JP4160406B2 - Three-dimensional shape processing apparatus, curve projection method, program, and storage medium - Google Patents

Three-dimensional shape processing apparatus, curve projection method, program, and storage medium Download PDF

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JP4160406B2
JP4160406B2 JP2003005033A JP2003005033A JP4160406B2 JP 4160406 B2 JP4160406 B2 JP 4160406B2 JP 2003005033 A JP2003005033 A JP 2003005033A JP 2003005033 A JP2003005033 A JP 2003005033A JP 4160406 B2 JP4160406 B2 JP 4160406B2
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curve
cylindrical surface
projection
projected
plane
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JP2004220202A (en
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直之 佐藤
正範 原田
智 火口内
佐藤　　淳
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Ricoh Co Ltd
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Ricoh Co Ltd
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Description

【０００１】
【発明の属する技術分野】
本発明は、ＣＡＤ／ＣＡＭ装置など専用の３次元形状処理装置やパーソナルコンピュータなど汎用の情報処理装置を用いた曲線投影処理に係わり、特に、曲線を円柱面に対して法線方向に投影する曲線投影処理に関する。
【０００２】
【従来の技術】
グラフィクス表示装置とコンピュータを用いたＣＡＤ／ＣＡＭ装置などでは、従来、次のような手順により、３次元立体の曲面の上方にある曲線を曲面に対して法線方向に投影していた。なお、前記３次元立体とは、例えば境界表現形式のソリッドモデルデータとして生成された形状を指し、境界表現形式のソリッドモデルとは、稜線や頂点や面というような要素により３次元空間上に閉じた領域を定義し、中身の詰まった立体を表現したものである。
（１）曲線から、その両端点を含む幾つかの点を抽出し、それぞれの点から曲面上に垂線を下ろす（図６参照）。
（２）曲面上に下ろされた垂線の曲面上の点を滑らかにつなぎ、曲面上に乗る曲線（投影曲線）を生成する（図９参照）。
つまり、投影された幾つかの点をつないで曲線を生成することにより、近似的に曲線を投影するのである。しかしながら、前記した従来技術においては、点が曲面上に投影できるかどうかを考慮せずに曲線全体から点を抽出していたので、投影できない点が抽出された場合は、他に投影できる点が存在してもその曲線を曲面に投影できなかった（図１０参照）。
【０００３】
前記したように、従来技術においては、投影できない点が抽出された場合は、他の投影できる点が存在してもその曲線を曲面に投影できなかった。また、曲線が円柱面の磁区と交差したり重なったりすると、そのような箇所から抽出された点より下ろされる垂線は一意に定まらず、そのため、求めようとする投影曲線が定まらないという問題についても考慮されていなかった（図１１参照）。
本発明の目的は、このような従来技術の問題を解決することにあり、具体的には、投影する曲面が円柱面であり、且つ、その円柱面の、２つの母線によって区切られた中心角１８０度以内の区間に対して投影する場合に、曲線上の投影可能な部分を調べ、投影可能な部分について投影曲線を求めることができる３次元形状処理装置、曲線投影方法、プログラム、および記憶媒体を提供することにある。また、曲線が円柱面の軸と交差したり重なったりすると、そのような箇所から抽出される点より下ろされる垂線は一意に定まらず、そのため、求めようとする投影曲線が定まらないという問題についても考慮する。
【０００４】
【課題を解決するための手段】
前記の課題を解決するために、請求項１記載の発明では、曲線を円柱面に対して法線方向に投影する３次元形状処理装置において、前記円柱面の一方の一端の境界線であり該円柱面の軸と平行な直線である第１の母線と、他の一方の一端の境界線であり該円柱面の軸と平行な直線である第２の母線とによって区切られた中心角１８０度以内の区間に対して曲線を投影する際に、前記第１の母線と軸が乗る第１の平面と、前記第２の母線と軸が乗る第２の平面とを生成する平面生成手段と、投影しようとする曲線について、前記平面生成手段により生成された２つの平面の両方における、円柱面の存在する側に存在する曲線の部分を投影可能な部分とし、生成された２つの平面のうちの少なくとも一方における、円柱面の存在しない側にある曲線の部分を投影可能でない部分として分割する曲線分割手段と、前記曲線分割手段により分割された投影可能な部分から両端点を含む幾つかの点を抽出し、抽出した各点から円柱面上に投影曲線を生成する投影曲線生成手段とを備えた。
