vtkCleanPolyData cleanFilter = new vtkCleanPolyData();
cleanFilter.SetInput(polyData);
cleanFilter.Update();
vtkTubeFilter tube = new vtkTubeFilter();
tube.SetVaryRadiusToVaryRadiusByAbsoluteScalar();
tube.SetInput(cleanFilter.GetOutput());
tube.SetNumberOfSides(20);
tube.CappingOn();
vtkPolyDataMapper mapper = new vtkPolyDataMapper();
mapper.SetInput(tube.GetOutput());
mapper.ScalarVisibilityOn();
mapper.SetScalarModeToUsePointFieldData();
mapper.SelectColorArray("colors");
vtkActor actor = new vtkActor();