Macro Section

(parametric!)

Section
Description
Alternative implementation of Part Section tool (parametric) This macro does the same by extracting the section edges from result of generalFuse (GFA). The result is C1-continuous and has less knots. It is still not terrific for sweeping, but much better than plain Part Section. Macro version: 1.1 Last modified: 2018-04-28 FreeCAD version: All Download: ToolBar Icon Author: DeepSOIC
Author
DeepSOIC
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Macro Version
1.1
Date last modified
2018-04-28
FreeCAD Version(s)
All
Default shortcut
None
See also
None

Part Section tool produces edges with C0 continuity and large number of segments (knots), which is not very suitable as Sweep path.

This macro does the same by extracting the section edges from result of generalFuse (GFA). The result is C1-continuous and has less knots. It is still not terrific for sweeping, but much better than plain Part Section.

Requires FreeCAD v0.17+ built against OCC no less than 6.9.0 (tested on 7.0.0).

Installation:

download the file and save it in macro directory:

https://github.com/DeepSOIC/FreeCAD-Macros/raw/master/Section/MacroSection.py

How to use:

1. Select two shapes to compute section between
2. In FreeCAD menu: Macro → Macros... → double-click MacroSection.py . A new object will be created.

After running the macro once, you can add a toolbar button. Go to Tools → Customize, Toolbars, pick MacroSection on left dropdown list, and add the command to any of your custom toolbars.

Script

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MacroSection.py

#***************************************************************************
#*                                                                         *
#*   Copyright (c) 2016 - Victor Titov (DeepSOIC)                          *
#*                                               <vv.titov@gmail.com>      *  
#*                                                                         *
#*   This program is free software; you can redistribute it and/or modify  *
#*   it under the terms of the GNU Lesser General Public License (LGPL)    *
#*   as published by the Free Software Foundation; either version 2 of     *
#*   the License, or (at your option) any later version.                   *
#*   for detail see the LICENCE text file.                                 *
#*                                                                         *
#*   This program is distributed in the hope that it will be useful,       *
#*   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
#*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
#*   GNU Library General Public License for more details.                  *
#*                                                                         *
#*   You should have received a copy of the GNU Library General Public     *
#*   License along with this program; if not, write to the Free Software   *
#*   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
#*   USA                                                                   *
#*                                                                         *
#***************************************************************************

__title__="Macro Section"
__author__ = "DeepSOIC"
__doc__ = '''
Macro Section.
Alternative implementation of Part Section tool.
Requires FreeCAD v0.17+ and OCC 6.9.0+

Instructions:
First of all, save this macro as MacroSection.py, into a location from where it can be imported. FC's standard macro location is the best place to do that.

Select two shapes to compute section between.
Then, in Py console:

import MacroSection
MacroSection.run()

OR

just run this file as a macro.

Parametric Section object is created.
'''
if __name__ == "__main__": #being run as a macro
    import MacroSection
    MacroSection.run()

import FreeCAD as App
if App.GuiUp:
    import FreeCADGui as Gui
import Part

def makeSectionFeature():
    '''makeSectionFeature(): makes a Section parametric feature object. Returns the new object.'''
    selfobj = App.ActiveDocument.addObject("Part::FeaturePython","Section")
    Section(selfobj)
    ViewProviderSection(selfobj.ViewObject)
    return selfobj

class Section:
    "The Section feature object"
    def __init__(self,selfobj):
        selfobj.addProperty("App::PropertyLink","Base","Section","Input shape")
        selfobj.addProperty("App::PropertyLink","Tool","Section","Input shape")
        selfobj.Proxy = self

    def execute(self,selfobj):
        import BOPTools
        import BOPTools.ShapeMerge
        from BOPTools.Utils import HashableShape
        
        if len(selfobj.Base.Shape.Faces) == 0 or len(selfobj.Tool.Shape.Faces) == 0:
            raise ValueError("Shapes must have at least one face each.")
        sh1 = Part.Compound(selfobj.Base.Shape.Faces)
        sh2 = Part.Compound(selfobj.Tool.Shape.Faces)
        pieces, map = sh1.generalFuse([sh2])
        pieces = pieces.childShapes()
        assert(len(pieces) == 2)
        
        edges1 = set([HashableShape(edge) for edge in pieces[0].Edges])
        edges2 = set([HashableShape(edge) for edge in pieces[1].Edges])
        edges_to_return = list(set.intersection(edges1, edges2))
        edges_to_return = [edge.Shape for edge in edges_to_return] #convert hashable shapes back to plain shapes
        print("returning {num} edges of total {tot}".format(num= len(edges_to_return), tot= len(edges1)+len(edges2)))
        
        selfobj.Shape = BOPTools.ShapeMerge.mergeWires(edges_to_return)

class ViewProviderSection:
    def __init__(self,vobj):
        vobj.Proxy = self
       
    def getIcon(self):
        return ":/icons/Part_Section.svg"

    def attach(self, vobj):
        self.ViewObject = vobj
        self.Object = vobj.Object
  
    def __getstate__(self):
        return None

    def __setstate__(self,state):
        return None

    def claimChildren(self):
        return [self.Object.Base, self.Object.Tool]
        
    def onDelete(self, feature, subelements): # subelements is a tuple of strings
        try:
            self.Object.Base.ViewObject.show()
            self.Object.Tool.ViewObject.show()
        except Exception as err:
            App.Console.PrintError("Error in onDelete: " + err.message)
        return True

class CommandMacroSection:
    "Command to create Section feature"
    def GetResources(self):
        return {'Pixmap'  : ":/icons/Part_Section.svg",
                'MenuText': "Section",
                'Accel': "",
                'ToolTip': "Macro_Section: alternative implementation of Part Section tool"}

    def Activated(self):
        run()
    def IsActive(self):
        if App.ActiveDocument:
            return True
        else:
            return False

if App.GuiUp:
    Gui.addCommand("Macro_Section", CommandMacroSection())

def run():
    sel = Gui.Selection.getSelectionEx()
    try:
        if len(sel) != 2:
            raise Exception("Select two shapes to compute section between, first! Then run this macro.")
        try:
            App.ActiveDocument.openTransaction("Macro Section")
            selfobj = makeSectionFeature()
            selfobj.Base = sel[0].Object
            selfobj.Tool = sel[1].Object
            selfobj.Base.ViewObject.hide()
            selfobj.Tool.ViewObject.hide()
            
            selfobj.Proxy.execute(selfobj)
        finally:
            App.ActiveDocument.commitTransaction()
    except Exception as err:
        from PySide import QtGui
        mb = QtGui.QMessageBox()
        mb.setIcon(mb.Icon.Warning)
        mb.setText(err.message)
        mb.setWindowTitle("Macro Section")
        mb.exec_()