code: def redraw(self, reset_camera=False):
          
          self.ren.RemoveAllViewProps()
          self.picker = None
          self.add_picker_fixed()
          self.helptxt_mapper = vtk.vtkTextMapper()
          tprops = self.helptxt_mapper.GetTextProperty()
          tprops.SetFontSize(14)
          tprops.SetFontFamilyToTimes()
          tprops.SetColor(0, 0, 0)
  
          if self.structure is not None:
              self.set_structure(self.structure, reset_camera)
  
          self.ren_win.Render()
docs: Redraw the render window.
  
          Args:
              reset_camera: Set to True to reset the camera to a
                  pre-determined default for each structure.  Defaults to False.