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Description

Cette macro traduit le Placement d'un objet afin qu'un emplacement sélectionné devienne sa nouvelle origine. Cela peut être utile lorsque des objets importés à partir d'autres formats comme STL ou STEP sont mal situés pour être traités ultérieurement par FreeCAD.

Utilisation

1. Copiez la macro dans votre répertoire de macros. (Vous pouvez copier et coller dans l'éditeur de macros et enregistrer).
2. Sélectionnez d'abord, puis exécutez la macro. L'annulation est possible.

Les sélections suivantes sont prises en charge :

-- Single Vertex -- déplace vers l'origine

-- Single Line Segment -- point central déplacé vers l'origine

-- Single Circle or Circular Arc -- centre déplacé vers l'origine

-- Single Face -- C.G. déplacé vers l'origine

-- Single Object -- C.G. déplacé vers l'origine (supporte les Solid, Shell, Compound et CompSolid)

-- Three Vertices -- Centre du cercle en passant par les sommets déplacés vers l'origine (utile pour les cercles tessellés)

Macro MoveToOrigin.FCMacro

__Title__    = "MoveToOrigin"
__Author__   = "edwilliams16"
__Version__  = "00.02"
__Date__     = "2021.7.7"
debug = False
'''Usage:
This macro will adjust the placement of a shape to place a selected feature at the origin.
One vertex:  - to origin
One line segment - midpoint to origin
One circle - center to origin
One arc of circle - center to origin
One face - CG of face to origin
Three vertices - center of circle through vertices to origin
Shape - CG of shape to origin

If the shape is a BaseFeature inside a body, the base feature's placement in the body is adjusted.
'''
# Version 0.01  Original
# Version 0.02 - now handles objects in nested part containers

def circumcenter(A, B, C):
    '''Return the circumcenter of three 3D vertices'''
    a2 = (B - C).Length**2
    b2 = (C - A).Length**2
    c2 = (A - B).Length**2
    if a2 * b2 * c2 == 0.0:
        print('Three vertices must be distinct')
        return
    alpha = a2 * (b2 + c2 - a2)
    beta = b2 * (c2 + a2 - b2)
    gamma = c2 * (a2 + b2 - c2)
    return (alpha*A + beta * B + gamma * C)/(alpha + beta + gamma)

def centerofmass(subshapes):
    mass =0.0
    moment = App.Vector(0, 0, 0)
    for sh in subshapes:
        mass += sh.Volume
        moment += sh.Volume * sh.CenterOfMass
    return moment/mass  

def globalCG(obj, removeLocalOffset=True):
    '''Find COM of object in global coordinates
      remove local offset per https://forum.freecad.org/viewtopic.php?t=27821'''
    gpl = obj.getGlobalPlacement()
    pl = obj.Placement
    rpl= gpl.multiply(pl.inverse())
    if removeLocalOffset:
        return rpl.multVec(obj.Shape.CenterOfMass)
    else:
        return gpl.multVec(obj.Shape.CenterOfMass)



def globalGCGHierarchy(obj):
    ''' Compute global COM of an object hierarchy'''
    volume= 0
    moment = App.Vector(0., 0., 0.)
    def wrappedGCG(obj): 
        nonlocal volume, moment
        if hasattr(obj, 'Shape'):
            shape = obj.Shape
            if hasattr(shape, 'CenterOfMass'):
                print(f'{obj.Name}  {vectorRound(globalCG(obj, True), nDec)}')
                volume += shape.Volume
                moment += globalCG(obj, True).multiply(shape.Volume)
            else:
                for obj1 in obj.OutList:
                    if hasattr(obj1, 'Shape'):
                        wrappedGCG(obj1)
    wrappedGCG(obj)
    return (volume, moment)

def vectorRound(v, n):
    '''Round the output of App.Vector v to n dec places'''
    return App.Vector(round(v.x, n), round(v.y, n), round(v.z, n))
  
isGlobal = False
nDec = 3
selt = Gui.Selection.getSelectionEx()
if len(selt) != 1:
    print('Select one vertex, edge or object\nor three vertices for center of circle')
    shift = App.Vector(0, 0, 0)  # bail and do nothing  
else:
    sel = selt[0]
    if sel.HasSubObjects:
        vv = sel.SubObjects
        if len(vv) ==3 and vv[0].ShapeType == 'Vertex' and   vv[1].ShapeType == 'Vertex' and vv[2].ShapeType == 'Vertex':
            shift = circumcenter(vv[0].Point, vv[1].Point, vv[2].Point)
            if debug: print('Three Vertices')
        elif len(vv) == 1: 
            selected = sel.SubObjects[0]
            if selected.ShapeType == 'Vertex':
                shift = selected.Point
                if debug: print('One vertex')
            elif selected.ShapeType == 'Edge':
                if selected.Curve.TypeId == 'Part::GeomCircle':    #circles and arcs
                     shift = selected.Curve.Center
                     if debug: print('One arc')      
                elif selected.Curve.TypeId == 'Part::GeomLine':
                    shift = (selected.valueAt(selected.FirstParameter) + selected.valueAt(selected.LastParameter))/2 # mid-point
                    if debug: print('One line')
                else:
                    print(f'edge is {selected.Curve.TypeId} not handled')
                    shift = App.Vector(0, 0, 0)  # bail and do nothing
            elif selected.ShapeType == 'Face':
                shift = selected.CenterOfMass #center of face
                if debug: print('One face')
            else:
                print(f'ShapeType {selected.ShapeType} not handled')
                shift = App.Vector(0, 0, 0)  # bail and do nothing
        else:
            print('Wrong number of Selections')
            shift = App.Vector(0, 0, 0)  # bail and do nothing
    else:
        if debug: print(f'ObjectName is {sel.ObjectName}')
        #if sel.ObjectName[0:11] == 'BaseFeature':
        if hasattr(sel.Object, 'Shape'):
            if debug: print('One solid')
            shape = sel.Object.Shape
            if shape.ShapeType == 'Solid' or shape.ShapeType == 'Shell':
                shift = shape.CenterOfMass
            elif shape.ShapeType == 'Compound' or shape.ShapeType == 'CompSolid':
                #shift = centerofmass(shape.SubShapes)
                vol, mom = globalGCGHierarchy(sel.Object)
                shift = mom.multiply(1./vol)  # global!
                isGlobal = True
            #more cases?
            else:
                print(f'Object ShapeType {sel.Object.Shape.ShapeType} not handled')
                shift = App.Vector(0, 0, 0)  # bail and do nothing                
        else:
            print(f'{sel.ObjectName} is not a shape')
            shift = App.Vector(0, 0, 0)  # bail and do nothing
            


pl = App.ActiveDocument.getObject(sel.ObjectName).Placement
gpl = App.ActiveDocument.getObject(sel.ObjectName).getGlobalPlacement()
gplr = gpl.multiply(pl.inverse())
if isGlobal:
    shift = gplr.inverse().multVec(shift) # global shift in LCS
print(f'Shift = {vectorRound(shift,nDec)}')
locorigin = gplr.inverse().multVec(App.Vector(0., 0., 0.)) #global origin in LCS
App.ActiveDocument.openTransaction('Undo Move to Origin')
App.ActiveDocument.getObject(sel.ObjectName).Placement.move(locorigin-shift)
App.ActiveDocument.commitTransaction()
App.ActiveDocument.recompute()

Lien

La discussion sur le forum MoveToOrigin Macro