CGSociety :: Production Focus
13 June 2012, by Paul Hellard
*** SPOILERS AHEAD ***
Prometheus, the long awaited science-fiction from Ridley Scott, has emerged as a spine-chilling reveal to his earlier Alien masterpiece. In Prometheus, a team of explorers discover a clue to the origins of life on Earth. While this production is quoted out as a prequel to Alien, and it may well be that this production stands out as a beacon to visual effects artists as yet another level to aspire to. With story references to ‘where did we all come from’, far more than the original, the creation of yawning vistas, damned creepy aliens in full screen, and the most violent, ‘beautific and horrific’ scenes, make this particular piece of eye-candy well worth seeing on the big screen in 3D.
On set, Ridley Scott would constantly refer back to the original Alien film. The approaches the original crew took were very simple in a practical way, and he still shoots in that same way. The moment in that first film when the first face-hugger wraps itself around John Hurt’s face, was captured with very short cuts and bursts of shots. Captured in a way that makes the whole sequence seamless.
The CGSociety interviewed the VFX Supervisors of each major studio working on the movie, as well as the Overall VFX Supervisor Richard Stammers. The challenge was to visualise some of the most intense VFX seen on the screen. This immense job was taken by teams from MPC, Weta Digital, Fuel VFX, as well as fx3x, Prologue, Luma Pictures, Rising Sun Pictures, Hammerhead, Lola Pictures and others.
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Richard Stammers is only just sitting down after seeing the crew screening in late May. Fresh from the job as Overall VFX Supervisor on the Prometheus production, clearly the SciFi ‘must-work-on’ film of our time, he is very excited. “Overall, the shoot was pretty full on,” he says. “There were 1,400 shots in this native 3D movie, all shot on stereo RED Epics, with Atom rigs from Element Technica. Ridley (Scott) likes to run multiple cameras so most set ups utilised at least three of the rigs. “On the bigger action sequences we'd have all five rigs shooting plus an aerial unit that was also shooting stereo. So, yes we were busy,” exclaims Stammers, “Just about every shot in the film had the potential to have some VFX involvement. We were on high alert when we were on set, making sure that we were gathering rig, camera and lens data, to pass onto the of the vfx vendors.”
When we were shooting some of the more complex sequences, the different VFX supervisors from the vendors would also be onset to assist. From Weta Digital for instance, HDR and survey teams were used in addition to Richard's team of data wranglers. “Especially when we were shooting in Iceland, where the exterior and big action scenes were filmed, MPC provided addition support to bolster our production VFX crew. There we had a team of 12 to cover all the cameras, get texture references, HDR's, survey and LIDAR data," explains Stammers. “We were able to get all the lens and rig information and survey the positions of the cameras relative to the environment.”
"When we were out in the field, it came down to keeping close to the shooting crew for each camera, gathering the inter-occular and other rig information. This was all captured onto an SD card on the rig but there was no way to verify the data until the end of each day. So we always had the manual backup of writing the data down as well,” Stammers adds. “In post when we turned over plates to the vendors, each shot came packaged with the metadata from the rig, the lenses, and the cameras. This also included the color information, such as ISO and colour temperature and contrast, that had been set by the DP.”
The Fluent Image company would generate stereo Avid dailies for the editorial team each night. This was colour calibrated to match the look created by the DP on set, so the editorial team could work with colour matched images to what was seen by Ridley while shooting. "When we went to deliver that as the DPX files for the VFX Vendors, they would have this 'look' grade as match clip in addition to the ungraded version of the plate . There were also so many elements for each shot, together with grey balls, chrome balls, green screen elements or smoke, all of those elements would be tagged to a particular shot and would be uploaded as an EDL to Fluent Images web interface and the shots would be rendered from the Red RAW to dpx and pushed to the vendor’s FTP sites. Depending on the speed of the connection, that process could take under an hour," Stammers explains.
MPC used their Kali Destruction pipeline (which is based on the Pixelux DMM Finite-Element System) to handle the spectacular collision sequence where the Prometheus smashes into the Juggernaut ship. The ability to use finite-element simulation to model the physical materials of the ship enabled MPC to create a highly realistic, direct-able destruction sequence.
In sheer magnitude of the VFX work, the bigger sequences were very special indeed. The landing sequence takes the Prometheus spacecraft from orbit, down to the planet surface. MPC was dealing with the whole planet environment. The landing site is visited again and again during the course of the movie.
Within the halls in the alien structure, the crew begins to explore the insides and send out those scanning probes flying down the caverns, to discover and explore ahead. Those scanning probes transmit back to the Prometheus bridge where there is a holotable and this is shown with a very believable miniature 3D LED model generated in real time for those on the bridge. This work was done by Fuel VFX in Sydney. They worked from Lidar scans of the very large set that was used.
