• The VFX of Charlie's Angels: Full Throttle
    Words: Leonard Teo & Mark Stetson, 21 July 2003

    Directed by McG (pronounced "mac-gee"), Charlie’s Angels: Full Throttle is the sequel to the wildly successful action adventure based on the popular television series of the 70's. Cameron Diaz, Drew Barrymore and Lucy Liu reprise their roles as Natalie, Dylan and Alex, undercover agents reporting to Charles Townsend (Charlie). Sony Pictures Imageworks was the primary studio responsible for most of the film’s visual effects, with veteran Mark Stetson at the helm of the project. Altogether, Imageworks produced 475 of the film’s 900 effects shots over a twelve month period, wrapping up in May 2003.

    Effects from the get-go
    The opening shot in the film is a continuous camera move travelling through a Mongolian bar, down to the basement, back through the ceiling where we find Drew Barrymore’s character in a drinking contest. The camera follows her as she steals a set of keys and finally reveals the front door, where Cameron Diaz’s character Natalie bursts through squealing “This is hostel, ja?” This entire sequence is comprised of 16 camera shots, plus the Columbia logo elements, all stitched together with some CG glue and glitter, into one long, continuous shot.

    Immediately following this is a bar fight sequence where visual effects consist mostly of wire rig removals. The angels narrowly escape a nasty bar brawl punctuated by machine gun fire by leaping through the bar’s tall windows (which were also CG) and running onto a dam where the most intensive visual effects sequence of the movie takes place.

    Next Page - The Mongolian Dam >>


    Above: Mark Stetson, Sony Pictures Imageworks VFX Supervisor for Charlie's Angels: Full Throttle.

  • The Mongolian Dam

    The most visual effects intensive sequence for Full Throttle is the Mongolian Dam, where the Angels flee with newly rescued government agent Ray Carter (Robert Patrick). After commandeering a military truck, our heroines are trapped from both sides of the dam by a tank on one side firing at them, and a group of soldiers on the other launching an RPG. Our angels veer the truck off the side of the dam and in a mid-air plunge, escape in a helicopter, which happens to be on the back of the truck.

    Mark Stetson: There wasn’t too much that was real in this sequence. The roadway on top of the dam was real. Michael Riva (Production Designer) built a set in the form of a cul-de-sac that included some of the stone cliff face and a sand slope backed up behind the roadway. A guard shack and portions of the dam tower were built on top of Hanson Dam, a real dam in California’s San Fernando Valley, just north of Los Angeles. As this was a flood control dam and not a hydroelectric one as depicted in the film, the dam that we shot on was only about 30 feet tall. Most of the time the roadway in the film is the real dam and everything else including the slope of the dam and canyon walls are all CGI.

    Initially, we wanted to use miniatures. Once the sequence was approved, however, the studio’s marketing department was anxious to use this as the golden moment in the teaser trailer. To accomplish that, the shooting schedule was revised earlier, and some shots were done twice so the teaser could deliver without the Ray Carter character. Because of the tight turnaround, we didn’t have time to build miniatures, so we built CGI dam elements to expedite the matchmove pipeline.

    The canyon walls of the dam were projected paintings and the face of the dam comprised of procedural shaders at render time. Once the truck goes off the side of the dam, it is a completely digital truck. When the tank blows up, we also have a CG animated tank turret exploding. But no tanks or trucks were harmed in the shooting of this movie!

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    This establishing shot made use of a techno-crane at the dam location, which was a 30 foot tall flood-control dam in San Fernando, California. The roadway here is all real, and everything else is CGI or matte paintings. The characters were rotoscoped where they break the horizon, the tower is CGI, and everything else from where the road bends in the middle of the dam is CGI. All the distant vistas including the canyon walls are matte paintings.
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  • The Blossom Shot
    The Angels thwart the dual military assaults by driving the stolen truck off the side of the dam. In a stunning sequence known as the "Blossom Shot", the tarpaulin on the back of the truck is swept off as the truck tumbles down at terminal velocity, revealing a helicopter which Natalie starts up, rescuing all characters by a hair's breadth. The set of assets created by Imageworks were a CG truck and a CG helicopter. The CG models matched the full-size truck and a full-size partial mock-up of the helicopter interior and exterior. The life-size helicopter only consisted of the front and cockpit; there were no rotors or tail. It was always extended using CGI.

    Due to the difficulty of this sequence of shots, pre-visualization was an absolute essential -- not just to aid the filmmakers in planning shots, but also to establish the actual camera moves for the motion control rigs. Once the shot had been pre-visualized, the camera move was exported from Maya by Imageworks and Image G, the company which provided motion control services for the shoot, into Kuper motion control software. The pre-vis export pipeline was sufficiently robust that the moves could be exported to take advantage of the limitations of the green screen cove size and configuration of the stage.

    Mark Stetson: Where the shots were difficult, we shot them as separate elements. The toughest examples were the so-called Blossom Shot - everything blossoms out of the truck as it goes off the edge of the dam. Two of the girls get thrown off the helicopter; Lucy is almost hit by the tumbling truck, and then the camera hands off from Lucy to Drew, who dives down towards the helicopter. The camera whip pans as she dives past and finally cuts as she gains on the helicopter. This extremely non-intuitive camera move could only be designed by pre-visualization in Maya, then translated into motion control elements that took into account the stage configuration, the green screen position, the track placement, the capabilities of the girls in the flying rigs, and a myriad of other little details.

