Part Module/ja



FreeCADのCAD機能はOpenCasCadeカーネルをその基礎としています. FreeCADはパートモジュールによってOpenCasCadeオブジェクトとその機能へのアクセス・利用を行なっています. OpenCascadeはプロフェッショナル用のCADカーネルでその機能は3D形状操作、3D形状オブジェクトに特化しています. メッシュモジュール のオブジェクトと異なりパートオブジェクトはより複雑で、明確なブーリアン演算、変更履歴、パラメトリックな動作などのより高度な処理が可能です.

The objects created with the Part Workbench are relatively simple; they are intended to be used with boolean operations (unions and cuts) in order to build more complex shapes. This modeling paradigm is known as the constructive solid geometry (CSG) workflow, and it was the traditional methodology used in early CAD systems. On the other hand, the PartDesign Workbench provides a more modern workflow to constructing shapes: it uses a parametrically defined sketch, that is extruded to form a basic solid body, which is then modified by parametric transformations (feature editing), until the final object is obtained.

Part objects are more complex than mesh objects created with the Mesh Workbench, as they permit more advanced operations like coherent boolean operations, modifications history, and parametric behaviour.



ツール
パートモジュールツールは全てパートモジュールを読み込んだ時点で表示されるPartメニューにあります.

Primitives
These are tools for creating primitive objects.


 * [[Image:Part_Box.svg|32px]] Box: Draws a box by specifying its dimensions
 * [[Image:Part_Cylinder.svg|32px]] Cylinder: Draws a cylinder by specifying its dimensions
 * [[Image:Part_Sphere.svg|32px]] Sphere: Draws a sphere by specifying its dimensions
 * [[Image:Part_Cone.svg|32px]] Cone: Draws a cone by specifying its dimensions
 * [[Image:Part_Torus.svg|32px]] Torus: Draws a torus (ring) by specifying its dimensions
 * [[Image:Part_Primitives.svg|32px]] Primitives: A tool to add any of the defined geometric primitives.
 * [[Image:Part_Shapebuilder.svg|32px]] Shapebuilder: A tool to create more complex shapes from various parametric geometric primitives

Modifying objects
These are tools for modifying existing objects. They will allow you to choose which object to modify.


 * [[Image:Part_Extrude.svg|32px]] Extrude: Extrudes planar faces of an object
 * [[Image:Part_Revolve.svg|32px]] Revolve: Creates a solid by revolving another object (not solid) around an axis
 * [[Image:Part_Mirror.svg|32px]] Mirror: Mirrors the selected object on a given mirror plane
 * [[Image:Part_Fillet.svg|32px]] Fillet: Fillets (rounds) edges of an object
 * [[Image:Part_Chamfer.svg|32px]] Chamfer: Chamfers edges of an object
 * [[Image:Part_RuledSurface.svg|32px]] Ruled Surface:
 * [[Image:Part_Loft.svg|32px]] Loft: Lofts from one profile to another
 * [[Image:Part_Sweep.svg|32px]] Sweep: Sweeps one or more profiles along a path


 * [[Image:Part_CompOffsetTools.png|48px]] Offset tools:
 * [[Image:Part_Offset.svg|32px]] 3D Offset: Constructs a parallel shape at a certain distance from original.
 * [[Image:Part_Offset2D.svg|32px]] 2D Offset: Constructs a parallel wire at certain distance from original, or enlarges/shrinks a planar face.


 * [[Image:Part_Thickness.svg|32px]] Thickness: Hollows out a solid, leaving openings next to select faces.


 * [[Image:Part_ProjectionOnSurface.png|32px]] Projection on surface: Project a logo, text or any face,wire,edge to a surface. With the projection part it is possible to create a solid or wire.


 * [[Image:Part_Compound.svg|48px]] Compound Tools:
 * [[Image:Part_Compound.svg|32px]] Make compound: Creates a compound from the selected objects.
 * [[Image:Part_ExplodeCompound.svg|32px]] Explode Compound: Tool to split up compounds of shapes
 * [[Image:Part Compound‏‎Filter.svg|32px]] Compound Filter: The CompoundFilter can be used to extract the individual pieces.