“Dave Bowman was the Lead compositor on Hammerpede and Prometheus ship landing shots. Martin Riedel was Lead compositor on storm sequence and Lighting supervisor Daniele Bigi was an absolute guru,” says Charley Henley.
This is one of the first creatures in the movie. It is actually a three foot long snake, with a head that unfurls and appears with a hammer-shaped head like a small shark. Once again, Ridley Scott used a practical model to begin with, in fact on set there was a puppet that could do almost everything that Scott wanted it to do. “The creature department, lead by Neil Scanlon, prepared a number of different versions of this Hammerpede,” explains Stammers. “There was a rubber one on rods, a fully animatronic version, another one which could be puppeteered from underneath the set, capable of swimming and lifting its head. We used the CG version to fill in the gaps in the performance, and where Neal's team reach their limits.” Many events occur in this sequence which I am hesitant to include here. but the jump from prosthetic to CG and back is completely seamless.
The juggernaut crash sequence is towards the end of the film, and is a massive CG build. This involves a crash at close quarters between two launching vehicles and the view was enormous. This ship was built to appear around 750 feet in diameter. "By getting close to it, we could tell that the design of the old ship wasn’t going to hold up to the work we needed to do," explains Stammers. "This redesign was done by a team here and one of the art department concept artists who became VFX Art Director named Steve Messing, and a Russian artist Güterlin who provided some amazing brush work, and this was then handed to MPC to generate in full detail.
The massive peak in the film where the Juggernaut and Prometheus ships collide come about when the crew decide the Earth ship Prometheus has to stop the Juggernaut from leaving the planet and its only solution is to ram it. Down on the planet, two of the team have to run like hell because the Prometheus is falling out of the sky at them.
The production had money set aside to do miniatures for the collision but that wasn’t needed because the CG tools they had at their disposal were good enough to allow it to carry the load, even in this key slow motion shot. Animation Supervisor at MPC Ferran Domenech is singled out for praise for his overall animation and the great postvis work for the Juggernaut crash sequence. “The results are amazing,” says Stammers. “The point of impact and the explosion that follows are fantastic moments.”
The Sty in the Eye
From the gigantic CG moments, down to the macroscopic, MPC's work on Prometheus has it covered. Ridley Scott visits many genres in the movie and this one was pretty creepy. The work was devised to show how one of the ship’s crew has an infestation, the first signs manifesting as a worm that wriggles momentarily in his eyeball, seen in a mirror. This was completely achieved as a 2D effect by Stephen Newbold, a compositor in NUKE at MPC. Newbold created a script which generated a worm effect, and a lot of 2D treatments on top of that to give it the right lighting effect and a wet look. Newbold was also lead compositor on the Juggernaut crash sequence.
The VFX Supervisor and Lead Designer for Fuel VFX, Paul Butterworth worked closely with Ridley Scott and the film’s overall VFX Supervisor Richard Stammers to help realize Ridley’s vision for these important elements in the story, and spent several months in the design and look development process to ensure the final version of the effects met with the director's vision.
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Paul Butterworth had the great job and seemed to have loved every last minute of it. “It’s the kind of job that takes you back to being a kid again,” he says joyfully, filling his time now directing TV commercials. Most of Fuel VFX’s contribution, consisted of the interiors of the LB-41 station which was all shot on set at Pinewood.
The Orrery is the 3D representation of the known universe. A massive gaseous blue model which was loosely based upon a painting that Ridley had, named ‘Philosopher lecturing on the Orrery’ by Joseph Wright of Derby. “Ridley rather liked this as a design, but the Orrery as we see it is lit, as a blue volumetric projection system, depicting the galaxies, clusters of nebulae, supernovae, you name it,” Butterworth said. “As you move thru the display and move a planet into the center of the room, it would expand up to be a closer view of the object. This was a ‘supermatter’ theory of Ridley’s, or ‘frogspawn’ that became known as ‘rings of genetic material’. Each star system could be tapped and would expand to show the planets that were in each star’s orbit. Around that would be shown a diorama of all of the species that existed at various levels of evolution. Well, they could also see Earth, and it could be focused on and expanded as well.”
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Completing the Orrery was the hardest structures to render for any film Butterworth can remember. In some shots there were between 80 and 100 million polygons. “We actually added more data than what was originally recorded in set with the camera,” quips Butterworth. “We started off rendering shots in October, and y’know, we really only finished the sequence in March. So we had to commit early, knowing down the track, once it’s put together, that it was gonna work.” Fuel VFX only really had one go to get it right, before they wouldn’t have had time to complete it. “It was incredibly dense material, and obviously, in stereo it makes it even harder,” he adds.
“One of the things that made it really interesting for us was the use of Deep Image,” explains Butterworth. Combining rendered masses is a short way of describing it. Instead of rendering out flat frames, Deep Imaging allows the rendering out of several clouds of 3D data, and then allows them to be combined in a three dimensional space. The beauty of this is that if a 3D final needs to be modified in stereo, there is no requirement for start again with every layer. “It must be said, Deep Image is incredibly expensive in disk space,” he says. “A single shot may hit the terabyte level.”
