How to create a mesh data from vtkPoints?

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In VTK, points are only 3D coordinates. They serve as a support for cells.
To have a valid point cloud, you need:

  • a vtkDataSet that support explicit points, here we will use a vtkPolyData
  • the vtkPoints containing the points, which you already have
  • the vtkCellArray containing the cells so you have a valid VTK data set

We can construct one like that:

   // vtk data set to fill
   vtkNew<vtkPolyData> myPolyData;

   // compute a vtkIdList that contains ids of each points
  vtkIdType numPoints = myVtkPoints->GetNumberOfPoints();
  vtkSmartPointer<vtkIdList> pointIds = vtkSmartPointer<vtkIdList>::New();
  pointIds->SetNumberOfIds(numPoints);
  for (vtkIdType i = 0; i < numPoints; ++i)
  {
    pointIds->SetId(i, i);
  }

   // create a vtkCellArray from this list
  vtkSmartPointer<vtkCellArray> polyPoint = vtkSmartPointer<vtkCellArray>::New();
  polyPoint->InsertNextCell(pointIds);

   // give the points and cells to the final poly data
  myPolyData->SetPoints(myVtkPoints);
  myPolyData->SetVerts(polyPoint);

In this code, I assume you have myVtkPoints that is the vtkPoints containing the positions of points in your point cloud

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