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The first major action sequence in Iron Man 2 occurs during the Monaco Grand Prix, in which Tony Stark (Robert Downey Jr.) impulsively enters the race and Whiplash (Mickey Rourke) makes a grand entrance and activates his lethal electric whips, slicing both the lead car and Stark's in two.

London-based Double Negative handled the electrifying, 250-shot sequence led by Ged Wright, the visual effects supervisor. The Dneg team also included Victor Wade (2D supervisor), Katherine Roberts and Jordan Kirk (co-CG supervisors). The Singapore office, meanwhile contributed compositing work throughout.

DNeg's work encompassed three areas: recreating Monaco (including crowds and historic cars); Whiplash's electric whips and their damage and destruction; and the MarkV Iron Man suit-up and armor.

DNeg accompanied the 2nd unit crew to Monaco in May of last year (just before the Grand Prix) to shoot digital stills, collect reference video and gather Lidar and survey data for the entire racing circuit and most of the surrounding city and terrain. In June, principal photography began at Downey Studios in LA, where a partial recreation of the fight area was constructed. DNeg collected extensive reference data of the Downey set to build a digital equivalent to incorporate into the wider digital Monaco.

The team took 100,000 digital stills, most of which served as the basis for the digital Monaco. Track, barriers, chain-link fence, stands and press box were all modeled and textured. The 500-foot-long Downey set was further extended to incorporate authentic Monaco surroundings (15 yachts populate the visible waterfront), and was once again modeled and textured.

In addition, distant Monaco was recreated using high-res digital stills shot on location and combined into a 360-degree HDR, gigapixel panorama using DNeg's proprietary stitching software, Stig, which was then exported as multiple high-res matte painting tiles to remove all unnecessary foreground objects and add flags and banners to the buildings before being recombined as a proper backdrop.

Every car in the race is digital, for which DNeg created two highly detailed digital versions for each of the 11 cars. In fact, five art department cars were built specifically for the Monaco race and six genuine vintage Grand Prix cars were brought in to supplement the grid. Throughout the sequence, sprite crowds and practical crowd elements were used to populate the stands and buildings with CG agents used to break up the sprite crowd.

In keeping with the creation of the Iron Man Mark 1 suit, the Whiplash rig is homemade and very rough around the edges. According to Double Negative, this prototype quality was important in defining the quality of the whips. Although the whips slice through Iron Man's armor and generate a powerful stream of plasma, which runs along the length of the whip, the engineering is crude and prone to leakage. Also, the power source of the whips is similar to Iron Man's RT and required a similar repulsor blast look established in the first film.