[Pythonocc-users] Odd Wrapper Behavior

[Frank Conradie]

I was hoping someone could explain the following odd wrapper behavior: 
if I build a TopoDS_Face inside a Python function, then return it from 
the function, the returned face seems to be different/invalid in the 
calling scope.
Here is the output:

faceInsideFunction.IsNull: 0
<OCC.TopoDS.TopoDS_Face; proxy of <Swig Object of type 'TopoDS_Face *' 
at 0x01BE4640> >

returnedFace.IsNull: 1
<OCC.TopoDS.TopoDS_Face; proxy of <Swig Object of type 'TopoDS_Face *' 
at 0x01BDF7E0> >

And here is the code that generated this output:

from OCC import gp, BRepBuilderAPI, TopoDS

def MakeFace(pts):
    gpnts = [gp.gp_Pnt(x,y,z) for x,y,z in pts]
    n = len(gpnts)
    gpnts.append(gpnts[0])
    mkwire = BRepBuilderAPI.BRepBuilderAPI_MakeWire()
    for i in range(n):
        mkedge = BRepBuilderAPI.BRepBuilderAPI_MakeEdge(gpnts[i], 
gpnts[i+1])
        mkwire.Add(mkedge.Edge())
    mkface = BRepBuilderAPI.BRepBuilderAPI_MakeFace(mkwire.Wire())
    f = mkface.Face()
    print 'faceInsideFunction.IsNull:', f.IsNull()
    print f
    return f

def Test1():
    y = 0.000
    o = 0.000
    d = 0.100
    fpts = [
        [o,  y,o  ],
        [o+d,y,o  ],
        [o+d,y,o+d],
        [o,  y,o+d],
    ]
    f1 = MakeFace(fpts)
    print
    print 'returnedFace.IsNull:', f1.IsNull()
    print f1

if __name__ == '__main__':
    Test1()

Thanks for a great project!
Frank Conradie
Rossland, BC, Canada


_______________________________________________
Pythonocc-users mailing list
Pythonocc-users@gna.org
https://mail.gna.org/listinfo/pythonocc-users