Python Plugin with virtualenv

Hi

I just set up my first project with IntelliJ and the Python Plugin (not PyCharm). I am used to virtualenv from the Terminal, where you usually activate and deactivate projects all the time. How is this done in IntelliJ, how can I trust that installations happen in my project's virtualenv and not globally? (I know I can set the Python SDK to be a virtualenv version, so maybe that's the only thing that is needed...)

Thanks for your explanations
Katrin