And usually we can SetPointSize and LineWidth using vtkActor. But I have large amount of polydata, some of them include lines, some of them include points, I want to set line width and size seperately, and then merge them to one polydata and one vtkActor and render them. This will be more efficient. So how can I do?
It is not possible to specify visual properties on vtkPolyData.
That being said, you can render all your vtkPolyData with one actor. Group all your vtkPolyData into a vtkCompositeDataSet and use vtkCompositePolyDataMapper with one vtkActor.