Part Module/ja: Difference between revisions

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{{Docnav
{{docnav|[[OpenSCAD Module|OpenSCAD Module]]|[[PartDesign Workbench|PartDesign Workbench]]|IconL=OpenSCADWorkbench.svg|IconR=Workbench_PartDesign.svg}}
|[[OpenSCAD Module|OpenSCAD Module]]

|[[PartDesign Workbench|PartDesign Workbench]]
[[Image:Workbench_Part.svg|64px]]
|IconL=Workbench_OpenSCAD.svg
|IconR=Workbench_PartDesign.svg
}}


[[Image:Workbench_Part.svg|thumb|128px|Part workbench icon]]
{{TOCright}}
<div class="mw-translate-fuzzy">
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FreeCADのCAD機能は[http://en.wikipedia.org/wiki/Open_CASCADE 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。[[Mesh Module/jp|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。
FreeCADのCAD機能は[http://en.wikipedia.org/wiki/Open_CASCADE 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。[[Mesh Module/jp|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。
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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 modelling 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|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|feature editing]]), until the final object is obtained.
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|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|feature editing]]), until the final object is obtained.


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

{{TOCright}}
[[Image:Part example.jpg]]


[[Image:Part_Workbench_relationships.svg|600px]]
[[Image:Part_Workbench_relationships.svg|600px]]
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These are tools for creating primitive objects.
These are tools for creating primitive objects.


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


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


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


* [[Image:Part_CompOffsetTools.png|48px]] [[Part_CompOffsetTools|Offset tools]]:
* [[Image:Part_CompOffsetTools.png|48px]] [[Part_CompOffsetTools|Offset tools]]:
** [[Image:Part_Offset.png|32px]] [[Part_Offset|3D Offset]]: Constructs a parallel shape at a certain distance from original.
** [[Image:Part_Offset.svg|32px]] [[Part_Offset|3D Offset]]: Constructs a parallel shape at a certain distance from original.
** [[Image:Part_Offset2D.png|32px]] [[Part_Offset2D|2D Offset]]: Constructs a parallel wire at certain distance from original, or enlarges/shrinks a planar face. {{Version|0.17}}
** [[Image:Part_Offset2D.svg|32px]] [[Part_Offset2D|2D Offset]]: Constructs a parallel wire at certain distance from original, or enlarges/shrinks a planar face. {{Version|0.17}}


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


* [[Image:Part_ProjectionOnSurface.png|32px]] [[Part_ProjectionOnSurface|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. {{Version|0.19}}
* [[Image:Part_ProjectionOnSurface.png|32px]] [[Part_ProjectionOnSurface|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. {{Version|0.19}}


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


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


* [[Image:Part_CompJoinFeatures.png|48px]] [[Part CompJoinFeatures|Join features]]: smart booleans for walled objects (e.g., pipes) {{Version|0.16}}
* [[Image:Part_CompJoinFeatures.png|48px]] [[Part CompJoinFeatures|Join features]]: smart booleans for walled objects (e.g., pipes) {{Version|0.16}}
** [[Image:Part JoinConnect.png|32px]] [[Part_JoinConnect|Connect]]: Connects interiors of objects {{Version|0.16}}
** [[Image:Part_JoinConnect.svg|32px]] [[Part_JoinConnect|Connect]]: Connects interiors of objects {{Version|0.16}}
** [[Image:Part JoinEmbed.png|32px]] [[Part_JoinEmbed|Embed]]: Embeds a walled object into another walled object {{Version|0.16}}
** [[Image:Part_JoinEmbed.svg|32px]] [[Part_JoinEmbed|Embed]]: Embeds a walled object into another walled object {{Version|0.16}}
** [[Image:Part JoinCutout.png|32px]] [[Part_JoinCutout|Cutout]]: Creates a cutout in a wall of an object for another walled object {{Version|0.16}}
** [[Image:Part_JoinCutout.svg|32px]] [[Part_JoinCutout|Cutout]]: Creates a cutout in a wall of an object for another walled object {{Version|0.16}}


* [[Image:Part_CompSplittingTools.png|48px]] [[Part CompSplittingTools|Splitting tools]]: {{Version|0.17}}
* [[Image:Part_CompSplittingTools.png|48px]] [[Part CompSplittingTools|Splitting tools]]: {{Version|0.17}}
** [[Image:Part BooleanFragments.png|32px]] [[Part_BooleanFragments|Boolean fragments]]: makes all the pieces that can be obtained by Boolean operations between objects {{Version|0.17}}
** [[Image:Part_BooleanFragments.svg|32px]] [[Part_BooleanFragments|Boolean fragments]]: makes all the pieces that can be obtained by Boolean operations between objects {{Version|0.17}}
** [[Image:Part SliceApart.svg|32px]] [[Part_SliceApart|Slice a part]]: tool to split shapes by intersection with other shapes
** [[Image:Part SliceApart.svg|32px]] [[Part_SliceApart|Slice a part]]: tool to split shapes by intersection with other shapes
** [[Image:Part Slice.png|32px]] [[Part_Slice|Slice]]: Splits an object into pieces by intersections with another object {{Version|0.17}}
** [[Image:Part_Slice.svg|32px]] [[Part_Slice|Slice]]: Splits an object into pieces by intersections with another object {{Version|0.17}}
** [[Image:Part XOR.png|32px]] [[Part_XOR|XOR]]: removes space shared by even number of objects (symmetric version of [[Part_Cut|Cut]]) {{Version|0.17}}
** [[Image:Part_XOR.svg|32px]] [[Part_XOR|XOR]]: removes space shared by even number of objects (symmetric version of [[Part_Cut|Cut]]) {{Version|0.17}}