また、請求項２記載の発明では、曲線を円柱面に対して法線方向に投影する３次元形状処理装置における曲線投影方法において、前記円柱面の一方の一端の境界線であり該円柱面の軸と平行な直線である第１の母線と、他の一方の一端の境界線であり該円柱面の軸と平行な直線である第２の母線とによって区切られた中心角１８０度以内の区間に対して曲線を投影する際に、前記第１の母線と軸が乗る第１の平面と、前記第２の母線と軸が乗る第２の平面とを生成する平面生成工程と、投影しようとする曲線について、前記平面生成工程で生成された２つの平面の両方における、円柱面の存在する側に存在する曲線の部分を投影可能な部分とし、生成された２つの平面のうちの少なくとも一方における、円柱面の存在しない側にある曲線の部分を投影可能でない部分として分割する曲線分割工程と、前記曲線分割工程で分割された投影可能な部分から両端点を含む幾つかの点を抽出し、抽出した各点から円柱面上に投影曲線を生成する投影曲線生成工程とを有する構成にした。
また、請求項３記載の発明では、請求項２記載の曲線投影方法において、前記曲線中に投影曲線が一意に定まらない部分を含むか否かを調べ、含まない場合のみ、投影曲線を求める構成にした。
また、請求項４記載の発明では、請求項３記載の曲線投影方法において、円柱面の軸と前記曲線とが交差するか否かを調べ、交差する場合、その曲線は曲線中に投影曲線が一意に定まらない部分を含む曲線であるとして、投影曲線を求めないで処理を終了する構成にした。
また、請求項５記載の発明では、請求項３記載の曲線投影方法において、円柱面の軸と前記曲線とが重なる否かを調べ、重なる場合、その曲線は曲線中に投影曲線が一意に定まらない部分を含む曲線であるとして、投影曲線を求めないで処理を終了すること構成にした。
また、請求項６記載の発明では、コンピュータに請求項２乃至請求項５のいずれか１項に記載の曲線投影方法における各工程を実行させるためのプログラムとした。
また、請求項７記載の発明では、請求項６記載のプログラムを記憶したコンピュータ読取可能な記憶媒体とした。
【０００５】
【発明の実施の形態】
以下、図面により本発明の実施の形態を詳細に説明する。
図２は本発明の一実施例を示す３次元形状処理装置の構成ブロック図である。図示したように、この実施例の３次元形状処理装置は、この装置全体を制御するシステム制御部１、本発明に係わる曲線投影処理など、取得した３次元形状データを処理する３次元形状処理部２、３次元形状データやプログラムなどを記憶しておく外部記憶装置（例えばハードディスク装置）３、３次元形状データに従って３次元立体形状を表示するグラフィク表示装置４、３次元立体形状などを紙上に出力するプロッタ５、キーボードやマウスやテキスト表示装置などを有した操作表示部６、ネットワークを介して外部から３次元形状データを取得したりする通信制御部７などを備えている。
なお、前記システム制御部１および３次元形状処理部２は、本発明に係わるプログラムや各種データを一時的に記憶するメモリ（例えばＲＡＭ）およびそのプログラムに従って動作するＣＰＵを有する。また、この実施例においては、請求項１記載の平面生成手段、曲線分割手段、および投影曲線生成手段が前記３次元形状処理部２により実現される。
このような構成で、この実施例の３次元形状処理装置では、３次元立体形状を構成している円柱面上の曲線を、その円柱面の、２つの母線によって区切られた中心角１８０度以内の区間に対して投影する際に、曲線上の投影可能な部分を調べ、その投影可能な部分について投影曲線を求める（生成する）。
【０００６】
図１に、本発明の一実施例の動作フローを示す。以下、図１に従って、この実施例の動作フローを説明する。
まず、３次元形状処理部２が図３に示したような平面ａを作成する（Ｓ１）。つまり、円柱面（図示の例では凹曲面）の軸ｃとその円柱面の一方の母線（円柱面の一端の境界線であり、軸ｃと平行な直線である）とが乗る平面ａを作成するのである（図３：円柱面の軸方向から見た図参照）。さらに、３次元形状処理部２はもう一方の母線と円柱面の軸ｃが乗る平面ｂも作成する（図３参照）（Ｓ２）。なお、平面に乗っている母線に着目し、円柱面の存在する側を平面の裏側、円柱面の存在しない側を平面の表側とする。
続いて、３次元形状処理部２は、投影しようとする曲線について、作成した２枚の平面のどちらの裏側にも存在する部分（図４に示したＡの部分）と、少なくともどちらか一方の表側に存在する部分（図４に示したＢ の部分）とに曲線を分ける（Ｓ３）。なお、曲線が前記平面と交叉する部分については裏側に存在するとみなす。
こうして、前記曲線に前記Ａの部分が存在し、且つ、その部分が円柱の軸と交差したり重なったりしていなければ、その部分は投影可能であると判定する（図５参照）（Ｓ４でＹｅｓ）。前記曲線が前記平面と交叉する点は投影可能部分とされた端であるが、その点から前記円柱面に対してその曲面の法線方向に下ろす直線は前記平面に乗っているので、その直線と曲面（円柱面）が交叉する点は曲面からはみ出ないのである。なお、曲線中に円柱の軸と交差したり重なったりする投影曲線が一意に定まらない部分を含む場合、投影曲線を求めないでこの動作フローを終了させる。
続いて、３次元形状処理部２は、投影可能とみなされた前記Ａ部分について、その部分の両端点を含む幾つかの点を抽出し（Ｓ５）、それぞれの点から円柱面上に垂線を下ろす（図６参照）（Ｓ６）。さらに、曲面上に下ろされた複数の垂線の足（垂線の円柱曲面上の点）を滑らかにつなぎ（Ｓ７）、投影可能部分の投影曲線を生成する。
