# Polyhedron

VTKExamples/Python/GeometricObjects/Polyhedron

### Code

Polyhedron.py

    #!/usr/bin/env python
    # -*- coding: utf-8 -*-

    import vtk

    def main():
        colors = vtk.vtkNamedColors()

        # create polyhedron (cube)
        # The point Ids are: [0, 1, 2, 3, 4, 5, 6, 7]

        points = vtk.vtkPoints()
        points.InsertNextPoint(-1.0, -1.0, -1.0)
        points.InsertNextPoint(1.0, -1.0, -1.0)
        points.InsertNextPoint(1.0, 1.0, -1.0)
        points.InsertNextPoint(-1.0, 1.0, -1.0)
        points.InsertNextPoint(-1.0, -1.0, 1.0)
        points.InsertNextPoint(1.0, -1.0, 1.0)
        points.InsertNextPoint(1.0, 1.0, 1.0)
        points.InsertNextPoint(-1.0, 1.0, 1.0)

        # These are the point ids corresponding to each face.
        faces = [[0, 3, 2, 1], [0, 4, 7, 3], [4, 5, 6, 7], [5, 1, 2, 6], [0, 1, 5, 4], [2, 3, 7, 6]]
        faceId = vtk.vtkIdList()
        faceId.InsertNextId(6)  # Six faces make up the cell.
        for face in faces:
            faceId.InsertNextId(len(face))  # The number of points in the face.
            [faceId.InsertNextId(i) for i in face]

        ugrid = vtk.vtkUnstructuredGrid()
        ugrid.SetPoints(points)
        ugrid.InsertNextCell(vtk.VTK_POLYHEDRON, faceId)

        # Here we write out the cube.
        writer = vtk.vtkXMLUnstructuredGridWriter()
        if vtk.VTK_MAJOR_VERSION <= 5:
            writer.SetInput(ugrid)
        else:
            writer.SetInputData(ugrid)
        writer.SetFileName("polyhedron.vtu")
        writer.SetDataModeToAscii()
        writer.Update()

        # Create a mapper and actor
        mapper = vtk.vtkDataSetMapper()
        if vtk.VTK_MAJOR_VERSION <= 5:
            mapper.SetInput(ugrid)
        else:
            mapper.SetInputData(ugrid)

        actor = vtk.vtkActor()
        actor.SetMapper(mapper)
        actor.GetProperty().SetColor(
            colors.GetColor3d("Silver"))

        # Visualize
        renderer = vtk.vtkRenderer()
        renderWindow = vtk.vtkRenderWindow()
        renderWindow.SetWindowName("Polyhedron")
        renderWindow.AddRenderer(renderer)
        renderWindowInteractor = vtk.vtkRenderWindowInteractor()
        renderWindowInteractor.SetRenderWindow(renderWindow)

        renderer.AddActor(actor)
        renderer.SetBackground(colors.GetColor3d("Salmon"))
        renderer.ResetCamera()
        renderer.GetActiveCamera().Azimuth(30)
        renderer.GetActiveCamera().Elevation(30)
        renderWindow.Render()
        renderWindowInteractor.Start()

    if __name__ == '__main__':
        main()