[vtkusers] vtkBooleanOperationPolyDataFilter including disconnected faces

[Cory Quammen]

Eric,

It would be great if you could convert your scripts to C++. That will
make it a bit faster for me to debug.

Thanks,
Cory

On Mon, Jan 23, 2012 at 2:01 PM, Fahlgren, Eric
<efahlgren at lifemodeler.com> wrote:
> Cory,
>
> Thanks, if there's anything I can do, just holler.  I'm building VTK off the git HEAD on Win 7 with MS VC++ 2010.  Should I convert my Python scripts to C++ so you can include them into the test suite?
>
> Eric
>
>
>> -----Original Message-----
>> From: Cory Quammen [mailto:cquammen at cs.unc.edu]
>> Sent: Monday, January 23, 2012 10:22 AM
>> To: Fahlgren, Eric
>> Cc: vtkusers at vtk.org
>> Subject: Re: [vtkusers] vtkBooleanOperationPolyDataFilter including
>> disconnected faces
>>
>> Hi Eric,
>>
>> I am one of the main contributors of the boolean operation filters. I will
>> take a look at this bug within the next couple days.
>>
>> Thanks,
>> Cory
>>
>> On Mon, Jan 23, 2012 at 12:59 PM, Fahlgren, Eric
>> <efahlgren at lifemodeler.com> wrote:
>> > Here's another shot of a similar configuration (I think I've moved the
>> spheres from the previous example).  This one clearly shows the odd
>> shading on the stitching, which look to me to be normals pointed off to
>> Mars or possibly Alpha Centauri.  Could they just be pointed 180 off, an
>> inside/outside detection problem when generating those new faces that glue
>> the surfaces together?
>> >
>> > http://www.lifemodeler.com/eric/badNormals.png
>> >
>> > Eric
>> >
>> >>
>> >> Two problems, possibly related:
>> >>
>> >> 1) When I perform two successive Boolean operations, extraneous faces
>> >> from the second solid of the final operation are left in the polydata.
>> >>
>> >> 2) Note the faces in the red box of the linked image.  The normals
>> >> appear to be incorrect, there are occasional dark regions in odd
>> >> places on the resulting polydata.
>> >>
>> >> Is there a filter I can add after the Boolean operations to eliminate
>> >> the extra faces?  How about straightening up the normals?
>> >>
>> >> Thanks,
>> >> Eric
>> >>
>> >> #!/usr/bin/env python
>> >>
>> >> import vtk
>> >>
>> >> LHS = vtk.vtkCubeSource()
>> >> LHS.SetCenter((0.0, 0.0, 0.8))
>> >>
>> >> if 1:
>> >>    triangle = vtk.vtkTriangleFilter()
>> >>    triangle.SetInputConnection(LHS.GetOutputPort())
>> >>    LHS = triangle
>> >>
>> >> if 1:
>> >>    RHS = vtk.vtkSphereSource()
>> >>    RHS.SetCenter((0.5, 0.0, 0.2))
>> >>    RHS.SetRadius(1.0); RHS.SetPhiResolution(40);
>> >> RHS.SetThetaResolution(40)
>> >>
>> >>    boolOp = vtk.vtkBooleanOperationPolyDataFilter()
>> >>    boolOp.SetOperation(vtk.VTK_DIFFERENCE)
>> >>    boolOp.SetInputConnection(0, LHS.GetOutputPort())
>> >>    boolOp.SetInputConnection(1, RHS.GetOutputPort())
>> >>    LHS = boolOp
>> >>
>> >> if 1:
>> >>    RHS = vtk.vtkSphereSource()
>> >>    RHS.SetCenter((-0.5, 0.0, 0.3))
>> >>    RHS.SetRadius(1.0); RHS.SetPhiResolution(40);
>> >> RHS.SetThetaResolution(40)
>> >>
>> >>    boolOp = vtk.vtkBooleanOperationPolyDataFilter()
>> >>    boolOp.SetOperation(vtk.VTK_DIFFERENCE)
>> >>    boolOp.SetInputConnection(0, LHS.GetOutputPort())
>> >>    boolOp.SetInputConnection(1, RHS.GetOutputPort())
>> >>    LHS = boolOp
>> >>
>> >> if 0:
>> >>    fill = vtk.vtkFillHolesFilter()
>> >>   #fill.SetHoleSize(1.0)
>> >>    fill.SetInputConnection(LHS.GetOutputPort())
>> >>    LHS = fill
>> >>
>> >> mapper = vtk.vtkPolyDataMapper()
>> >> mapper.SetInputConnection(LHS.GetOutputPort(0))
>> >> mapper.ScalarVisibilityOff()
>> >>
>> >> actor = vtk.vtkActor()
>> >> actor.SetMapper(mapper)
>> >>
>> >> renderer = vtk.vtkRenderer()
>> >> renderWindow = vtk.vtkRenderWindow()
>> >> renderWindow.AddRenderer(renderer)
>> >> renderWindow.SetSize(1024, 1024)
>> >>
>> >> renderer.AddActor(actor)
>> >>
>> >> interactor = vtk.vtkRenderWindowInteractor()
>> >> interactor.SetRenderWindow(renderWindow)
>> >> interactor.Initialize()
>> >> renderWindow.Render()
>> >> interactor.Start()
>> >
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>>
>>
>>
>> --
>> Cory Quammen
>> Research Associate
>> Department of Computer Science
>> The University of North Carolina at Chapel Hill
>
>



-- 
Cory Quammen
Research Associate
Department of Computer Science
The University of North Carolina at Chapel Hill