 * [[Image:Part_Booleans.svg|32px]] Boolean: Performs boolean operations on objects
 * [[Image:Part_Fuse.svg|32px]] Union: Fuses (unions) two objects
 * [[Image:Part_Common.svg|32px]] Common: Extracts the common (intersection) part of two objects
 * [[Image:Part_Cut.svg|32px]] Cut: Cuts (subtracts) one object from another


 * [[Image:Part_CompJoinFeatures.png|48px]] Join features: smart booleans for walled objects (e.g., pipes)
 * [[Image:Part_JoinConnect.svg|32px]] Connect: Connects interiors of objects
 * [[Image:Part_JoinEmbed.svg|32px]] Embed: Embeds a walled object into another walled object
 * [[Image:Part_JoinCutout.svg|32px]] Cutout: Creates a cutout in a wall of an object for another walled object


 * [[Image:Part_CompSplittingTools.png|48px]] Splitting tools:
 * [[Image:Part_BooleanFragments.svg|32px]] Boolean fragments: makes all the pieces that can be obtained by Boolean operations between objects
 * [[Image:Part SliceApart.svg|32px]] Slice a part: tool to split shapes by intersection with other shapes
 * [[Image:Part_Slice.svg|32px]] Slice: Splits an object into pieces by intersections with another object
 * [[Image:Part_XOR.svg|32px]] XOR: removes space shared by even number of objects (symmetric version of Cut)


 * [[Image:Part Defeaturing.svg|32px]] Defeaturing:
 * [[Image:Part_Section.svg|32px]] Section: Creates a section by intersecting an object with a section plane
 * [[Image:Part_CrossSections.svg|32px]] Cross sections...: Creates one or more cross-sections through a selected shape
 * [[Image:Part Attachment.svg|32px]] Attachment: attachment is a utility to attach an object to another one.

Measure
Measure: Allows linear and angular measurement between points, edges, and faces.


 * [[Image:Part_Measure_Linear.svg|32px]] Measure Linear allows you to make linear measurements.
 * [[Image:Part_Measure_Angular.svg|32px]] Measure Angular allows you to make angular measurements.
 * [[Image:Part_Measure_Refresh.svg|32px]] Measure Refresh updates the measurements on screen.
 * [[Image:Part_Measure_Clear_All.svg|32px]] Clear All Clears all measurements.
 * [[Image:Part_Measure_Toggle_All.svg|32px]] Toggle All shows or hides all measurements.
 * [[Image:Part_Measure_Toggle_3d.svg|32px]] Toggle 3D shows or hides 3D measurements.
 * [[Image:Part_Measure_Toggle_Delta.svg|32px]] Toggle Delta shows or hides delta measurements.

Other tools

 * [[Image:Part_Import.svg|32px]] Import: This tool allows you to add a file *.IGES, *.STEP, *.BREP to the current document.
 * [[Image:Part_Export.svg|32px]] Export: This tool allows you to export a part object in a *.IGES, *.STEP, *.BREP file.
 * Part_BoxSelection.svg BoxSelection: add to the selection the faces of the shapes that are touches by the rectangular selection.
 * [[Image:Part_ShapeFromMesh.svg|32px]] Shape from Mesh: Creates a shape object from a mesh object.
 * Part_PointsFromMesh.svg Points from mesh: creates a shape object made of points from the mesh.
 * Convert to solid: Converts a shape object to a solid object.
 * Reverse shapes: Flips the normals of all faces of the selected object.


 * Create a copy:
 * [[Image:Part_SimpleCopy‎.svg|32px]] Create simple copy: Creates a simple copy of the selected object.
 * Part_TransformedCopy.svg Create transformed copy: creates a transformed copy of the selected object.
 * Part_ElementCopy.svg Create shape element copy: creates a copy from an element (vertex, edge, face) of the selected object.
 * [[Image:Part_RefineShape.svg|32px]] Refine shape: Cleans faces by removing unnecessary lines.


 * [[Image:Part_CheckGeometry.svg|32px]] Check geometry: Checks the geometry of selected objects for errors.

Contextual Menu items

 * Appearance: determines appearance of the whole part (color transparency etc.).
 * Set colors: assigns colors to part faces.

Preferences

 * [[Image:Preferences-part_design.svg|32px]] Preferences: preferences available for Part Tools (the Part workbench also uses the PartDesign Preferences).
 * [[Image:Preferences-import-export.svg|32px]] Import Export Preferences: preferences available for importing from and exporting to different file formats.
 * Fine-tuning: some extra parameters to fine-tune Part behavior.

