When it came out in 2000, Pitch Black took science-fiction aficionados by surprise with a charismatic anti-hero (played by Vin Diesel), innovative creature design and a very effective less is more visual approach. The film was produced on a shoestring budget, but four years later, director David Twohy got all the money he wanted to put his epic vision on screen for the sequel. It is a vision that encompassed no less than three different worlds, six classes of starships and some nasty alien creatures. In this new adventure, Riddick is caught in the middle of an invasion by a planet conquering religious sect, the Necromongers. Eventually, he becomes the key to the future of all beings in the galaxy.
To supervise the ambitious vfx work, Twohy tapped Peter Chiang, who had overseen the visual effects on his two previous movies, Pitch Black and Below. Originally, about 600 effects shots were planned with three facilities evenly sharing the workload: Double Negative, Rhythm & Hues and Hammerhead. Ultimately, the movie ended up featuring more than 800 effects shots.
One hundred and forty of these shots were created by Double Negative under the supervision of Tom Debenham and Jesper Kjolsrud. There was one sequence that was pretty complex from a conceptual point of view, Kjolsrud says. The bad guy, whose name is Lord Marshal (Colm Feore), has the power to send his astral body in a direction and to project himself very quickly in its trail. During his climactic fight with Riddick, it gives him the ability to strike at light speed while avoiding being hit. It took us a very long time to develop a look for this effect. In fact, we were still refining it six weeks before the films release.
Originally, Twohy wanted the effect to look as if the camera shutter had been left open while filming the actor. However, early tests demonstrated that this approach produced very static results. We ended up using a combination of live-action elements and 3D animation to make it work, Kjolsrud explains. Basically, what we did was to photograph the actor on a green screen at the start point of his move, then at the end point. On either side of the main camera, we had two extra 35mm cameras equipped with wider lenses in order to capture the whole action. These plates allowed us to triangulate the exact position of the actor and to track his moves onto a CG double. Using Maya, we then animated the ghost version of the character to run at light speed across the set until it blended into the actor in its final position. The streak itself was generated in 3D via a proprietary particle renderer combined with RenderMan.
The most complex shots of the fight required intricate planning of the plate photography. Sometimes, Vin and Colm were shot together on a greenscreen, Kjolsrud says. But there were shots for which we had to photograph them separately. Vin would rehearse his moves with four or five stuntmen playing Lord Marshal materializing everywhere around the character. Once the choreography was in place, Vin performed the action alone, using tennis balls to hit his marks. We then timed the animation of our CG Marshal ghost to respond to his movements. All Double Negative shots were composited in Shake.
Gone with the Wind
The tri-camera methodology developed for Lord Marshal was later applied to Aeron, an alien character played by Judi Dench. Although she appears in a human form most of the time, Aeron becomes transparent when hit by a strong wind. The wind brings her back to her original alien form, a shape made of smoky material, 2D Lead Mike Ellis reveals. The more wind, the more transparent she becomes. We did a cyber scan of Judi and shot the plates with tracking marks on her face. Then, we replaced her with a CG double that was animated to follow her every move. It was filled up with volumetric smoke and particles that were all contained within the volume of her body. However, in our first attempts, the effect looked too flat. So, we added an extra layer revealing the rear side of her body through the smoke. It gave us a sense of depth for the character and made the effect much more interesting.
Besides character-related effects, Double Negative handled several complex shots involving spaceships. One of these shots was more than 800 frames long. In this shot, the camera follows a ship as it flies above water, over sand dunes and finally reaches a massive city, Kjosrud recalls. The whole journey is completely synthetic. The water was generated with proprietary software that we had developed for Below and then refined for the Nautilus shots of The League of Extraordinary Gentlemen. The city was a matte-painting created in Photoshop and projected onto 3D geometry. As for the ship, it was a CG model that wed built and later sent to Rhythm & Hues for their own sequences. We started designing the shot on the very first day of the production and kept working on it until two weeks before the films release. At the beginning of May, the animation was still not locked in. It just kept changing and evolving. Ultimately, this one shot was nine months in the making.
Welcome to Hell Prison
While other facilities had work spread throughout the film, Rhythm & Hues work focused on two major sequences. We did 135 shots for the film, observes visual effects supervisor Mike Wassel. The majority of our work appears in the Crematoria sequence. Riddick finds himself captive in a prison buried below the surface of the planet. During the day, the surface temperature of Crematoria rises to 700° and at night, falls below -300°.
