VTK 8.1 window will not completely close on Ubuntu 16.04 when run from IPython 6.2.1
IPython 6.2.1, VTK 8.1.0, Python 3.6.4, QT 5.10.0, built from source using gcc 7.2.0 on Ubuntu 16.04
When you run one of the VTK/Python examples, such as the Cell3DDemonstration example, in IPython the dialog comes up with the properly functioning test. Clicking the x to close the dialog leaves a static image of the dialog on the screen that only goes away on closing IPython. Running the script directly with python 3 shows complete closing of the window on clicking the x.
This erroneous behavior is not seen with a build from these sources on MacOSX High Sierra 10.13.2.