# UnstructuredGridReader

VTKExamples/Python/IO/UnstructuredGridReader

### Description

The following example demonstrates how to read an unstructured grid defined at a (legacy) *.vtk file and how to render it with VTK.

An example input file is uGridEx.vtk (folder Data at VTKData)

### Code

UnstructuredGridReader.py

    #!/usr/bin/env python
    # -*- coding: utf-8 -*-
    #
    # by Panos Mavrogiorgos, email: pmav99 <> gmail

    import vtk.vtk

    # The source file
    file_name = "uGridEx.vtk"

    # Read the source file.
    reader = vtk.vtkUnstructuredGridReader()
    reader.SetFileName(file_name)
    reader.Update()  # Needed because of GetScalarRange
    output = reader.GetOutput()
    scalar_range = output.GetScalarRange()

    # Create the mapper that corresponds the objects of the vtk.vtk file
    # into graphics elements
    mapper = vtk.vtkDataSetMapper()
    mapper.SetInputData(output)
    mapper.SetScalarRange(scalar_range)

    # Create the Actor
    actor = vtk.vtkActor()
    actor.SetMapper(mapper)

    # Create the Renderer
    renderer = vtk.vtkRenderer()
    renderer.AddActor(actor)
    renderer.SetBackground(1, 1, 1)  # Set background to white

    # Create the RendererWindow
    renderer_window = vtk.vtkRenderWindow()
    renderer_window.AddRenderer(renderer)

    # Create the RendererWindowInteractor and display the vtk_file
    interactor = vtk.vtkRenderWindowInteractor()
    interactor.SetRenderWindow(renderer_window)
    interactor.Initialize()
    interactor.Start()