is estimated using building statistical information (refer to Table 3; here, information example 2). For example, if it is a private house, 2 stories or less, it will be wooden with a probability of 70%.
[0035]
[Table 3]

[0036]
(3) Based on the number of floors (n) of the building and the main use U of the building, material M (especially wooden / refractory materials), it is determined whether it is a low-rise building or a middle / high-rise building. The height (h ′) of is calculated. The flow of such processing is shown in FIG. Especially if it is less than wooden and 2 stories, most of them are Japanese houses, and the height per floor is obtained from the district building statistical information A (for example, the height of a typical Japanese house is 3 m).
[0037]
(4) In the building height generation step 23, the number of floors (n) obtained in (2) and (3) is multiplied by the height (h ′) per floor, and the building height (h) is obtained. Ask.
[0038]
(H) = (h ′) × (n)
(5) The bottom shape of each building is specified from the building information of the two-dimensional map.
[0039]
(6) A temporary top surface shape is created using the X and Y coordinate values of the bottom surface shape as they are, and the Z coordinate value as the height (h) of the building obtained above.
[0040]
(7) A side surface is created by geometrically connecting the top surface and the bottom surface. The above (5) to (7) correspond to the three-dimensional shape generation step 25.
[0041]
(8) In the shape change step 26, the characteristics of the building are predicted based on the main use U / material M of the building, and the shape of the building is changed. For example, in the case of a wooden private house, a dormitory roof is added to the shape generated up to (7) from the roof shape generation correspondence table (see Table 4).
[0042]
[Table 4]

[0043]
(9) In the exterior change step 27, the color of the building and the texture of the outer wall matching the main use U and material M of the building are selected from the color / texture information C and designated. In the exterior change step 27, the following exterior modification correspondence table (see Table 5) is used.
[0044]
[Table 5]

[0045]
FIG. 7 shows an example in which the three-dimensional building group 70 created as described above is displayed by a three-dimensional display device. Since the two houses near the center of the page are wooden private houses 71, they are decorated with a gable roof / wood texture, and the refractory personal houses 72 on the right front of the page are decorated with a laid roof / brick texture. The business establishment 73 and the apartment house 74 in the periphery and the innermost part have a rectangular parallelepiped shape and a concrete texture.
[0046]
FIG. 8 shows the state in which the height per floor is variably generated depending on the type of building, such as a medium / high-rise building 81, a general private house 82, or a medium / low-rise establishment 83. Hereinafter, the calculation content of the height for each building will be described.
Private housing:
1 floor 2.7m x 2 stories + roof 1.8m = 7.2m (wooden)
1 floor 2.7m x 3 stories + roof 1.8m = 9.8m (fireproof structure)
Office / Apartment house (5 stories or less):
1 floor 3.0 x 4 stories = 12.0m
Medium and high-rise buildings (more than 5 stories):
1 floor 4.0m x 20 stories = 80.0m
Therefore, even on the same 3rd floor, different heights can be expressed, such as individual housing 9.8m (8.1m under the eaves), office / communal housing (5 stories or less) 9.0m, and middle / high-rise building 12m.
[0047]
=== Altitude correction algorithm ===
As shown above, for the 3D building data created based on the 2D map and the building information attached to it, the altitude value of the corresponding location is read from the altitude mesh data of the electronic map or the paper-based map. The algorithms (1) to (3) below show the algorithm for performing correction processing and placing the map on the map. In order to perform such elevation correction processing, the coordinate system of the three-dimensional building data and the coordinate system of the terrain data are the same, such as a plane rectangular coordinate system, or coordinate conversion is performed even if the coordinate systems are different. The precondition is that the type is applicable to the formula.
[0048]
(1) The elevation at each vertex coordinate on the bottom of the building to be processed is extracted from the three-dimensional terrain data (elevation extraction step).
(2) The highest elevation extracted in the elevation extraction step is set as the reference elevation of the building, and is added to the height coordinates of each vertex other than the building bottom (building height setting step).
(3) The lowest one of the elevations extracted in the elevation extraction step is set as the bottom elevation of the building, and added to the height coordinates of each vertex constituting the building bottom (building bottom height setting step).
[0049]
Thereby, although it depends on the altitude mesh density of the terrain data to be referred to, it is possible to display on the map a three-dimensional building that appropriately follows the altitude value transition that is the undulation change of the ground surface. Therefore, a situation in which the three-dimensional building displayed on the map is sinking under the ground surface, or conversely, is floating above the ground surface cannot occur.
[0050]
=== Disaster prevention information provision system ===
In disasters such as large-scale earthquakes, it is expected that buildings will collapse and fires accompanying them will occur over a wide area and at the same time. Prior to the occurrence of such a disaster, conducting a disaster occurrence simulation in advance is very meaningful in order to promptly and efficiently perform evacuation guidance for residents, fire fighting and fire fighting rescue activities such as the Self-Defense Forces, and the like. It is also important not only to conduct preliminary simulations, but also to make damage predictions by appropriately importing data on the damage situation obtained at each point even when a disaster actually occurs.
[0051]
From such a point of view, a disaster prevention information providing system using a 3D map created by implementing the 3D map creation method of the present invention described above will be described below. In addition, it does not show in particular about the Example of this disaster prevention information provision system.
[0052]
The disaster prevention information provision system has a building information display function that shows information such as the use, structure, floor number, and material of each building, and a damage display function that displays the progress of fire and collapse for each building by color over time. System. Actually, in the flowchart shown in FIG. 2, the roof shape of each of the three-dimensional buildings created up to the three-dimensional shape generation step 25 is characterized (for example, in the case of a private house, a dormitory or a gable is formed by the shape change step 26). The height of each building displayed on the three-dimensional map by applying a texture symbolizing the building material on the wall surface (for example, a wood texture for a wooden structure, a brick texture for a brick wall) in the exterior modification step 27, It is possible to understand comprehensively just by looking at the material, usage, and structure (building information notation function).
[0053]
In addition, in the three-dimensional map created as described above, the fire occurrence rate, the burning rate and the degree of fire spread, or the possibility of collapse and the degree of progression according to the material and structure of the building are simulated as appropriate over time. May be performed in advance prior to the occurrence of a disaster, or may be performed in accordance with the actual occurrence of a disaster), and the progress of a fire or collapse will be displayed in different colors for each building reflecting the result (damage Display function). When displaying by color, for example, black is used for buildings where fires have progressed and finally extinguished, orange if immediately after the start of combustion, red if burning, and yellow if no fire has occurred. I will do it. Alternatively, a pattern may be added.
[0054]
【The invention's effect】
According to the present invention, it is possible to quickly and inexpensively create a precise three-dimensional map close to an actual cityscape without performing a data input operation in which a large number of people are arranged or a long-term joint creation operation. Since each work performed in creating the three-dimensional map is mainly based on automatic generation by a computer program, it also leads to suppression of an artificial operation error or the like.
[0055]
Also, for example, gable roofs for general wooden buildings, dormitory forms for reinforced concrete individual houses, flat roofs for high-rise buildings, etc. In addition, the exterior, such as the color and texture of the building outer wall, can be used according to the attributes of the building such as the main purpose and material. Thereby, the three-dimensional map created by the creation method of the present invention is very easy to understand visually, and the user can guess the details of the target building at first glance.
[0056]
In addition, in the present invention, since the building height can be corrected in accordance with the elevation value of the terrain data, the consistency in the height coordinate between the terrain data and the three-dimensional building data is remarkably good. Therefore, the height relationship between the three-dimensional building and the ground surface can be accurately expressed on the three-dimensional map without any problem even in a portion where the terrain is relatively large as well as the ordinary flat land.
[0057]
According to the disaster prevention information provision system of the present invention, in a three-dimensional map that can be viewed over a wide area, it is possible to reliably provide clear disaster information to the system user at first glance with building information and color-coded damage display. It is possible. In addition, it is possible not only to predict disasters, but also to select areas and routes that do not cause damage and guide and arrange firefighting and rescue means efficiently and quickly.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an outline of a conventional method for building a building.
FIG. 2 is an explanatory diagram showing a three-dimensional building processing system in the three-dimensional map creation method of the present invention.
FIG. 3 is a flowchart showing a main processing algorithm in the three-dimensional map creation method of the present invention.
FIG. 4 is a flowchart showing a processing algorithm of a floor information complementing step.
FIG. 5 is a flowchart showing a processing algorithm of a material information complementing step.
FIG. 6 is a flowchart showing an outline of processing for calculating a height per floor of a building.
FIG. 7 is an explanatory diagram showing an example of a three-dimensional building group created by the three-dimensional map creation method of the present invention.
FIG. 8 is an explanatory diagram illustrating a situation in which the height per floor is variably generated for each building type.
[Explanation of symbols]
M Material information U Main application B Bottom shape (floor area)
A district building statistics information (floor statistics information)
n Number of floors 21 Number of floors information supplement step

