Pumping up the Wattage with 'Crank: High Voltage'

At the end of Crank (2006), professional assassin Chev Chelios took a deadly fall from a helicopter hovering high above Los Angeles. Miraculously, he survived. In Crank: High Voltage (which opened Friday from Lionsgate), the action picks up immediately after this fall as Chev is transported to an operation room in which his seemingly indestructible heart is replaced with a battery-powered ticker that needs regular jolts of electricity to keep working...

Despite the tone and even premise of the movie, directors Mark Neveldine and Brian Taylor were adamant that Crank: High Voltage be absolutely real, visually, which meant that a lot of shots that might have been more easily accomplished via vfx were, at least initially, approached as shots to be done in-camera. Indeed, the total shot count in preproduction was... eight. However, despite all good intentions, not all that was planned to be done in-camera ended up being successful. Thus, the final shot count eventually reached 440, all supervised by Overall Visual Effects Supervisor (and Exec Producer) James McQuaide (Underworld: Evolution, The Cave, Underworld: Rise of the Lycans).

McQuaide has a strong track record of delivering hundreds of visual effects shots under tight budgets and tough schedules. Crank: High Voltage proved to be no exception. One of McQuaide tactics was to hold off starting work on any shot until the picture was locked. "On this type of movie, we cannot afford to throw anything away, so we wait as long as possible to start the work. On Crank: High Voltage, we had about two months to complete 400+ shots… but every single dollar that was spent on visual effects ended up on the screen. The exception to this strategy was the sequence where one of the main characters is on fire -- because of the number of shots and the amount of CG required. Mark Neveldine and Brian Taylor made it a point of editing this sequence first, which gave vendor Duran Duboi a whopping three months to complete these 21 shots," he says sarcastically.

Another of McQuaide's strategies was to rely on a network of proven vendors. "If you look at the credit lists of the 15 pictures I've supervised, you will see the same facility names again and again (i.e. Luma Pictures, Duran Duboi, LOOK Effects, Furious FX, Celluloid, etc.). First and foremost, it's these facilities that make it possible to deliver work as ambitious and well crafted as anything out there, and to do so on budgets that are a fraction of what they could very easily be. Also, on every show, we do quite a bit of the clean-up work and basic compositing in-house. On all the pictures I've supervised, you will see a credit for a company called Sub/Par Pix, which is basically my longtime associate, Gary Oldroyd, and whoever else we can rope in to helping us out -- we hire our runners based on whether they know Shake and/or After Effects."

Crank: High Voltage presented the challenge of adapting a rigorous vfx approach to a freewheeling, almost documentary shooting style. Up to 12 cameras were constantly rolling, with the main cameras being usually handheld. "It was difficult to make sure we had accurate camera data -- or as accurate as the digital cameras could allow for," McQuaide observes. "And getting matching background plates for all the foreground plates was a challenge too. Even on the bigger shows I've supervised, like the Underworld movies, I have, philosophically, always tried to have vfx maintain as low a profile on set as possible, so production wasn't hindered by our presence. On this picture, because of the way the directors shot, because of how fast production was moving, this was even more of an imperative but, at the same time, there were things we needed to have. So, finding and/or fighting for this balance was tricky."

Fire Challenges

The most challenging sequence featured a character on fire. In a series of 21 back-to-back shots, the costume starts burning and the fire progressively spreads out until the whole body is engulfed in flames. All this occurs as the character is immersed in a deadly fight. The plan in preproduction had been for a stunt double to do almost all the shots. However, during production, the directors became frustrated having to try and hide from the camera the face of the stunt double in every shot. So, they abandoned this plan and simply shot the entire sequence with the actor wearing a bit of burn make-up, a sweatshirt with holes cut in it and tracking markers.

The shots were assigned to Paris-based Duran Duboi, which had already collaborated with McQuaide on Underworld 3. "The fire is entirely digital throughout the sequence," says in-house Visual Effects Supervisor Thomas Duval. "The costume was never on fire. We had a lot of artistic decisions to make: Why is the character burning? Where does the fire start on his body? How fast does the fire expand and how? Is the skin burning too? If so, how far do we go in terms of realism? All these questions had to be answered. The sequence was especially tricky as it involved one of the main characters, and we needed to present a logical progression between shots."

Continuity was Duran Duboi's first concern, as the sequence had been edited for maximum impact, without consideration for the look of the actor in each individual shot. As often, shots that had been planned for the later parts of the sequence ended up being integrated at the beginning. As a result, the character looked dramatically different from shot to shot. "In some plates, he was wearing burnt prosthetics, in other ones, his skin was clean," Duval notes. "His costume could be damaged or not, with tracking markers or not. So, our first task was to create a sense of continuity by painting out anything that was appearing too soon in the sequence, and adding patches to fill up unwanted holes in the costume or to cover the prosthetics."

Duran Duboi's team, which included VFX Producer Annabelle Troukens and VFX Coordinator Judith Bruneau, received a cyberscan of the actor's head. The CG head was used to build a digital double that was precisely roto-animated to match the actor's movements in every shot. CG Supervisor Julien Lambert and his team then placed flame emitters on the animated body to create the fire effects. The flames were generated via a FumeFX fluid simulation within 3ds Max, and rendered via V-Ray and proprietary tools. "The CG fire would naturally follow any move that the character would make, which created a very realistic motion," Duval observes. "Early on, we looked into creating a visible progression within individual shots, such as showing the skin turning from white to red to black, but in the end, the shots were too brief for anything like this to read on screen. So, the progression was really created from one shot to the next. The skin was entirely recreated in CG and rendered via RenderMan."

