The Space Painter machines create the illusion that glowing orbs are hanging and moving in space. Red, Blue and Green "orb-sets" can have different numbers of elements as well as different speeds and directions.
The technique of creating this illusion is unexpectedly simple. There is a single fast spinning illuminator orb containing 3 colors of LEDs, and each color is driven by its own pulse generator. By changing a color's pulse rate, its orb-set's apparent speed and number of elements will change. By adjusting the pulse duation, the apparent brightness is adjusted. The human eye's slowish response time (aka "persistence of vision") does the rest.
There is one delicate aspect to the electronics: The LEDs must pulse very briefly and very brightly, at currents far higher than the specified maximum currents. The LEDs have no current limiting resistors and will be destroyed by excessive pulse durations.
Horizontal type (below) and vertical "windmill" type (left) Space Painters have been built.