概念の説明
OpenCasCadeにおける用語では幾何プリミティブと（位相）シェイプは明確に区別されます. 幾何プリミティブとは点、ライン、円、平面、それにB-スプライン曲線や曲面などのより複雑なタイプのものです. シェイプは頂点、エッジ、ワイヤー、面、ソリッド、それに他のシェイプの合成物です. 幾何プリミティブは3Dシーン上に直接表示されることはありませんがシェイプの形状を作成するためには重要な役割を果たします. 例えばエッジははラインまたは円の一部から作成されます.

つまり幾何プリミティブとは"形のない"構成単位であり、シェイプはその上に作られた実際の空間的な形状であると言えるでしょう.

その完全なリストを入手したい場合はOCCドキュメント（あるいはsourcearchive.com）を参照し、 Geom_*（幾何プリミティブの場合）とTopoDS_*（シェイプの場合）を検索してください. 幾何オブジェクトとシェイプの違いについてより詳しい説明を読むことができます. 残念なことに公式のOCCドキュメントはオンラインで利用することができず（アーカイブをダウンロードしなければなりません）、またそのほとんどがプログラマー向けのものでエンドユーザーに向けたものではないことに注意してください. ただしこれから始めるために必要な情報についてはここで十分確認することができるはずです.

実のところ幾何オブジェクトは大きく二つに分けることができます. カーブとサーフェスです. カーブ（ライン、円・・・）からはエッジを直接的に作成でき、サーフェス（平面、円筒・・・）からはフェイスを作成できます. 例えば幾何プリミティブのラインは無限の長さを持ちます. つまり基底ベクトルと方向ベクトルによって定義されているのです. しかしそのシェイプ表現は始点と終点によって長さを制限されなければなりません. 同様に直方体 -- ソリッド -- は六つの制限つき平面によって作成されます.

エッジやフェイスからはその対となる幾何プリミティブに戻ることもできます.

このようにしてシェイプから非常に複雑なパーツを作成したり、逆に複雑なシェイプからそれを構成するサブシェイプを全て抜き出したりすることが可能になっているのです.

In summary, geometry primitives are "shapeless" building blocks, while topological shapes are the real objects built on them.

A complete list of all primitives and shapes refer to the OCC documentation (Alternative: sourcearchive.com) and search for Geom_* (for geometric primitives) and TopoDS_* (for shapes). There you can also read more about the differences between them. Please note that the official OCC documentation is not available online (you must download an archive) and is mostly aimed at programmers, not at end-users. But hopefully you'll find enough information to get started here. Also see Modeling Data User's Guide.

''At a very high level, topology tells what pieces an object is made of, and the logical relationships between them. A shape is made of a certain set of faces. A face is bounded by a certain set of edges. Two faces are adjacent if they share a common edge.''

''Topology alone does not tell you the size, curvature, or 3D locations of any of those pieces. However, each piece of topology does knows about it's underlying geometry. A face knows what surface it lies on. An edge knows what curve it lies on. The geometry knows about curvature and location in space.'' - Source

Thus, Topology defines the relationship between simple geometric entities, which can be linked together to represent complex shapes. - Modeling Data User's Guide



Note: Only 3 types of topological objects have geometric representations – vertex, edge, and face (Source).

The geometric types actually can be divided into two major groups: curves and surfaces. Out of the curves (line, circle, ...) you can directly build an edge, out of the surfaces (plane, cylinder, ...) a face can be built. For example, the geometric primitive line is unlimited, i.e. it is defined by a base vector and a direction vector while its shape representation must be something limited by a start and end point. And a box -- a solid -- can be created by six limited planes.

From an edge or face you can also go back to its geometric primitive counterpart.

Thus, out of shapes you can build very complex parts or, the other way round, extract all sub-shapes a more complex shape is made of.



スクリプト処理
Part scripting

パートモジュールで使用されている主なデータ構造はOpenCascadeのBRep（境界表現）データ型です. 現在ではパートモジュールのほとんど全ての機能とオブジェクト型がPythonスクリプトから利用可能になっています. これにはLineやCircle（あるいはArc）などの幾何プリミティブとVertexes、Edges、Wires、Faces、SolidsそしてCompoundsなどTopoShapesの全てが含まれます. これらの各オブジェクトにはいくつかの異なる作成方法があり、またオブジェクトの一部、特にTopoShapesではブーリアン演算の和集合/差集合/共通集合といったより高度な操作が可能になっています. パートモジュールの機能の詳細についてはFreeCADスクリプト処理の基礎ページを調べてください.