Duval says that a good part of the realism of the whole sequence relied on a very subtle effect. "There were about 15 burnt holes in the costume, and the fire was supposed to start there. So, we tracked those holes and created a matte for each individual edge. Then, using color correction tools, we turned those edges into a glowing orange that perfectly simulated incandescent fabric. It really blended the digital fire in the plate. We also did a lot of work on the CG smoke, using FumeFX again."

Given the brutal nature of the effect, the team had to deal with a problematic gore issue. "The directors wanted a photoreal look for the fire itself, but something more stylized for the body injuries," Duval explains. "We submitted a lot of iterations, trying different textures and maps, working on various levels of realism. It was clear that this was not a gore movie, and that the character should never become truly disgusting to watch. So, we eventually used a softened approach, using red and black textures, but avoiding really gross -- but realistic -- textures. In the final shot, the character's face is entirely synthetic -- and that's in full close-up. The CG head was roto-animated to match the actor's performance down to the most subtle facial movements." Compositing Supervisor Cyrille Bonjean and his team assembled the various elements, included a 2D heat wave effect, using proprietary software Dutruc.

Duran Duboi also worked on a variety of 2D effects for the movie, including TV composites, Tazer electrical bolts, a cattle prod hitting a bad guy and even a horse penis for a humorous scene! Forty-one shots in total were produced in two-and-a half months with a team of 20. "We worked on a very tight deadline," Duval observes. "For a sequence that involved complex fluid simulations and the digital double of a key character, that was rather tricky..."

When Plates Don't Match

The other vfx-heavy sequence in the movie is a shootout in a limo -- more than 100 shots assigned to LOOK Effects. In-house VFX Supervisor Max Ivins and VFX Producer Melinka Thompson-Godoy oversaw the project. Like with the rest of the picture, the sequence was shot handheld to give the audience the sense that they are part of the action. As a result, McQuaide and his team found out that it was virtually impossible to shoot background plates that matched exactly -- at least technically -- the foreground greenscreen plates. In the end, they shot as much background coverage as possible, from angles as similar to those used to shoot the foreground plates as possible, and then pieced it together in post.

McQuaide notes that, because of the aggressively handheld approach, the foreground and background plates could never match exactly. "Also, we had to deal with significant budgetary limitations, especially since the sequence required over 100 composites. Eventually, we decided to simply blow out the backgrounds, so that there was enough visual information left for the audience to understand that the limo was moving, but not enough that mismatched lenses/angles would be apparent. The interesting thing is that blown out windows are completely appropriate given the picture's Los Angeles setting. So, while this approach was taken to save money, it actually ended up enhancing the sense of reality."

LOOK Effects used Shake and Flame for 2D compositing software and Maya for 3D software.

The shoot-out sequence, among similar scenes, involved a great deal of blood squirts and projections, an effect that was originally intended to be realized practically. But a recent experience led McQuaide to surprisingly opt for a fully-CG approach. "If you had asked me 18 months ago about doing CG blood, I would have said, without hesitation, that practical blood was the only way to go. At that point on various pictures, I had tried compositing blood elements, as well as using CG blood, and the final results had always felt artificial. However, on Underworld: Rise of the Lycans, I started working with a Berlin-based company called Celluloid. They were able to achieve CG blood that looked remarkably spot-on. In fact, their quality was so good that the directors, who are strong proponents of doing everything in-camera, are now talking about using CG blood exclusively going forward. It will save them the production time required to set the blood packs and clean up the resulting splatter -- particularly on wardrobe -- while still providing the reality they require."

All CG blood was simulated using Next Limit's RealFlow, creating defined shapes of flying liquid rather than just a particulate spray. After simulating, the liquids were rendered using Chaos Group's V-Ray renderer, which provided the opportunity to simulate accurate sub-surface effects and reflections. The finals were then output as multi-layered Open EXR files in unclamped float using The Foundry's Nuke, which gave Celluloid complete flexibility to create the final look of the blood.

Additional visual effects were created by FAUV: title sequence and motion graphics (41 shots); RIOT: clean-up work (116 shots); Therapy: motion graphics (nine shots); Max Erdenberger: motion graphics (five shots); and Sub/Par: wire and signage removal (145 shots).

Going the HDV Route

One of the most intriguing aspects of the project was that it was entirely shot on "prosumer" digital cameras, most notably the Canon XH-A1 (along with the Canon HF10). "It was truly a revelation," McQuaide says. "The picture easily looks as good as what you are used to seeing (if not better), but was shot with very little lighting and on cameras that cost less than $3,000. The image quality -- even using the HDV format at resolution of only 1440x1080 -- was such that it had no impact on how we dealt with vfx plates. It gave the directors the ability to cover the action in ways that the use of pretty much any other camera would have precluded. I believe this is the first time a major feature film has been shot on the HDV format and, given our results, can't imagine it will be last."

Alain Bielik is the founder and editor of renowned effects magazine S.F.X., published in France since 1991. He also contributes to various French publications, both print and online, and occasionally to Cinefex. In 2004, he organized a major special effects exhibition at the Musée International de la Miniature in Lyon, France.