Oh I had a play with this, see image.

Of course by the time I found the image AS had already replied.

I just used linear falloff to remove the round disc of light that would otherwise fall on the sand.

Measure your mind's height
by the shade it casts.
Robert Browning (Paracelsus)

Fran's Freestuff

http://franontheedge.blogspot.com/

http://www.FranOnTheEdge.com