Yes. In the project settings, input map, when you add an action, there is the option to add the modifiers alt, ctrl, shift or meta (whatever the last one is). Also in combinations like shift-ctrl.

    Pixophir
    Sorry, I wasn't clear enough. I mean button node + control / shift click?

    Megalomaniak

    Oh, that ! I must have a scotoma there, actually two, looking down ... :-)

    duane
    Decided to go with is_action_pressed(). Either way your reply steered me towards using the Input class which is the winner. Thank you!