Prometheus is one of those films that has dragged movie technology kicking and screaming into the future. Cameras were redeveloped to be used in new and different ways. The RED Epics were there but the number of color pipeline tools were developed especially for this stereo production. Tracking the parallax that needs to be accurate to the measure of a quarter pixel.
The Vicar’s Screen
One whole wall gives way to become a 3D viewing deck. This amazing display could show, as it did in the film, a desert scene or a Swiss mountain forest falling with snow, or it may show the view over an android’s shoulder going into the Juggernaut’s chamber or inside the pyramid or the Pilot’s chamber. “The trick was,” explains Butterworth, “was to make sure it didn’t just look like a small ‘window-sized’ model of the scene constructed. It had to look like a full-scale view of everything it depicted, as it changed.”
Weta Digital worked on over 200 shots in Prometheus
, including the opening sequence with the transformation and destruction of the engineer and his DNA. Martin Hill was the VFX Supervisor for Weta Digital. He talked to CGSociety about the creation of the ‘medpod scene’ with the C-section of the trilobite. There is a scene which depicts an operation being performed on one of the crew, to extricate an alien trilobite from her system. “We had to create perfect 3D match-moves which replicated the stretching of the skin, coupled with some advanced reprojection techniques and some great compositing work,” he says. Stammers puts it in the same category as the ‘chest-burster’ experience of the first Alien film. “Weta Digital again does some astonishing work in there which will have people squirming in their seats,” he says.
The Engineer character in the start of the movie commits ritual suicide by drinking some ‘goo’, which makes his insides dissolve. The process of recreating that effect from the previz and concept required some inventiveness. “Again, this goes back to Ridley Scott wanting to shoot as much as he can, in-camera,” Hill explains.
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“To obtain that level of detail, is quite a challenge. Weta Digital filmed elements that would help ‘drive’ the shaders and effects which would be applied in the CG render. For ‘blood pulsing through the veins’, the crew had slabs of silicon, in which was carved, vein patterned channels. They pumped in blackened oil, water, ink, and backlit it, which gave a natural motion to the effect. We would post-process these elements, and their look would be combined with procedural elements in the shaders,” explains Hill. “The effects would include dramatic bruising, or tightening of the specular where the veins are taut and even show veins bursting under the skin. Similarly we filmed clay cracking, paint drying, which were used later as the skin dries and cracks.”
Weta Digital worked on a prologue sequence where there is an ‘engineer’, based on the space jockey from the original ‘Alien’ film, sacrificing himself in a way that his body is allowed to decay into particles. “This is a pretty cool start to the film before we see any of the human actors,” Richard Stammers points out. “Working with Ridley Scott directly, he always led us down the path where we always had something practical to shoot with. To gather the best performance from his actors it was the best way to go, and then when something extraordinary occurs, we can take over and replace with the CG at a certain point. That methodology stands true on a lot of the sequences we worked on.” The first time we see the ‘engineer’ he is a live action prosthetic.
Weta Digital also worked on about six characters but Stammers says the New Zealand studio does an absolutely perfect transition from the prosthetic to the full CG version of him, including facial close-up, and the detail is brilliant, with his pale, translucent skin. “We’ve captured the silicon translucency and followed it through into full CG,” explains Stammers.
Engineer and Trilobite
The Trilobite is a formidable character, fourteen feet wide, and a match for the nine foot tall Engineer. “As mentioned earlier, Ridley Scott was adamant he wanted to shoot as much as he could in-camera, so he had the actor Ian White, in full prosthetics, basically fighting thin air. Adding a digital character fighting Ian convincingly became a challenge for the Weta Digital crew,” explains Hill. With this, and the actor’s performance, a ballet of moves were devised to make the final confrontation work. “Because the film is stereo and there was such a need for a tight match between the two, we needed a perfect representation of what is happening where on the bodies of both protagonists,” says Hill. Building a 3D set to guide the movement of the many appendages of the Trilobite as well as making sure they matched where the Engineer was at any given movement was a real challenge. “If we moved a leg because the matchmove was out, we'd have to re animated, re solve the creature, re match the shadows. The strobing lighting of the crashed escape pod set made it even more challenging to matchmove the Engineer, as traditional tracking software didn't handle the constantly changing lights well.” adds Hill.
Deacon concept art by Steve Messing
Birth of the Deacon
“We went back to the original Giger drawings and paintings and designs and made sure we could heed those patterns and keep to the design, while modifying it just slightly, enough to get this extra level of articulation,” explains Hill. “The Deacon is the product of the face-hugging Trilobite and the Engineer. What happens next sets up the sequel to the prequel.”