基于qt5 vtk6.3。已经用vtkpolydata建立了线条，然后参照官网SelectAVertex的例子用如下代码修改了某个选取得点:
vtkPolyData* Data = vtkPolyData::SafeDownCast(Actor_->GetMapper()->GetInput());
Data->GetPoints()->SetPoint(.....);
Data->GetPoints()->Modified();
Data->Modified();
vtkPolyDataMapper::SafeDownCast(Actor_->GetMapper())->SetInputData(Data);
Actor_->GetMapper()->Modified();
Actor_->GetMapper()->Update();
Actor_->Modified();
this->GetCurrentRenderer()->Render();
this->GetCurrentRenderer()->GetRenderWindow()->Render();
（qvtkwidget也刷新了）
然而线条就是没有任何改变！这是怎么回事？