一方、ステップＳ４において投影可能部分がないと判定された場合には（Ｓ４でＮｏ）、その時点でこの動作フローを終了させる。
こうして、この実施例によれば、投影可能な部分のみ投影曲線を生成するようにできるので、投影する曲線上のたまたま抽出された点から垂線を下ろせないからと言って、他に投影できる点が存在するにもかかわらず、その曲線のいずれの部分も曲面に投影できなくなってしまうというような不具合を解消することができる。
【０００７】
以上、本発明の投影曲線生成方法を凹曲面の円柱面の図面を用いて説明したが、凸曲面の円柱面の場合にも同様に実施することができる。図７および図８に凸曲面の円柱面の場合の説明図を示しておく。図７は図３に対応し、図８は図４に対応している。
また、説明したような曲線投影方法に従ってプログラミングしたプログラムを例えば着脱可能な記憶媒体に記憶し、その記憶媒体をこれまで本発明によった曲線投影をおこなえなかったパーソナルコンピュータなど情報処理装置に装着することにより、または、そのようなプログラムをネットワークを介してそのような情報処理装置へ転送することにより、そのような情報処理装置においても本発明によった曲線投影をおこなうことができる。
【０００８】
【発明の効果】
以上説明したように、本発明によれば、請求項１記載の発明では、円柱面の一方の一端の境界線であり該円柱面の軸と平行な直線である第１の母線と、他の一方の一端の境界線であり該円柱面の軸と平行な直線である第２の母線とによって区切られた中心角１８０度以内の区間に対して、曲線を法線方向に投影する際、第１の母線と軸が乗る第１の平面と、第２の母線と軸が乗る第２の平面とを生成し、投影しようとする曲線について、生成された２つの平面の両方における、円柱面の存在する側に存在する曲線の部分を投影可能な部分とし、生成された２つの平面のうちの少なくとも一方における、円柱面の存在しない側にある曲線の部分を投影可能でない部分として分割し、分割された投影可能な部分から両端点を含む幾つかの点を抽出し、抽出した各点から円柱面上に投影曲線を生成することができるので、投影できない部分が抽出された場合、他に投影できる点が存在してもその曲線を投影できないという問題を解決することができる。
また、請求項２記載の発明では、円柱面の一方の一端の境界線であり該円柱面の軸と平行な直線である第１の母線と、他の一方の一端の境界線であり該円柱面の軸と平行な直線である第２の母線とによって区切られた中心角１８０度以内の区間に対して、曲線を法線方向に投影する際、第１の母線と軸が乗る第１の平面と、第２の母線と軸が乗る第２の平面とを生成し、投影しようとする曲線について、生成された２つの平面の両方における、円柱面の存在する側に存在する曲線の部分を投影可能な部分とし、生成された２つの平面のうちの少なくとも一方における、円柱面の存在しない側にある曲線の部分を投影可能でない部分として分割し、分割された投影可能な部分から両端点を含む幾つかの点を抽出し、抽出した各点から円柱面上に投影曲線を生成するので、投影可能な部分のみを投影することが可能になる。
また、請求項３記載の発明では、請求項２記載の発明において、曲線中に投影曲線が一意に定まらない部分を含むか否かを調べ、含まない場合のみ、投影曲線を求めるので、無駄な投影処理を途中までおこなってしまうというような事態を避けることができる。
また、請求項４記載の発明では、請求項３記載の発明において、円柱面の軸と曲線とが交差するか否かを調べ、交差する場合、その曲線は曲線中に投影曲線が一意に定まらない部分を含む曲線であるとして、投影曲線を求めないで処理を終了するので、円柱面の軸と曲線が交差する場合、無駄な投影処理を最初からおこなわないようにすることができる。
【０００９】
また、請求項５記載の発明では、請求項３記載の発明において、円柱面の軸と前記曲線とが重なる否かを調べ、重なる場合、その曲線は曲線中に投影曲線が一意に定まらない部分を含む曲線であるとして、投影曲線を求めないで処理を終了するので、円柱面の軸と曲線とが重なる場合、無駄な投影処理を最初からおこなわないようにすることができる。
また、請求項６記載の発明では、請求項２乃至請求項５のいずれか１項に記載の曲線投影方法における各工程を実行させるプログラムを情報処理装置上で実行させることができるので、情報処理装置を用いて請求項２乃至５のいずれか１項に記載の発明の効果を得ることができる。
また、請求項７記載の発明では、請求項６記載のプログラムをコンピュータ読取可能な記憶媒体に記憶することができるので、その記憶媒体をこれまで請求項２乃至請求項５のいずれか１項に記載の発明によった曲線投影をおこなえなかったパーソナルコンピュータなど情報処理装置に装着することにより、そのような情報処理装置においても請求項２乃至請求項５のいずれか１項に記載の発明の効果を得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施例を示す曲線投影方法の動作フロー図である。
【図２】本発明の一実施例を示す３次元形状処理装置の構成ブロック図である。
【図３】本発明の一実施例を示す曲線投影方法の説明図である。
【図４】本発明の一実施例を示す曲線投影方法の他の説明図である。
【図５】本発明の一実施例を示す曲線投影方法の他の説明図である。
【図６】本発明および従来技術の一例を示す曲線投影方法の説明図である。
【図７】本発明の一実施例を示す曲線投影方法の他の説明図である。
【図８】本発明の一実施例を示す曲線投影方法の他の説明図である。
【図９】従来技術の一例を示す曲線投影方法の説明図である。