* [[Image:Part Defeaturing.svg|32px]] [[Part_Defeaturing|Defeaturing]]: {{Version|0.18}}
* [[Image:Part Defeaturing.svg|32px]] [[Part_Defeaturing|Defeaturing]]: {{Version|0.18}}
* [[Image:Part_Section.png|32px]] [[Part_Section|Section]]: Creates a section by intersecting an object with a section plane
* [[Image:Part_Section.svg|32px]] [[Part_Section|Section]]: Creates a section by intersecting an object with a section plane
* [[Image:Part_SectionCross.png|32px]] [[Part_SectionCross|Cross sections...]]:
* [[Image:Part_CrossSections.svg|32px]] [[Part_SectionCross|Cross sections...]]: Creates one or more cross-sections through a selected shape
* [[Image:Part Attachment.svg|32px]] [[Part Attachment|Attachment]]: attachment is a utility to attach an object to another one.
* [[Image:Part Attachment.svg|32px]] [[Part Attachment|Attachment]]: attachment is a utility to attach an object to another one.


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


A complete list of all primitives and shapes refer to the [http://www.opencascade.org/org/doc/ OCC documentation] (Alternative: [http://opencascade.sourcearchive.com/documentation/6.3.0.dfsg.1-1/classes.html 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.
A complete list of all primitives and shapes refer to the [http://www.opencascade.org/org/doc/ OCC documentation] (Alternative: [https://www.opencascade.com/doc/occt-7.4.0/refman/html/ 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 [https://www.opencascade.com/doc/occt-7.0.0/overview/html/occt_user_guides__modeling_data.html Modeling Data User's Guide].

<blockquote style="color: slategray">''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.''</blockquote>

<blockquote style="color: slategray">''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.'' - [https://www.opencascade.com/content/geometry-and-topology Source]</blockquote>

<hr />

<blockquote style="color: slategray">''Thus, Topology defines the relationship between simple geometric entities, which can be linked together to represent complex shapes.'' - [https://www.opencascade.com/doc/occt-7.0.0/overview/html/occt_user_guides__modeling_data.html Modeling Data User's Guide]</blockquote>

[[File:ClassTopoDS_Shape_inherit_graph.png]]

'''Note:''' Only 3 types of topological objects have geometric representations – vertex, edge, and face ([https://opencascade.blogspot.com/2009/02/topology-and-geometry-in-open-cascade.html 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.
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.
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.
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.

[[File:Part_TopoShape_relationships.svg|600px]]

{{Caption|The {{incode|Part::TopoShape}} class is the geometrical object that is seen on screen. Essentially all workbenches use these [[Part_TopoShape|TopoShapes]] internally to build and display edges, faces, and solids.}}


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The most basic object that can be created is a [[Part Feature|Part Feature]], which has a simple {{PropertyData|Placement}} property, and basic properties to define its color and appearance.
The most basic object that can be created is a [[Part Feature|Part Feature]], which has a simple {{PropertyData|Placement}} property, and basic properties to define its color and appearance.

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

=== Test script ===

Test the creation of [[Part_Primitives|Part Primitives]] with a script. {{Version|0.19}}

{{Code|code=
import parttests.part_test_objects as pto
pto.create_test_file("example_file")
}}

This script is located in the installation directory of the program, and can be examined to see how the basic primitives are built.
{{Code|code=
$INSTALL_DIR/Mod/Part/parttests/part_test_objects.py
}}


=== 例 ===
=== 例 ===
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e = s.Edges[0]
e = s.Edges[0]
c = e.Curve
c = e.Curve

{{Code|code=
{{Code|code=
import Part,PartGui
import Part,PartGui
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doc.recompute()
doc.recompute()
}}
}}

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

{{Code|code=
{{Code|code=
import Part,PartGui
import Part,PartGui
doc=App.newDocument()
doc=App.newDocument()
}}
}}

loads the Part module and creates a new document
loads the Part module and creates a new document

{{Code|code=
{{Code|code=
l=Part.LineSegment()
l=Part.LineSegment()
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l.EndPoint=(1.0,1.0,1.0)
l.EndPoint=(1.0,1.0,1.0)
}}
}}

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

{{Code|code=
{{Code|code=
doc.addObject("Part::Feature","Line").Shape=l.toShape()
doc.addObject("Part::Feature","Line").Shape=l.toShape()
}}
}}

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.
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.

