I want to create an indoors map (probably in a terran building) where all the lights have gone out, and the player should not be able to see anything. I then want to provide the player with a flashlight as his only means of visibility, that points in the direction the unit is facing, which follows the mouse cursor.
Objects shone on by the flashlight should reflect that light, and solid objects should naturally prevent light from passing through.
Not sure if this is relevant but, it seems there is a widespread issue at the moment preventing everyone from downloading Patch 9 which contains the editor. Blizzard staff have not yet made a post about a fix.