【図１０】従来技術の一例を示す曲線投影方法の他の説明図である。
【図１１】従来技術の一例を示す曲線投影方法の他の説明図である。
【符号の説明】
１ システム制御部、２ ３次元形状処理部、３ 外部記憶装置、４ グラフィクス表示装置、５ プロッタ、６ 操作表示部、７ 通信制御部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to curve projection processing using a dedicated three-dimensional shape processing apparatus such as a CAD / CAM apparatus or a general-purpose information processing apparatus such as a personal computer, and in particular, a curve for projecting a curve in a normal direction onto a cylindrical surface. It relates to projection processing.
[0002]
[Prior art]
Conventionally, in a CAD / CAM device using a graphics display device and a computer, a curve above a three-dimensional solid curved surface is projected in a normal direction with respect to the curved surface by the following procedure. The three-dimensional solid refers to, for example, a shape generated as solid model data in a boundary representation format. The solid model in a boundary representation format is closed in a three-dimensional space by elements such as edges, vertices, and faces. This is a representation of a solid with a defined area.
(1) Several points including both end points are extracted from the curve, and a perpendicular line is drawn from each point on the curved surface (see FIG. 6).
(2) Smoothly connect the points on the curved surface of the perpendicular drawn on the curved surface to generate a curve (projection curve) that rides on the curved surface (see FIG. 9).
That is, a curved line is approximately projected by generating a curved line by connecting several projected points. However, in the above-described prior art, since points are extracted from the entire curve without considering whether the points can be projected on the curved surface, when points that cannot be projected are extracted, there are other points that can be projected. Even if it existed, the curve could not be projected onto the curved surface (see FIG. 10).
[0003]
As described above, in the conventional technique, when a point that cannot be projected is extracted, the curve cannot be projected onto a curved surface even if another point that can be projected exists. In addition, when the curve intersects or overlaps the magnetic domain of the cylindrical surface, the perpendicular drawn from the point extracted from such a place is not uniquely determined, so the projection curve to be obtained cannot be determined. It was not considered (see FIG. 11).
