polydata leaves black area when it shouldn't
please see following example
import vtk
xs = [-70.0, -66.0, -62.0, -58.0, -54.0, -50.0, -46.0, -46.0, -50.0, -54.0, -58.0, -62.0, -66.0, -70.0]
ys = [97.40004179212772, 99.24051369561087, 99.64501380920407, 99.50791666242807, 99.25809764862053, 98.72724999321828, 97.86243057250978, 66.1760279867384, 78.08891693751016, 84.6064443588257, 75.83586128552756, 54.88270839055378, 33.08841943740845, 32.207757042513954]
N = len(xs)
pts = vtk.vtkPoints()
for i in range(N):
pts.InsertNextPoint(xs[i],ys[i],0.)
polygon = vtk.vtkPolygon()
polygon.GetPointIds().SetNumberOfIds(N)
for i in range(N):
polygon.GetPointIds().SetId(i,i)
polygons = vtk.vtkCellArray()
polygons.InsertNextCell(polygon)
polygonPolyData = vtk.vtkPolyData()
polygonPolyData.SetPoints(pts)
polygonPolyData.SetPolys(polygons)
mapper = vtk.vtkPolyDataMapper()
mapper.SetInputData(polygonPolyData)
actor = vtk.vtkActor()
actor.SetMapper(mapper)
renderer = vtk.vtkRenderer()
renWin = vtk.vtkRenderWindow()
renWin.AddRenderer(renderer)
renIter = vtk.vtkRenderWindowInteractor()
renIter.SetRenderWindow(renWin)
renderer.AddActor(actor)
renderer.SetBackground(.5,.3,.31)
renWin.Render()
renIter.Start()