 Visual effects at <unk> were supervised by Bert Yukich and produced by Amy Yukich . A key part of the video is a 24 @-@ second visual effects sequence in which Rihanna is surrounded by silvery strands of liquid that crisscross the frame in graceful arcs in response to her movements . Water elements were recorded on a special effects stage using a high @-@ speed 35mm camera . Bert Yukich then composited them into the scene with the singer . He then added lighting effects to the practical water elements to give them the mirror @-@ like texture of mercury . 