An object of the present invention is to solve such a problem of the prior art. Specifically, the curved surface to be projected is a cylindrical surface, and the central angle of the cylindrical surface is divided by two generatrices. A three-dimensional shape processing apparatus, a curve projection method, a program, and a storage medium capable of examining a projectable part on a curve and obtaining a projection curve for the projectable part when projecting to a section within 180 degrees Is to provide. Also, if the curve intersects or overlaps the axis of the cylinder surface, the perpendicular drawn from the point extracted from such a location is not uniquely determined, so the problem is that the projection curve to be obtained cannot be determined. Consider.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, in the first aspect of the present invention, in the three-dimensional shape processing apparatus you projected in the normal direction of the curve with respect to the cylindrical surface, be a boundary of one end of said cylindrical surface A central angle 180 delimited by a first generatrix that is a straight line parallel to the axis of the cylindrical surface and a second generatrix that is a boundary line at one other end and is a straight line parallel to the axis of the cylindrical surface . when projecting the curve against section within degrees, a first plane in which the first busbar and the shaft ride, the plane generating means for generating a second plane in which the second bus bar and the shaft ride For the curve to be projected, the portion of the curve existing on the side where the cylindrical surface exists in both of the two planes generated by the plane generating means is set as a projectable portion, and the two of the generated two planes At least one of the songs on the side where the cylindrical surface does not exist And the curve dividing means for dividing parts as parts not possible projection, the curve by dividing means including two end points from the divided projection moiety extracting several points, extracted projected from each point on the cylindrical surface Projection curve generating means for generating a curve.
Further, in the invention of claim 2, wherein, in the curve projection method in the three-dimensional shape processing apparatus which projects in the direction normal to the curve with respect to the cylindrical surface, of the circular cylindrical surface is the boundary of one end of said cylindrical surface A section within a central angle of 180 degrees divided by a first generatrix that is a straight line parallel to the axis and a second generatrix that is a boundary line at one end of the other and is a straight line parallel to the axis of the cylindrical surface against the time of projecting the curve, the first plane in which the first busbar and the shaft ride, the plane generation step of generating a second plane in which the second bus bar and the shaft ride, attempts projection As for the curve to be formed, the portion of the curve existing on the side where the cylindrical surface exists in both of the two planes generated in the plane generation step is set as a projectable part, and the curve in at least one of the two planes generated , The part of the curve on the side where the cylindrical surface does not exist A curve dividing step that divides the image as a non-projectable portion, and a number of points including both end points are extracted from the projectable portion divided in the curve dividing step, and a projection curve is formed on the cylindrical surface from each extracted point. And a projection curve generation step to be generated .
According to a third aspect of the present invention, in the curved line projection method according to the second aspect, whether or not a portion of the curved line that is not uniquely determined is included in the curved line, and a projected curved line is obtained only when the curved line is not included. I made it.
According to a fourth aspect of the present invention, in the curved line projection method according to the third aspect, it is checked whether or not the axis of the cylindrical surface and the curve intersect. Assuming that the curve includes a portion that is not uniquely determined, the process is terminated without obtaining a projection curve .
Further, in the invention according to claim 5, in the curve projection method according to claim 3, it is checked whether or not the axis of the cylindrical surface and the curve overlap, and in the case of overlap, the projection curve is uniquely determined in the curve. Assuming that the curve includes a non-existing portion, the processing is terminated without obtaining a projection curve.
According to a sixth aspect of the present invention, there is provided a program for causing a computer to execute each step in the curve projecting method according to any one of the second to fifth aspects.
The invention according to claim 7 is a computer-readable storage medium storing the program according to claim 6.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a block diagram showing the configuration of a three-dimensional shape processing apparatus showing an embodiment of the present invention. As shown in the figure, the three-dimensional shape processing apparatus of this embodiment includes a system control unit 1 that controls the entire apparatus, a three-dimensional shape processing unit that processes acquired three-dimensional shape data, such as a curve projection process according to the present invention. 2. External storage device (for example, hard disk device) for storing 3D shape data and programs. 3. Graphic display device 4 for displaying 3D shape according to 3D shape data. Output 3D shape on paper. A plotter 5, an operation display unit 6 having a keyboard, a mouse, a text display device, and the like, a communication control unit 7 for acquiring three-dimensional shape data from the outside via a network, and the like.
The system control unit 1 and the three-dimensional shape processing unit 2 have a memory (for example, a RAM) that temporarily stores a program according to the present invention and various data, and a CPU that operates according to the program. In this embodiment, the plane generating means, the curve dividing means, and the projection curve generating means described in claim 1 are realized by the three-dimensional shape processing unit 2.
With such a configuration, in the three-dimensional shape processing apparatus of this embodiment, the curve on the cylindrical surface constituting the three-dimensional solid shape is within a central angle of 180 degrees divided by the two buses of the cylindrical surface. When projecting to the section, a projectable part on the curve is examined, and a projection curve is obtained (generated) for the projectable part.
[0006]
FIG. 1 shows an operation flow of an embodiment of the present invention. The operation flow of this embodiment will be described below with reference to FIG.
