Facade Printer: lo spara-murales!

The printer was constructed from a converted paintball system, hooked up to an industrial PC running custom software. Using the touchscreen, images in SVG format can be loaded from a USB drive and overlaid onto a digital photo of the blank wall; that allows the artists to frame the painting exactly. A laser is then used to indicate on the wall exactly where the paintballs will be fired – useful if you discover you’re currently standing where some high-speed Dulux will soon be approaching – before 5-10cm dots are created by the 200km/h colored balls.
http://www.facadeprinter.org/