Unfortunately LightDM can't help here - it's just run a standard X server and the greeter inside it. So to support transparent windows either X needs to be informed of this or perhaps this is the function of a window manager (which pantheon greeter will be acting as in this case). Sorry I don't know enough about transparent windows to say where exactly.
Unfortunately LightDM can't help here - it's just run a standard X server and the greeter inside it. So to support transparent windows either X needs to be informed of this or perhaps this is the function of a window manager (which pantheon greeter will be acting as in this case). Sorry I don't know enough about transparent windows to say where exactly.