First, the three-dimensional shape processing unit 2 creates a plane a as shown in FIG. 3 (S1). That is, a plane a on which an axis c of a cylindrical surface (concave curved surface in the illustrated example) and one generatrix of the cylindrical surface (a boundary line at one end of the cylindrical surface and a straight line parallel to the axis c) is created. (Refer to FIG. 3: a view seen from the axial direction of the cylindrical surface). Furthermore, the three-dimensional shape processing unit 2 also creates a plane b on which the other generatrix and the axis c of the cylindrical surface ride (see FIG. 3) (S2). Focusing on the generatrix on the plane, the side where the cylindrical surface exists is the back side of the plane, and the side where the cylindrical surface does not exist is the front side of the plane.
Subsequently, the three-dimensional shape processing unit 2 has a portion to be projected on the back side of either of the two planes (portion A shown in FIG. 4) and at least one of the curves to be projected. The curve is divided into a portion existing on the front side (portion B shown in FIG. 4) (S3). Note that the portion where the curve intersects the plane is considered to exist on the back side.
Thus, if the A part exists in the curve and the part does not intersect or overlap the axis of the cylinder, it is determined that the part can be projected (see FIG. 5) (in S4). Yes). The point where the curved line intersects the plane is an end that can be projected, but since a straight line extending from the point in the normal direction of the curved surface to the cylindrical surface is on the plane, the straight line And the point where the curved surface (cylindrical surface) intersects does not protrude from the curved surface. Note that if the curved line includes a portion where the projected curve that intersects or overlaps the axis of the cylinder is not uniquely determined, the operation flow is terminated without obtaining the projected curve.
Subsequently, the three-dimensional shape processing unit 2 extracts a number of points including both end points of the A portion that is regarded as projectable (S5), and creates a perpendicular line from the respective points on the cylindrical surface. Lower (see FIG. 6) (S6). Further, a plurality of perpendicular feet (points on the cylindrical surface of the perpendicular) drawn down on the curved surface are smoothly connected (S7), and a projection curve of the projectable portion is generated.
On the other hand, when it is determined in step S4 that there is no projectable portion (No in S4), this operation flow is terminated at that time.
In this way, according to this embodiment, it is possible to generate a projection curve only for a projectable portion, and therefore, it is possible to project another point because the perpendicular cannot be lowered from the point extracted on the curve to be projected. In spite of the existence, it is possible to solve the problem that any part of the curve cannot be projected onto the curved surface.
[0007]
As described above, the projection curve generation method of the present invention has been described with reference to the drawing of the concave curved cylindrical surface, but it can be similarly applied to the case of the convex curved cylindrical surface. FIG. 7 and FIG. 8 are explanatory diagrams in the case of a convex cylindrical surface. 7 corresponds to FIG. 3, and FIG. 8 corresponds to FIG.
Further, a program programmed according to the curve projection method as described above is stored in, for example, a removable storage medium, and the storage medium is mounted on an information processing apparatus such as a personal computer that has not been able to perform curve projection according to the present invention. Thus, or by transferring such a program to such an information processing apparatus via a network, the curve projection according to the present invention can be performed also in such an information processing apparatus.
[0008]
【The invention's effect】
As described above, according to the present invention, in the first aspect of the present invention, the first bus that is a boundary line at one end of the cylindrical surface and is a straight line parallel to the axis of the cylindrical surface , for one end of the boundary line and is the second bus and the separated central angle of 180 degrees within the interval of an axis and a straight line parallel to the circular cylindrical surface, when projecting the curve in the normal direction, the A first plane on which one bus and an axis ride and a second plane on which a second bus and an axis ride, and for a curve to be projected, the cylindrical surface in both of the two planes generated Divide the part of the curve that exists on the existing side as a projectable part, and divide the part of the curved line that does not exist on the cylindrical surface in at least one of the two generated planes as a non-projectable part. Several points including both end points from the projected part Since the points extracted can generate a projected curve on the cylindrical surface, when the part that can not be projected are extracted, to solve the problem of being unable projecting the curve even when there is a point that can be projected on other Can do.
In the invention according to claim 2 , the first bus line which is a boundary line at one end of the cylindrical surface and a straight line parallel to the axis of the cylindrical surface , and the boundary line at one other end of the cylindrical surface When a curve is projected in a normal direction with respect to a section within a central angle of 180 degrees divided by a second bus that is a straight line parallel to the axis of the surface , the first bus and the axis ride on the first A plane and a second plane on which the second generatrix and the axis ride are generated, and for the curve to be projected, a portion of the curve existing on the side where the cylindrical surface exists in both of the two generated planes Divide the portion of the curve on the side where the cylindrical surface does not exist in at least one of the two generated planes as a non-projectable portion, and set the end points from the divided projectable portions. Extract some points including it, and from each extracted point on the cylindrical surface Since generating a shadow curve, it is possible to project only the projection moiety.
