A central mechanic in my game involves shining a flash light on a glass sphere, which then focuses the light like a magnifying glass in order to burn enemies. The flash light was easy to implement - it's just a spot light - but the focused beam is turning out to be a little harder, since Unity doesn't seem to have any built-in light type that converges to a single point.
Currently, I'm using a flipped spot light. With that the illusion falls apart pretty quickly, since it casts shadows in the wrong direction and doesn't illuminate things the way you would expect it to.
Am I missing a light type that does what I need, or is there a trick to achieve such an effect?