import vtk

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

    # setup points and vertices
    Points = vtk.vtkPoints()
    Triangles = vtk.vtkCellArray()

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

    # setup colors
    Colors = vtk.vtkUnsignedCharArray()
    Colors.SetNumberOfComponents(3)
    Colors.SetName("Colors")
    Colors.InsertNextTuple3(*colors.GetColor3ub('Red'))
    Colors.InsertNextTuple3(*colors.GetColor3ub('Lime'))
    Colors.InsertNextTuple3(*colors.GetColor3ub('Blue'))

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

    polydata.GetPointData().SetScalars(Colors)
    polydata.Modified()

    writer = vtk.vtkXMLPolyDataWriter()
    writer.SetFileName("TriangleColored.vtp")
    writer.SetInputData(polydata)
    writer.Write()


if __name__ == '__main__':
    main()