Also, in the invention described in claim 3, in the invention of claim 2, checks whether the projected curve in curve including uniquely determined part, only if they do not contain, so obtaining a projection curve, waste It is possible to avoid a situation in which a simple projection process is performed halfway.
Further, in the invention described in claim 4, in the invention described in claim 3, it is checked whether or not the axis of the cylindrical surface and the curve intersect, and in the case of intersecting, the projection curve is uniquely determined in the curve. and that the curve containing the free portions, so the process ends without asking a projection curve, if the axis and the curve of the cylindrical surface intersects, it is possible not performed useless projection process from the beginning.
[0009]
Further, in the invention according to claim 5, in the invention according to claim 3, it is checked whether or not the axis of the cylindrical surface and the curve overlap, and in the case of overlapping, the curve is a portion where the projection curve is not uniquely determined in the curve. and that the curve containing, since the process ends without asking a projection curve, if the overlap with the shaft and the curve of the cylindrical surface, it is possible not performed useless projection process from the beginning.
In the invention according to claim 6 , since the program for executing each step in the curve projection method according to any one of claims 2 to 5 can be executed on the information processing apparatus, The effect of the invention according to any one of claims 2 to 5 can be obtained using an apparatus.
Further, the invention of claim 7, it is possible to store a sixth aspect of the program in a computer readable storage medium, to any one of claims 2 to 5 the storage medium far The effect of the invention according to any one of claims 2 to 5 is also provided in such an information processing apparatus by being mounted on an information processing apparatus such as a personal computer that has not been able to perform the curve projection according to the described invention. Can be obtained.
[Brief description of the drawings]
FIG. 1 is an operation flowchart of a curve projection method showing an embodiment of the present invention.
FIG. 2 is a configuration block diagram of a three-dimensional shape processing apparatus showing an embodiment of the present invention.
FIG. 3 is an explanatory diagram of a curve projection method showing an embodiment of the present invention.
FIG. 4 is another explanatory diagram of a curve projection method showing an embodiment of the present invention.
FIG. 5 is another explanatory diagram of a curve projection method showing an embodiment of the present invention.
FIG. 6 is an explanatory diagram of a curve projection method showing an example of the present invention and the prior art.
FIG. 7 is another explanatory diagram of a curve projection method showing an embodiment of the present invention.
FIG. 8 is another explanatory diagram of a curve projection method showing an embodiment of the present invention.
FIG. 9 is an explanatory diagram of a curve projection method showing an example of a conventional technique.
FIG. 10 is another explanatory diagram of a curve projection method showing an example of a conventional technique.
FIG. 11 is another explanatory diagram of a curve projection method showing an example of a conventional technique.
[Explanation of symbols]
1 system control unit, 2 3D shape processing unit, 3 external storage device, 4 graphics display device, 5 plotter, 6 operation display unit, 7 communication control unit

Claims (7)

曲線を円柱面に対して法線方向に投影する３次元形状処理装置において、前記円柱面の一方の一端の境界線であり該円柱面の軸と平行な直線である第１の母線と、他の一方の一端の境界線であり該円柱面の軸と平行な直線である第２の母線とによって区切られた中心角１８０度以内の区間に対して曲線を投影する際に、前記第１の母線と軸が乗る第１の平面と、前記第２の母線と軸が乗る第２の平面とを生成する平面生成手段と、投影しようとする曲線について、前記平面生成手段により生成された２つの平面の両方における、円柱面の存在する側に存在する曲線の部分を投影可能な部分とし、生成された２つの平面のうちの少なくとも一方における、円柱面の存在しない側にある曲線の部分を投影可能でない部分として分割する曲線分割手段と、前記曲線分割手段により分割された投影可能な部分から両端点を含む幾つかの点を抽出し、抽出した各点から円柱面上に投影曲線を生成する投影曲線生成手段と、を備えたことを特徴とする３次元形状処理装置。