The biggest challenge involved the number of dancers required to fill the dance floor, which was too many for the computer systems to manage all at one time. To overcome this problem each camera shot for the video had to be rendered multiple times (known as passes), with each "pass" rendering a different layer of dancers. When all passes had completed for each shot, the individual renders were layered together to form one composite camera shot containing all 800 dancers.
More information can be found by clicking the images in the gallery.