{{Code|code=
{{Code|code=
doc.recompute()
doc.recompute()
}}
}}

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

{{Code|code=
import FreeCAD
import Part
DOC = FreeCAD.newDocument()

def mycreateLine(pt1, pt2, objName):
obj = DOC.addObject("Part::Line", objName)
obj.X1 = pt1[0]
obj.Y1 = pt1[2]
obj.Z1 = pt1[2]

obj.X2 = pt2[0]
obj.Y2 = pt2[1]
obj.Z2 = pt2[2]

DOC.recompute()
return obj

line = mycreateLine((0,0,0), (0,10,0), "LineName")

}}




A circle can be created in a similar way:
A circle can be created in a similar way:

{{Code|code=
{{Code|code=
import Part
import Part
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doc.recompute()
doc.recompute()
}}
}}

or using:

{{Code|code=
import FreeCAD
import Part
DOC = FreeCAD.newDocument()

def mycreateCircle(rad, objName):
obj = DOC.addObject("Part::Circle", objName)
obj.Radius = rad

DOC.recompute()
return obj

circle = mycreateCircle(5.0, "CircleName")

}}


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:
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:

{{Code|code=
{{Code|code=
s = f.Shape
s = f.Shape
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c = e.Curve
c = e.Curve
}}
}}

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。
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。


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{{Part Tools navi{{#translation:}}}}
{{Userdocnavi}}
{{Userdocnavi{{#translation:}}}}
[[Category:Part]]
[[Category:Workbenches]]
[[Category:Workbenches{{#translation:}}]]

Revision as of 09:44, 28 May 2020

Part workbench icon

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.

The Part Workbench is the basic layer that exposes the OCCT drawing functions to all workbenches in FreeCAD

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.

  • Box: Draws a box by specifying its dimensions
  • Cylinder: Draws a cylinder by specifying its dimensions
  • Sphere: Draws a sphere by specifying its dimensions
  • Cone: Draws a cone by specifying its dimensions
  • Torus: Draws a torus (ring) by specifying its dimensions
  • Primitives: A tool to add any of the defined geometric primitives.
  • 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.

  • Extrude: Extrudes planar faces of an object
  • Revolve: Creates a solid by revolving another object (not solid) around an axis
  • Mirror: Mirrors the selected object on a given mirror plane
  • Fillet: Fillets (rounds) edges of an object
  • Chamfer: Chamfers edges of an object
  • Ruled Surface:
  • Loft: Lofts from one profile to another
  • Sweep: Sweeps one or more profiles along a path
  • Thickness: Hollows out a solid, leaving openings next to select faces.
  • Boolean: Performs boolean operations on objects
  • Union: Fuses (unions) two objects
  • Common: Extracts the common (intersection) part of two objects
  • Cut: Cuts (subtracts) one object from another

Measure

File:Std Measure Menu.png Measure: Allows linear and angular measurement between points, edges, and faces.

Other tools

Preferences

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.

The Part::TopoShape class is the geometrical object that is seen on screen. Essentially all workbenches use these TopoShapes internally to build and display edges, faces, and solids.

スクリプト処理

See also: 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 データPlacement 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. introduced in version 0.19

import parttests.part_test_objects as pto
pto.create_test_file("example_file")

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

$INSTALL_DIR/Mod/Part/parttests/part_test_objects.py

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
import Part,PartGui 
doc=App.newDocument()  
l=Part.LineSegment()
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()

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

import Part,PartGui
doc=App.newDocument()

loads the Part module and creates a new document

l=Part.LineSegment()
l.StartPoint=(0.0,0.0,0.0)
l.EndPoint=(1.0,1.0,1.0)

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

doc.addObject("Part::Feature","Line").Shape=l.toShape()

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.

doc.recompute()

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:

import FreeCAD
import Part
DOC = FreeCAD.newDocument()

def mycreateLine(pt1, pt2, objName):
    obj = DOC.addObject("Part::Line", objName)
    obj.X1 = pt1[0]
    obj.Y1 = pt1[2]
    obj.Z1 = pt1[2]

    obj.X2 = pt2[0]
    obj.Y2 = pt2[1]
    obj.Z2 = pt2[2]

    DOC.recompute()
    return obj

line = mycreateLine((0,0,0), (0,10,0), "LineName")


A circle can be created in a similar way:

import Part
doc = App.activeDocument()
c = Part.Circle() 
c.Radius=10.0  
f = doc.addObject("Part::Feature", "Circle")
f.Shape = c.toShape()
doc.recompute()

or using:

import FreeCAD
import Part
DOC = FreeCAD.newDocument()

def mycreateCircle(rad, objName):
    obj = DOC.addObject("Part::Circle", objName)
    obj.Radius = rad

    DOC.recompute()
    return obj

circle = mycreateCircle(5.0, "CircleName")


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:

s = f.Shape
e = s.Edges[0]
c = e.Curve

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