Laser Graffiti

Amazing. Imagine using an abandoned 18-story building as an etch-a-sketch. The people at Graffiti Reserch Lab in Netherlands put it together. A building in Rotterdam is the screen, 70 meters high. A green 60 milliwatt laser pointer is the drawing tool - hand-held. Its path is captured by a security camera and fed to the computer. Then a powerful DLP projector paints the image drawn. When I read the description I imagined a painful, slow process. Wrong. It is real-time. Fast. Watch the video at: PopSci.com Clearly some of the images are too ornate to be drawn by a hand-held beam. They were generated by another tool ahead of time. Here is the post inviting such submissions:

If you can’t make it to the Netherlands in February, send us your own animations and graphics for the LED facade on the KPN Building. The KPN Telecom building features a 70 meter tall low resolution LED facade. Send us your 22 pixel wide by 41 tall monochrome animated gifs or quicktime movies and we will convert them to work on the big screen.

Still, it's amazing. And the video shows some real-time drawing.