A bunch of MIT guys decided to invent a swarm of micro LED-equipped heli-robots that would hover autonomously in the sky and create massive works of floating 3D artwork. Their idea is based upon each heli robot, who carries a led and can be synchronized with the others so that can produce 3d artwork in the Sky. The project is called Flyfire and it is initiated by the SENSEable City Laboratory in collaboration with ARES Lab (Aerospace Robotics and Embedded Systems Laboratory) aims to transform any ordinary space into a highly immersive and interactive display environment.
As we read in their site
With the self-stabilizing and precise controlling technology from the ARES Lab, the motion of the pixels is adaptable in real time. The Flyfire canvas can transform itself from one shape to another or morph a two-dimensional photographic image into an articulated shape. The pixels are physically engaged in transitioning images from one state to another, which allows the Flyfire canvas to demonstrate a spatially animated viewing experience.
The following video shows the concept