The most basic object that can be created is a Part Feature, which has a simple property, and basic properties to define its color and appearance.

Another simple object used in 2D geometrical objects is Part Part2DObject, which is the base of Sketcher SketchObject (Sketcher), and most Draft elements.

Test script
Test the creation of Part Primitives with a script.

This script is located in the installation directory of the program, and can be examined to see how the basic primitives are built.

例
ライン要素を作成するにはPythonコンソールを開き、以下のように入力します： import Part,PartGui doc=App.newDocument l=Part.Line l.StartPoint=(0.0,0.0,0.0) l.EndPoint=(1.0,1.0,1.0) doc.addObject("Part::Feature","Line").Shape=l.toShape doc.recompute

上記のPythonスクリプトの例をステップごとに見ていきましょう： import Part,PartGui doc=App.newDocument パートモジュールを読み込み、新しいドキュメントを作成します. l=Part.Line l.StartPoint=(0.0,0.0,0.0) l.EndPoint=(1.0,1.0,1.0) ラインは実際は線分なので始点と終点があります. doc.addObject("Part::Feature","Line").Shape=l.toShape Partオブジェクト型をドキュメントに追加し、追加したオブジェクトの'Shape'プロパティに線分のシェイプ表現を代入します. ここで理解すべき重要な点は幾何プリミティブ（Part.Line）を使ってそこから位相シェイプを作成した（toShapeメソッド）ということです. ドキュメントに追加できるのはシェイプだけです. FreeCADでは幾何プリミティブはシェイプのための"作成用構造体"として使用されます. doc.recompute ドキュメントを更新します. 新しいパートオブジェクトの視覚的な表現を用意するための処理でもあります.

LineはPart.Line(point1,point2)という風にその始点と終点をコンストラクタで直接指定して作成することもできますし、ここで行ったようにデフォルトのラインを作成してあとでそのプロパティを設定することもできるということを憶えておいてください.

同じようにして円を作ることもできます： import Part doc = App.activeDocument c = Part.Circle c.Radius=10.0 f = doc.addObject("Part::Feature", "Circle") f.Shape = c.toShape doc.recompute 先ほどと同様、円（幾何プリミティブ）を使ってそのシェイプを作成しました. もちろんこの後、下記のような方法で作成した形状にアクセスすることができます： s = f.Shape e = s.Edges[0] c = e.Curve

Let's go through the above python example step by step:

loads the Part module and creates a new document

Line is actually a line segment, hence the start and endpoint.

This adds a Part object type to the document and assigns the shape representation of the line segment to the 'Shape' property of the added object. It is important to understand here that we used a geometric primitive (the Part.LineSegment) to create a TopoShape out of it (the toShape method). Only Shapes can be added to the document. In FreeCAD, geometry primitives are used as "building structures" for Shapes.

Updates the document. This also prepares the visual representation of the new part object.

Note that a Line Segment can be created by specifying its start and endpoint directly in the constructor, for example Part.LineSegment(point1,point2), or we can create a default line and set its properties afterwards, as we did here.

A Line can be created also using:

A circle can be created in a similar way:

or using:

Note again, we used the circle (geometry primitive) to construct a shape out of it. We can of course still access our construction geometry afterwards, by doing:

ここではオブジェクトfのシェイプを取得した後、そのエッジのリストを取得しています. 今回の場合、エッジは一つしかありません. 円一つからシェイプ全体を作成しているためです. 従ってEdgesリストの最初のアイテムだけ取得し、その後でそのCurve（曲線）を取得しています. Edgeは全てCurveを持ちます. これはエッジの元になっている幾何プリミティブです.

さらに詳しく知りたい場合は位相データのスクリプト処理ページを見て下さい.

チュートリアル

 * Import from STL or OBJ : How to import STL/OBJ files in FreeCAD
 * Export to STL or OBJ : How to export STL/OBJ files from FreeCAD
 * Whiffle Ball tutorial : How to use the Part Module