click-and-drag to draw on the scene with an invisible marker ! click the button in the lower corner to turn off the lights click the button again to turn on the blacklight (ultraviolet light) click green flag again to paint on a different scene you can also draw while the blacklight is on :) keyboard shortcuts: space - activate light switch left/right arrows - change scene u - undo
the invisible ink absorbs UV light, which is invisible to humans, and re-emits it as visible light inspired by the lights studio