The main area of the prison, a 200-foot deep pit, was created via a combination of set elements and miniatures. Live-action plates were shot in a two-story high set built on stage in Vancouver. The upper levels were later realized as a 1/8-scale miniature, while the deeper lower sections were built at 1/16-scale. Both were later composited with the live-action plates in order to extend the set vertically. The different levels were populated with CG prisoners rendered with our in-house software, comments Wassel. Most of the tools we used on the show are proprietary. Rhythm & Hues also created the Hell Hounds, dog-like creatures that guard the prison.
One tricky hound shot had Riddick hiding behind a waterfall only to be discovered by one of the creatures. The shot in which the hound slowly pushes its head through the water was very challenging. During preproduction, we shot video reference of a dog-head mannequin moving through the practical waterfall. But for the actual shot in the film, we photographed the background set clean. With the video reference as a guide, we used software developed here at Rhythm & Hues to run the fluid simulation. That simulation had to run for nine days, but it gave us an accurate motion analysis of how the water interacts with the dog. From that data we created several layers of elements, which were composited with the live-action plate.
Outrunning the Sunrise
When Riddick finally escapes the prison with several other inmates, he must very quickly reach a safe place before being burned down to ashes by the rising sun. The run on the volcanic terrain was photographed on sets that were augmented with CG extensions, reveals Wassel. Mostly matte-paintings. In some instances, the actors were extracted from the live-action plate altogether and composited in a CG environment. It allowed David to frame the shots in ways that were impossible to achieve on the stage. The escape sequence features a crash back from the ground to planet. A pullback combining three live-action plates shot simultaneously. We started with a tight shot on Vin Diesel and transitioned to a wider shot of the whole group. We then switched to a long shot of the characters before transitioning to a completely CG environment.
The main effect of the escape sequence was the gigantic heat wave created by the sun. The Visible Thermal Front, or VTF, destroys everything in its path, remaking the planet surface everyday. The VTF was generated via a series of fluid simulations that needed to interact with the terrain.
David didnt want the heat wave to look like fire or a dust storm. After a long period of development, we ultimately came up with a unique look thats self-luminous. Not dust, not fire, but something weve never seen before.
Planets and Spaceships
There is no true space opera movie without spectacular spaceships and exotic planets. On The Chronicles of Riddick, many of these shots were awarded to Hammerhead with company co-founder and president Jamie Dixon supervising the effort. We had about 90 shots to create, all of them involving CG spaceships or virtual planet environments. One of the most important sequences we worked on was the aerial battle between the Necromongers armada and the fleet defending the main planet, Helion. David wanted to use the visual approach that had been so successful on Pitch Black, an ambiance of mystery in which you never completely see whats going on. Indeed, during the battle, the ships are never fully lit, but briefly illuminated by all the flashes and flak from the battle instead. The image almost has a strobe light quality.
The Helion ships were CG models provided by Double Negative and heavily modified by Hammerhead. Both companies created numerous shots involving those ships, but Chiang cleverly split the workload in daytime and night-time sequences, Hammerhead being assigned the later.
In some shots, several thousand ships are seen flying around. The main units were hand animated while the bulk of the armada was generated via procedural animation. When you look at the shots, there are explosions and flashes everywhere, Dixon notes. It all looks random but it fact, every single event is calculated to direct the viewers attention to the part of the image where we want it to be. Another massive sequence that we worked on was the arrival of the Lord Marshal after the Necromongers victory. He walks down an enormous staircase while spaceships hover in the background and thousands of soldiers look on. Except for the actors on the staircase, the image is entirely synthetic, including the Necromongers army.
In one of these sequences, a spaceship crashes right behind Riddick and flips over him. Hammerhead created the shots by combining multiple elements. I wouldnt say this was the easiest sequence we worked on Dixon laughs. We had a plate of Vin Diesel running in front of a greenscreen. The ship and the street environment were New Deal Studios miniatures, shot separately. We composited these elements and augmented the effect with explosions shot on black, CG debris, camera shake, volumetric smoke and various atmospheric effects. What really sold the shot was the camera shake: we worked a lot on that particular element to get it just right.
To be Continued?
With its operatic tone, imaginative visual style and spectacular effects work, The Chronicles of Riddick will certainly strike the imagination of science-fiction fans around the world. As the Star Wars saga comes to an end next year, Riddicks outer space adventures could very well become the next franchise in the genre.
Alain Bielik is the founder and special effects editor of renowned effects magazine S.F.X, published in France since 1991. He also contributes to various French publications and occasionally to Cinefex.