Part Module/zh

Introduction
The solid modelling capabilities of FreeCAD are based on the OpenCASCADE Technology (OCCT) kernel, a professional-grade CAD system that features advanced 3D geometry creation and manipulation. The Part Workbench is a layer sitting on top of the OCCT libraries, that gives the user access to OCCT geometric primitives and functions. Essentially all 2D and 3D drawing functions in every workbench ( Draft, Sketcher,  PartDesign, etc.), are based on these functions exposed by the Part Workbench. Therefore, the Part Workbench is considered the core component of the modelling capabilities of FreeCAD.

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.



Tools
The tools are all located in the menu.

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
 * Part_Tube.svg Tube: draws a tube by specifying its internal radius and external radius.
 * [[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.

Context 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.

Scripting
See Part scripting.

Tutorials

 * 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