http://vtk.1045678.n5.nabble.com/Should-I-use-one-actor-per-renderer-renderwindow-or-can-they-share-the-same-actor-td4954889.html http://vtk.1045678.n5.nabble.com/Adding-an-ImageSlice-to-one-renderer-causes-the-image-to-disappear-from-a-different-renderer-td4759415.html
