# AppendFilter

VTKExamples/Python/Filtering/AppendFilter

This example loads points into a polydata and an unstructured grid then combines them. The example should be extended to show cells being combined as well.

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See (Cxx)

### Code

AppendFilter.py

    #!/usr/bin/env python

    import vtk

    def main():
        # Create 5 points (vtkPolyData)
        pointSource = vtk.vtkPointSource()
        pointSource.SetNumberOfPoints(5)
        pointSource.Update()

        polydata = pointSource.GetOutput()

        print "points in polydata are",polydata.GetNumberOfPoints()

        # Create 2 points in a vtkUnstructuredGrid
        points = vtk.vtkPoints()
        points.InsertNextPoint(0,0,0)
        points.InsertNextPoint(0,0,1)

        ug = vtk.vtkUnstructuredGrid()
        ug.SetPoints(points)
        print "points in unstructured grid are",ug.GetNumberOfPoints()

        # Combine the two data sets
        appendFilter = vtk.vtkAppendFilter()
        appendFilter.AddInputData(polydata)
        appendFilter.AddInputData(ug)
        appendFilter.Update()

        combined = vtk.vtkUnstructuredGrid()

        combined = appendFilter.GetOutput()
        print "Combined points are", combined.GetNumberOfPoints()

        # Create a mapper and actor
        colors = vtk.vtkNamedColors()

        mapper = vtk.vtkDataSetMapper()
        mapper.SetInputConnection(appendFilter.GetOutputPort())

        actor = vtk.vtkActor()
        actor.SetMapper(mapper)
        actor.GetProperty().SetPointSize(5)

        # Create a renderer, render window, and interactor
        renderer = vtk.vtkRenderer()
        renderWindow = vtk.vtkRenderWindow()
        renderWindow.AddRenderer(renderer)
        renderWindowInteractor = vtk.vtkRenderWindowInteractor()
        renderWindowInteractor.SetRenderWindow(renderWindow)

        # Add the actor to the scene
        renderer.AddActor(actor)
        renderer.SetBackground(colors.GetColor3d("SlateGray"))

        # Render and interact
        renderWindow.Render()
        renderWindowInteractor.Start()

    if __name__ == '__main__':
        main()