# PlateVibration

VTKExamples/Python/VisualizationAlgorithms/PlateVibration

### Description

The motion of a vibrating beam is shown. The original undeformed outline is shown as a wireframe.

### Code

PlateVibration.py

    # Translated from vib.tcl

    import vtk

    def main():
        file_name = get_program_parameters()

        colors = vtk.vtkNamedColors()
        # Set the background color and plate color. Match those in VTKTextbook.pdf.
        bkg = map(lambda x: x / 256.0, [65, 99, 149])
        bar = map(lambda x: x / 256.0, [255, 160, 140])
        colors.SetColor("BkgColor", *bkg)
        colors.SetColor("PlateColor", *bar)

        # Read a vtk file
        #
        plate = vtk.vtkPolyDataReader()
        plate.SetFileName(file_name)
        plate.Update()
        bounds = [0] * 6
        plate.GetOutput().GetBounds(bounds)
        plate.SetVectorsName("mode2")

        normals = vtk.vtkPolyDataNormals()
        normals.SetInputConnection(plate.GetOutputPort())
        warp = vtk.vtkWarpVector()
        warp.SetInputConnection(normals.GetOutputPort())
        warp.SetScaleFactor(0.5)
        color = vtk.vtkVectorDot()
        color.SetInputConnection(warp.GetOutputPort())
        plateMapper = vtk.vtkDataSetMapper()
        plateMapper.SetInputConnection(warp.GetOutputPort())
        plateActor = vtk.vtkActor()
        plateActor.SetMapper(plateMapper)
        plateActor.GetProperty().SetColor(
            colors.GetColor3d("PlateColor"))
        plateActor.RotateX(-90)

        # Create the outline.
        #
        outline = vtk.vtkOutlineFilter()
        outline.SetInputConnection(plate.GetOutputPort())
        spikeMapper = vtk.vtkPolyDataMapper()
        spikeMapper.SetInputConnection(outline.GetOutputPort())
        outlineActor = vtk.vtkActor()
        outlineActor.SetMapper(spikeMapper)
        outlineActor.RotateX(-90)
        outlineActor.GetProperty().SetColor(colors.GetColor3d("White"))

        # Create the RenderWindow, Renderer and both Actors
        #
        ren = vtk.vtkRenderer()
        renWin = vtk.vtkRenderWindow()
        renWin.AddRenderer(ren)

        iren = vtk.vtkRenderWindowInteractor()
        iren.SetRenderWindow(renWin)

        # Add the actors to the renderer, set the background and size
        #
        ren.AddActor(plateActor)
        ren.AddActor(outlineActor)
        renWin.SetSize(500, 500)

        # Render the image.
        renWin.Render()
        ren.SetBackground(colors.GetColor3d("BkgColor"))
        # This closely matches the original illustration.
        ren.GetActiveCamera().SetPosition(-3.7, 13, 15.5)
        ren.ResetCameraClippingRange()

        renWin.Render()

        iren.Start()

    def get_program_parameters():
        import argparse
        description = 'Produces figure 6-14(a) Beam displacement from the VTK Textbook.'
        epilogue = '''
            Produce figure 6–14(a) Beam displacement from the VTK Textbook..
       '''
        parser = argparse.ArgumentParser(description=description, epilog=epilogue)
        parser.add_argument('filename', help='plate.vtk.')
        args = parser.parse_args()
        return args.filename

    if __name__ == '__main__':
        main()