# WriteTriangleToFile

VTKExamples/Python/IO/WriteTriangleToFile

### Code

WriteTriangleToFile.py

    import vtk

    def get_program_parameters():
        import argparse
        description = 'Generate image data, then write a .stl file.'
        epilogue = '''
       '''
        parser = argparse.ArgumentParser(description=description, epilog=epilogue)
        parser.add_argument('filename', help='A required stl filename.', nargs='?',
                            const='TestWriteTriangleToFile.vtp',
                            type=str, default='TestWriteTriangleToFile.vtp')
        args = parser.parse_args()
        return args.filename

    def main():
        filename = get_program_parameters()

        Points = vtk.vtkPoints()
        Triangles = vtk.vtkCellArray()
        Triangle = vtk.vtkTriangle()

        Points.InsertNextPoint(1.0, 0.0, 0.0)
        Points.InsertNextPoint(0.0, 0.0, 0.0)
        Points.InsertNextPoint(0.0, 1.0, 0.0)

        Triangle.GetPointIds().SetId(0, 0)
        Triangle.GetPointIds().SetId(1, 1)
        Triangle.GetPointIds().SetId(2, 2)
        Triangles.InsertNextCell(Triangle)

        polydata = vtk.vtkPolyData()
        polydata.SetPoints(Points)
        polydata.SetPolys(Triangles)
        polydata.Modified()

        writer = vtk.vtkXMLPolyDataWriter()
        writer.SetFileName(filename)
        writer.SetInputData(polydata)
        writer.Write()

    if __name__ == '__main__':
        main()