    No face replacements were used for this sequence. There were stunt doubles and at times we were mixing principals with their stunt doubles shot to shot. Within a shot, it might be that a couple of the girls facing camera are principals but the other girls facing away from the camera were stunt doubles. That way as you’re choreographing the shot and working all the rigging, you can use the stunt double as an anchor to help the physical performances of the other girls. This worked quite effectively.

    _

    In the spectacular "Blossom Shot", the tarpaulin on the back of the truck is swept off as the truck tumbles down at terminal velocity, revealing a helicopter which Natalie starts up, rescuing all characters by a hair's breadth.
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  • Helicopter Chase
    As the helicopter continues to fall, Natalie (played by Diaz) furiously tries to start it and the two other angels hold on for their lives. This sequence was shot on a green screen stage with a physical mock-up of the helicopter. Drew Barrymore and Lucy Liu were shot with wire rigs, which were removed in post.

    Mark Stetson: The girls were shot on a green screen stage for three sessions. Some of the shots were performed with motion control cameras but most of it was done with a hand operated techno crane and tracked later. There was a lot of manipulation of the green screen shots, particularly in painting their body positions, rig removal, scaling and tracking.

    Mic Rogers, the second unit director and stunt coordinator, did a lot of the choreography for this sequence. Matt Sweeney, the special effects supervisor produced the flying track and flying harness rigging.

    The helicopter itself was a partial mock-up which was later extended in CGI. In many cases, it was easier to produce a nicer looking helicopter by wiping out more of the original helicopter plate and replacing it with CG to match the rest of the lighting in the scene. As a result, there’s a lot more of the CG helicopter than the full mock-up. When we are shooting from outside the helicopter, the glass you see is CG that is composited. When inside, the helicopter, however, we used real glass to reflect the interior more naturally. In no cases were there any physical rotors. The rotors and the rotor hubs were all CG.

    One of the major bonuses in this entire production was the fact that we did a good job of preparing for the live shoots. We did our homework by preparing the pre-vis, bringing it to set and showing the filmmakers how the camera was going to move. These pre-visualizations included the positions of the green screen, stage and rigs all modelled in CG. This really helped the shooting go smoothly throughout production.

     

    << Previous - Blossom Shot
  • The Motorcross Sequence
    Another sequence that was effects intensive was the motocross sequence. For the most part, the sequences were all real stunts, but the ending where Emmers pulls out two guns and fires at the angels in a mid-air "bullet-time" sequence required VFX from Imageworks.

    Mark Stetson: I really admire the work that Mic Rogers and his team did on this sequence. The stunts were such high quality that I almost felt guilty putting any visual effects effort into it. Once people find out that there were visual effects in the shots, people think that most of it is fake. But so much of it was real that it was almost demeaning to do any visual effects on it. Obviously, as the action heightens and approaches near-fantasy, visual effects were needed.

    No CG bikes were used in these shots. We pre-visualized the whole sequence but it was all done as green screen composites. Second Unit Director of Photography Jonathan Taylor worked with the camera department, the special effects department and the stunt team to come up with bike rigs that could mount a 35mm camera to the sidecar, a 16mm camera on the motocross bikes and run them through the course. We also made great use of Spydercam aerial cable-rigged camera plates, and a motion control crane, the Image G Bulldog, which we had out on location for several plates.

    The big frozen moment "roundy-round" shot at the end of the scene was produced using motion control rigs. Again, this started as pre-visualization and once the shot was laid out, we broke it down to moves that could be shot both on location and on a green screen stage. It became particularly complicated because it turned out in certain instances that the camera crane was in the way of itself and riders. What ended up happening was that the rig used on location had the camera swinging from a central position, but on the green screen stage, the camera was reaching from the outside-in. Because of this, the camera passes were never an exact repeat pass, but it was doing the right thing between the passes and gave us the elements needed to do the composite.

    As the sequence gets more fantastical towards the end of the race, we used large speed ups in excess of 1000x. We also had a lot of clean up, paint and comp corrections.

    Keeping up with production
    According to Stetson, the most challenging aspect of Full Throttle was keeping up with the schedule, and the compressed time at the tail end of production.

    Mark Stetson: We had a lot to do. Time was our biggest enemy and we ended up going out to nine vendors for comp work, speed ups and rig removal during the frantic end phase. Despite that, it was a really fun production and you can tell that just by watching the film. The girls were so much fun to work with and McG (the Director) was great - very positive energy throughout production. Overall, it was one of the most fun movie-making experiences I’ve ever had! [CGN]

    Production Trivia
    Cameron Diaz really drove the truck on the Mongolian Dam sequence. She also took surfing lessons for the surf shots. The hero shot of her surfing through a massive curl, however, was actually a championship surfer shot in Hawaii, with face replacement and body-shaping work done by Imageworks using Inferno.

    In the shot where the tank explodes, there’s a little sparrow that hops up into the tank tread just as the missile flies in between the turret and the main hull. The bird wasn’t harmed!

    The orphanage where the girls go to find out about the Thin Man was shot on location at the Playboy Mansion. The name of the orphanage in the script (which never made it to the movie) was “Our Lady of Perpetual Virginity”.

    Leonard Teo is the Editor of CGNetworks. He needed a bib while watching Charlie's Angels: Full Throttle. Email him here.

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