Double Negative Weaves Magic For Stardust.

Leading Visual Effects house, Double Negative created magical visual effects for the Paramount Pictures production, Stardust, which is released in the United States today. Stardust is the latest outing for director Matthew Vaughn (Layer Cake and producer of Snatch and Lock, Stock and Two Smoking Barrels) and is a fanciful tale about a young man who ventures into a magical land in order to retrieve a fallen star at the command of the woman he loves. Double Negative was delighted when Production VFX Supervisor Peter Chiang approached them to help develop and provide the major visual effects for the film.

The idea for the original graphic novel fell to earth as Neil Gaiman watched a falling star in the middle of the Tuscon desert in 1991. Gaiman went on to work with conceptual artist, Charles Vess to create the popular graphic novel and the story was later adapted for the screen by Vaughn and writer/journalist Jane Goldman. Led by Digital Supervisor Mattias Lindahl and VFX Producers Matt Plummer, Andy Taylor, Clare Tinsley and VFX Co-ordinator, Emma Larrson, Double Negative produced 350 shots, making them the lead vendor on the film.

Double Negative involvement on the film started early, with Matthias Lindahl pre-visualisation team based in Pinewood immediate to the Production Art Department and Director Matthew Vaughn. Chiang remembers, ‘We needed to get inside his (Vaughn) vision and then show a representation of what we thought he wanted, then build on that to make it right for him.’ The Double Negative team helped to influence the creative side from the beginning, says Chiang, ‘Vaughn had a very clear vision about the way the world should look and felt that the simpler the process the better. As he became more familiar with the techniques that were available to him, he continued to refine his approach to the effects. This was great, as it meant he had a completely open mind and an ?‚àö√ë‚àö‚â§innocent’s approach that the film benefits from.’

The main areas of work for Double Negative included the extensive photo-realistic environments, the Sky Vessel flown by Captain Shakespeare, sky replacements, greenscreens and the magic effects used to differentiate between the different witches. The most difficult sequence made heavy use of the main areas of visual effects, namely the vessel and the environments.

Sky Vessel
The Sky Vessel was designed by the production designer, Gavin Bocquet and went through some minor alterations to its balloon shape during post-production. CG Supervisor, Rick Leary, designed the mechanism and dynamics for opening and closing the lightning nets. The director had been very clear in his brief for the look, the vessel must look ‘Victorian’ and it must look the worse for wear. A major section of the Sky Vessel hull was built within a greenscreen set at Pinewood with a heavily distressed look. It was Double Negative task to match the Sky Vessel identically with digital set extensions in keeping with this look. ‘Most sky vessel shots need cg topping up on the set construction and in some shots the entire vessel was replaced.’ recalls Leary.

The Double Negative team on the Sky Vessel were led by Digital Supervisor, Mattias Lindahl, CG Supervisor, Rick Leary, 2D Supervisor, Paul Riddle and 2D Sequence Lead, Matt Twyford. Leary started work on the film early on in shooting when he began to model the vessel himself from the blueprints provided by the Art Department. Once the full-size section of boat had been constructed onset in Pinewood, Leary, along with texture artist Guy Williams, photographed every inch of the set to extremely high resolution (approx 40,000 lines, bow to stern). In the meantime, the modelling crew based back at Double Negative (Jez Smith, Jordan Kirk, James Guy and Emily Cobb) were able to make the boat to a high level of detail and accuracy. James Guy was then able to stitch the texture reference photographs together in Double Negative proprietary software, STIG and used other in-house tools, dnPhotofit and dnPlaneit to project and bake the textures.

The remainder of the texturing of the boat’s hull and decks was undertaken by Guy and Look Development Artist, Bruno Baron. Meanwhile the balloon, rigging and flags were modelled by Kirk and rigged by Gia Sadhwani.

By filming in front of a complete 360 degree green-screen cyclorama, Peter Chiang was able to offer the Director and Director of Photography, Ben Davis, the flexibility to shoot from any angle, safe in the knowledge that the ship could be invisibly extended in any direction.

Whether the camera was contained within the confines of the ship or free to drift far away into the air, the compositing team, led by 2D Supervisor Paul Riddle, delivered a seamless transition from the live action set into the precisely matched CG ship, even in a scene set within a raging storm which had the additional complexity of dense falling rain. Integral to the Sky Vessel sequence, was the need to illustrate the passage of time and 2D Sequence Lead Matt Twyford, was able to facilitate this by creating a palette of looks, from early dawn, through midday sun to falling dusk.

Another major aspect of the work for Double Negative were the CG environments, VFX Supervisor, Chiang recalls, ‘As we started shooting we realized that Matthew (Vaughn) wanted to move the camera in a particular way and that opened up the environmental effects.’ The geography is needed to show the relation of the real world to Stormhold and those environments were used for the sky vessel sequences and many other points in the film. Chiang wanted to see amazing vistas that would show the huge magical Kingdom of Stormhold. The live action locations were in Iceland and the Isle of Skye and this provided guidance to the types of mountains and geography that were required, but outside of this the Double Negative team were given a fairly free hand to design the landscape as they saw fit.