In the three-dimensional shape processing apparatus you projected in the normal direction of the curve with respect to the cylindrical surface, the first and the generating line is an axis and a straight line parallel on one circular cylindrical surface is the boundary of one end of said cylindrical surface, when projecting the curve to the other one of the end border in and of the circular cylindrical surface parallel to the axis linearly in a second bus and the separated central angle of 180 degrees within the interval of the first a first plane ride of the bus and the shaft, and the plane generating means for generating a second plane in which the second bus bar and the shaft ride, the curve to be projected, 2 generated by the plane generating means In both of the two planes, the portion of the curve existing on the side where the cylindrical surface exists is a projectable portion, and the portion of the curve on the side where the cylindrical surface does not exist in at least one of the two generated planes curve split hand to divide as part not possible projection When, with a projection curve generating means for generating a projected curve onto the cylindrical surface from each point extracting several points, and extracted inclusive points from the divided projection moiety by the curve dividing means A three-dimensional shape processing apparatus. 曲線を円柱面に対して法線方向に投影する３次元形状処理装置における曲線投影方法において、前記円柱面の一方の一端の境界線であり該円柱面の軸と平行な直線である第１の母線と、他の一方の一端の境界線であり該円柱面の軸と平行な直線である第２の母線とによって区切られた中心角１８０度以内の区間に対して曲線を投影する際に、前記第１の母線と軸が乗る第１の平面と、前記第２の母線と軸が乗る第２の平面とを生成する平面生成工程と、投影しようとする曲線について、前記平面生成工程で生成された２つの平面の両方における、円柱面の存在する側に存在する曲線の部分を投影可能な部分とし、生成された２つの平面のうちの少なくとも一方における、円柱面の存在しない側にある曲線の部分を投影可能でない部分として分割する曲線分割工程と、前記曲線分割工程で分割された投影可能な部分から両端点を含む幾つかの点を抽出し、抽出した各点から円柱面上に投影曲線を生成する投影曲線生成工程と、を有することを特徴とする曲線投影方法。In curve projection method in the three-dimensional shape processing apparatus which projects in the direction normal to the curve with respect to the cylindrical surface, a boundary of one end of the cylindrical surface of the circular cylindrical surface axis and the first is a line parallel and bus, when projecting the curve with respect to the second bus and the separated central angle of 180 degrees within the interval of an axis and a straight line parallel to and circular cylindrical surface a boundary of the other one end, a first plane in which the first busbar and the shaft ride, the plane generation step of generating a second plane in which the second bus bar and the shaft ride, the curve to be projected, generated in the plane generation step In both of the generated two planes, the portion of the curve existing on the side where the cylindrical surface exists is a projectable portion, and the curve on the side where the cylindrical surface does not exist in at least one of the two generated planes As a non-projectable part A curve dividing step for extracting, and a projection curve generating step for extracting several points including both end points from the projectable portion divided in the curve dividing step, and generating a projection curve on the cylindrical surface from each of the extracted points; , curve projection method characterized in that it comprises a. 請求項２記載の曲線投影方法において、前記曲線中に投影曲線が一意に定まらない部分を含むか否かを調べ、含まない場合のみ、投影曲線を求めることを特徴とする曲線投影方法。 3. The curve projecting method according to claim 2, wherein whether or not the projected curve includes a portion where the projected curve is not uniquely determined is checked in the curve, and the projected curve is obtained only when the portion is not included. 請求項３記載の曲線投影方法において、円柱面の軸と前記曲線とが交差するか否かを調べ、交差する場合、その曲線は曲線中に投影曲線が一意に定まらない部分を含む曲線であるとして、投影曲線を求めないで処理を終了することを特徴とする曲線投影方法。4. The curve projecting method according to claim 3, wherein whether or not the axis of the cylindrical surface and the curve intersect is checked, and if it intersects, the curve includes a portion in which the projection curve is not uniquely determined. As a curve projection method, the process is terminated without obtaining a projection curve. 請求項３記載の曲線投影方法において、円柱面の軸と前記曲線とが重なる否かを調べ、重なる場合、その曲線は曲線中に投影曲線が一意に定まらない部分を含む曲線であるとして、投影曲線を求めないで処理を終了することを特徴とする曲線投影方法。4. The method of projecting a curve according to claim 3, wherein whether or not the axis of the cylindrical surface and the curve overlap is examined, and if so, the curve is projected as a curve including a portion where the projection curve is not uniquely determined A curve projection method characterized in that the processing is terminated without obtaining a curve. コンピュータに請求項２乃至請求項５のいずれか１項に記載の曲線投影方法における各工程を実行させるためのプログラム。The program for making a computer perform each process in the curve projection method of any one of Claim 2 thru | or 5. 請求項６記載のプログラムを記憶したコンピュータ読取可能な記憶媒体。A computer-readable storage medium storing the program according to claim 6.
JP2003005033A 2003-01-10 2003-01-10 Three-dimensional shape processing apparatus, curve projection method, program, and storage medium Expired - Fee Related JP4160406B2 (en)

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