The art-work - or interactive light-work - of Anthony McCall, who has a new exhibit at the Serpentine in London, can be appreciated here. Another piece on him here; and here. McCall began in the "happening" movie and art scene in the 1970s. But new technology has enabled him to take a big step forward:

Line Describing a Cone was made as a simple stop-frame animation, the camera filming a white-on-black drawing, gradually revealed, rotated on a drawing pin. The recent ones are of course made on computer, which accounts for their phenomenal complexity, as well as their perfect clarity of line and plane, their total control of coordinated movement – and (a downside) the fact that, if you look closely, the whole image breaks up into grid of little squares.