For the Sky Vessel shots, TECTO Survey data of the Isle of Skye was used for the near ground and a 3D cyclorama of tall mountains was constructed for the background. All the clouds were rendered in DNB, Double Negative Voxel Rendering System and the clouds constructed by the cloud team under the supervision of 3D Technical Supervisor, Gavin Graham. The environment shots travel over a huge distance and needed to kept photo-real. TECTO and dnCloud were both modified since their first outing on the World War I aerial film, Flyboys, which Double Negative had worked on the year before and the additional functionalities were a huge step forward.

The Stardust environments covered huge distances that required a much greater volume and diversity of clouds. This demanded a library that needed to be extensive but also flexible, including clouds that could be made up of 3 to 10 ‘cloudlets’ allowing the shape to be modified on demand. The storm clouds required more sophistication and were created from greater numbers of smaller particle clumps that continuously rolled, expanded and moved independently, this particle work was carried out by Dynamics T.D., Nicholas New. Says Lindahl, ‘Previously the clouds were ‘out of a box’ and couldn’st do much, the modifications made for Stardust meant that the clouds could be rendered out on different channels, this allowed the compositor to grade them according to the requirements of the shot. Daytime to night-time, overcast or bright sunshine, all the tools were there so that the artist could do what they needed.’ Other Double Negative proprietary softwares, dnCloud and gtoMunge were also used, providing the artist a means to preview the clouds at low resolutions inside of Maya, so they could work on layout in real time.

The sky dome was created from photography, which was stitched together with STIG and rendered 24k latlong. The vessel was then matchlit and digital doubles setup for the deck. Says Lindahl, ‘The film is a fairytale and so a lot of the VFX were required for major story points and had to demonstrate the geography of the world that we are taking the audience into, so it was magical, but also had to be realistic. This is a fine line to walk and a challenge that we had to measure up to.’

On his odyssey, Tristan finds the star, which has transformed into a girl named Yvaine (Claire Danes). However, Tristan is not the only one seeking her. A king’s (Peter O’Toole) four living sons ?‚àö√ë‚àö¬® and the ghosts of their three dead brothers ?‚àö√ë‚àö¬® all need the star as they vie for the throne. Tristan must also overcome the evil witch, Lamia (Michelle Pfeiffer) who needs the star to make her young again. Tristan encounters more than one witch on his journey and each one required ‘signature’ magical effects. Lamia green magic effect was briefed initially as a fluid, controllable fire, however the brief evolved quite rapidly to vary the effect from a gentle twisting finger of flame to a raging inferno. The intensity of this is dictated by Lamia’s emotional state. The evolving brief required a change of approach to the magic effects and required a far greater range of characterisations, 2D Sequence Lead, Christoph Salzmann utilised both photographic elements and CG fire to realise this and Dynamics TD, Pawel Grochola developed a novel approach to generating 3D fire using particle and joint-driven softbody “ribbons”.

Another witch who was central to the storyline is Sal. Sal magic effect was briefed as ‘black smoke’ and a great deal of design work was done in-house under the supervision of Gavin Graham, regarding its movement and technical execution. Sal smokey magic was used to illustrate transformations, such as a mouse being turned into Tristan and back again. Says Graham, ‘Normally you would create a smokey figure, turn it into a cloud of smoke and reverse it, but Sal smoke needed to be more sophisticated than that.’ In fact the colours of the original object needed to flow through the smoke effect and then recreate themselves into the final outcome. Vaughn wanted this magic to feel rooted in reality so the look needed to be gritty and dirty, like diesel smoke. With fluid simulations being notoriously difficult to art direct, 3D artist Bjorn Henriksson used a wide variety of Double Negative’s in-house fluid tools to turn animated geometry into a target-driven fluid simulation in a manner that allowed for a more sophisticated effect – with efficient turnaround – than out-of-the-box simulations would allow.

While Stardust material really lends itself to VFX it was an extremely diverse project in terms of content, leading to many ?‚àö√ë‚àö‚â§one-off’s visual effects and meaning that nothing was predictable.
Says Chiang, ‘It an amazing, magical, fantastical film. The design reflects the simplistic environment and a combination of the simplistic approach combined with the sophistication of the VFX toolbox creates a really exciting combination. Matthew (Vaughn) always thought hard about the look of what he wanted, identifying the bare roots that would support the narrative. This was very liberating in a way and makes you think of the effects very differently.’

In total Double Negative worked on 350 shots. Stardust is released in the US on August 10th, 2007 and will be released in the UK on October 19th, 2007.

About Double Negative
Since its formation in 1998, Double Negative has firmly established itself as a leading player in visual effects production worldwide. Located in the heart of London’s Soho, the company is a pre-eminent visual effects studio with more than 70 feature films to its credit. Led by Managing Director Alex Hope and CEO Matt Holben, Double Negative is capable of handling projects from initial design through on-set supervision and production to post-production. All key post-production technologies are available in-house to allow for maximum flexibility,

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