[vtkusers] Weird white edges while trying to convert point cloud to mesh

[Franse]

Hallo fellow VTK users,

Recently I've been trying to learn VTK and so far I'm quite satisfied with
it. But now I have encountered a problem I cannot fix on my own and need
some help to do so.

As you can see from the attached screenshot, there are weird white edges on
the triangulated point cloud. Where do they come from and how can I get rid
of them?

Altogether I want to convert a XYZ point cloud to a mesh and view, alter and
the mesh as an STL file. As far as I know, the result of a Delaunay3D filter
is a triangulated point cloud a.k.a. an unstructured grid. How can I get to
a mesh from there? I would like to fill the holes in there. I am still a
little bewildered by the conversions between different formats in VTK. There
is an abundance of options to go, but finding the right one can be hard.

Thanks in advance for your help!
Franz

http://vtk.1045678.n5.nabble.com/file/n4626151/white_edges.jpg 



My code so far looks like that:

#include <vtkSmartPointer.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkSimplePointsReader.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkProperty.h>
#include <vtkSTLWriter.h>
#include <vtkCleanPolyData.h>
#include <vtkDelaunay3D.h>
#include <vtkDataSetMapper.h>
#include <vtkFillHolesFilter.h>
#include <vtkWindowedSincPolyDataFilter.h>


int main(int argc, char* argv[])
{
  // verify argument 2: <exe> <xyz file>
  if ( argc != 2 )
    {
    std::cout << "Usage: " << argv[0]
              << " filename.asc" << std::endl;
    return EXIT_FAILURE;
    }
 
  // read the file
  vtkSmartPointer<vtkSimplePointsReader> reader =
    vtkSmartPointer<vtkSimplePointsReader>::New();
  reader->SetFileName(argv[1]);
  reader->Update();
   
  // visualization pipeline: mapper -> actor -> renderer
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(reader->GetOutputPort());
  mapper->ScalarVisibilityOff();
 
  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  //actor->GetProperty()->SetPointSize(1);//
  actor->GetProperty()->SetColor(1,0,0);
  
 // Clean the polydata. This will remove duplicate points that may be
  // present in the input data.
  vtkSmartPointer<vtkCleanPolyData> cleaner =
    vtkSmartPointer<vtkCleanPolyData>::New();
  cleaner->SetInputConnection (reader->GetOutputPort());
  cleaner->SetTolerance(0.006);//0.007
  cleaner->Update();

  // Generate a tetrahedral mesh from the input points. By
  // default, the generated volume is the convex hull of the points.
  vtkSmartPointer<vtkDelaunay3D> delaunay3D =
    vtkSmartPointer<vtkDelaunay3D>::New();
  delaunay3D->SetInputConnection (cleaner->GetOutputPort());
  delaunay3D->SetOffset(2.5);
  delaunay3D->SetAlpha(0.6);
  //delaunay3D->SetTolerance(0.001);
 
  /*vtkSmartPointer<vtkFillHolesFilter> fillHolesFilter =
    vtkSmartPointer<vtkFillHolesFilter>::New();
  fillHolesFilter->SetInputConnection(delaunay3D->GetOutputPort());
  //fillHolesFilter->set
  fillHolesFilter->Update();*/

  vtkSmartPointer<vtkDataSetMapper> delaunayMapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  delaunayMapper->SetInputConnection(delaunay3D->GetOutputPort());
 
  vtkSmartPointer<vtkActor> delaunayActor =
    vtkSmartPointer<vtkActor>::New();
  delaunayActor->SetMapper(delaunayMapper);
  delaunayActor->GetProperty()->SetInterpolationToPhong();
  delaunayActor->GetProperty()->ShadingOn();
 
  // Visualize
  vtkSmartPointer<vtkRenderer> delaunayRenderer =
    vtkSmartPointer<vtkRenderer>::New();
 
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(500,400);
 
  renderWindow->AddRenderer(delaunayRenderer);
 
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  delaunayRenderer->AddActor(delaunayActor);
  delaunayRenderer->SetBackground(0.5, 0.5, 0.9);

 
  // Render and interact
  renderWindow->Render();
  renderWindowInteractor->Start();
  return EXIT_SUCCESS;
}


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