Claims (3)

A computer that creates a 3D map by arranging altitude correction processing according to the actual topography for 3D building data created based on the 2D map and the building information attached thereto ,
An altitude extraction step for extracting the altitude at each vertex coordinate of the bottom of the building to be processed from the 3D terrain data stored in the database ;
A building height setting step in which the highest one of the elevations extracted by the elevation extraction step is set as the reference elevation of the building, and added to the height coordinates of each vertex other than the building bottom,
The lowest one of the elevations extracted by the elevation extraction step is the bottom elevation of the building, and the building bottom height setting step is added to the height coordinates of each vertex constituting the building bottom,
A method for creating a three-dimensional map, comprising: To the computer that creates the 3D map by arranging the 3D building data created on the basis of the 2D map and the accompanying building information by applying the elevation correction process according to the actual topography,
  An altitude extraction step for extracting the altitude at each vertex coordinate of the bottom of the building to be processed from the 3D terrain data stored in the database;
  A building height setting step in which the highest one of the elevations extracted by the elevation extraction step is set as the reference elevation of the building, and added to the height coordinates of each vertex other than the building bottom,
  The lowest one of the elevations extracted by the elevation extraction step is the bottom elevation of the building, and the building bottom height setting step is added to the height coordinates of each vertex constituting the building bottom,
  The computer-readable recording medium which recorded the three-dimensional map creation program which performs this. A 3D map creation system that arranges altitude correction processing according to actual terrain for 3D building data created based on a 2D map and building information attached thereto,
  Altitude extraction means for extracting the altitude at each vertex coordinate of the bottom of the building to be processed from the three-dimensional terrain data stored in the database;
  A building height setting means for setting the highest one of the elevations extracted by the elevation extraction means as the reference elevation of the building and adding it to the height coordinates of each vertex other than the bottom of the building;
  The lowest one of the elevations extracted by the elevation extraction means is the bottom elevation of the building, and the building bottom height setting means adds to the height coordinates of each vertex constituting the building bottom,
  A three-dimensional map creation system comprising:

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