Awesome article from The art of vfx and Vincent Frei with Jacob Otterström, Vfx Supervisor at Filmgate and their work on Centurion.
What is your background?
I’ve been experimenting with all sorts of computer related stuff since I got my Commodore 128 when I was nine years old. As a teenager I tried out everything from sound editing, programming, retouching images in Photoshop to 3D Studio For DOS and so on. When I studied Civil Engineering, Media Technology, in 2000, I discovered the joy of 3D graphics added to filmed material. I left school and found another education in computer graphics in the north of Sweden called gsCept. There I met an old friend from my previous schhool, Fredrik Averpil, who later co-founded Filmgate and brought me on as well when I finished my education.
How did Filmgate get involved on CENTURION?
Filmgate had developed a long relationship with the producers starting from our first production EDEN LAKE.
How was your collaboration with director Neil Marshall?
We were very keen to work with Neil after his work on THE DESCENT and we felt very lucky to have collaborated with him on CENTURION. He allowed the vfx artists to develop ideas and encouraged them to be creative. He was also very understanding of the vfx process and showed great patience as well willingness to compromise when necessary. He was basically a joy to work with, even taking his pathological love for blood into consideration (laughs).
Can you tell us what you did on the shot where we see the hero runs in the snow?
The shot was not planned as a vfx-shot. We were given two plates shot from a helicopter, one showing a snowy mountain top and one where we pass over the actor running on a grassy hill. The objective was then to get the actor to run in the snow plate instead. I started out 3d-tracking both plates, making sure that we would get good results when we later were to place stuff in the snow. Having done that I turned to the plate with the running actor, stabilising the plate first based on the 3d track, then in 2d, centered around the actor. After some rotoing and tweaking I was able to
isolate a sequence of frames and get a more or less complete running cycle. A few grid and spline warps were then applied to make it completely seamless.
The running actor was then moved to the snow plate and placed on a card in Nuke’s 3d space together with some tracks in the snow behind him. Finally, some layers of snow blowing through the air was added to the 3d scene making sure the shot cut properly with the following scene where the actor runs in snow for real.
What was the size of the real set for the camp of the 9th legion? What have you done on this shot?
The size of the real set was not much more than 25×25 meters (83 ft.), but with tents, wagons and other set pieces cleverly placed so that we could extend the set without using green screens. We ended up extending the set with more tents all the way to the horizon, replacing the sky and adding life to the camp by placing camp fires, smoke pillars, moving flags, people shot against green screen, flying birds etc. through the whole scene.
Can you explain what you have done on the sequence of the attack in the forest?
The main shots here for us were of course the shots were you see the roman legion coming down a narrow road towards the camera with steep hills on both sides. Our work here was mainly two things; duplicating the army from 30 extras to a legion of 3000 (even though you don?t see all of them , at least 250 would be visible in these shots) and also comp in and duplicate the fire balls coming down through forest. We did this simply by simply shoot a plate with the soldiers way back, put a marker on the ground, moved them closer to camera, shot a new plate and so on.
We had about three real fire balls on set and even though trenches and slopes were created for them to roll in, they were unpredictable and difficult to control – some of them would just stop half way down, or not come down at all. Also, bringing them back up and re-ignite them took some time, so to speed things up we decided before shooting to place an opposing camera at the end of the road on which we were shooting and just mirror that plate in post. We later enhanced the fire balls coming down by adding more fire elements, light effetcts on the trees as the balls passed and fog and smoke. When it comes to the man to man combat scenes and the impacts of the fire balls, most of it was done in camera, but we added blood, replaced some faces and animated flying arrows and axes (and cut some heads off).
Did you do something on the shot with the corpses on the road after the attack of the forest?
While the team ws shooting other shots in this sequence I took the opportunity to take photos of extras dressed as Roman soldiers and Picts lying dead on the ground – strewn around and piled up on top of each other.
As you can see there were only dead bodies lying on the road in this shot, but Neil really wanted them to cover the whole hill all the way up to the camera. The way we achieved this was to isolate all the bodies from the photos I took on set, grabbed a single frame from the middle of the shot and then started placing them all over the area in Photoshop. Since this was quite a long crane shot and we needed bodies lying close to the camera we couldn’t just place the bodies on cards in 3d space. After having scattered all the bodies in Photoshop we then turned to Maya and created a mesh to project our painted bodies onto, which was more detailed the closer we got to the camera. In this way we could have hundreds of bodies spread and get the parallax we were aiming for out but still have a Maya scene which was really basic and with a fairly low poly count.
To add to the realism we also added some grass by creating patches of Paint Effects on which we projected the original plate, so we needn’t worry toget the look exactly right. The grass in it self doesn’t lokk very good, but having patches of it sticking up between the bodies really made a big difference. With all the bodies in place we started adding more elements; a dead horse, patches of fire from the rolling fire balls, smoke, fog, embers and replaced the background with Scottish mountains.
The film is quite bloody. Were you involved on on this aspect of the movie to increase the impact, injuries and the amount of blood?
In short – at almost any point in the movie where there’s an impact from a weapon (or a fist) we’ve been there, adding blood, enhancing it or tweaking it in some way. We also added blood squirting and hitting objects such as tents and shields and added sparks from swords hitting chainmail.
At one point, the characters are faced with wolves. How did you makes those shots?
From the start director Neil Marshall said he wanted to use real wolves for the wolf chase, which turned out really good. A small team filmed a ”tame” wolf against a green screen. Directing the wolf was of course difficult, but we got a lot of material and were able to get what we needed for most of the shots. However, one of the shots was a long helicopter shot where we fly over the Scottish landscape with the actors running beneath us. In this shot a flock of wolves are supposed to appear from different areas of the frame and homing in on the running men. We clearly couldn’t accomplish this with a green screen shoot. We therefore ended up creating a wolf in 3d with fur matching the real one as well. The 3d wolf even turned out to be good enough to be used together with the green screen material for some of the other shots.
Have you created matte-paintings?
Our matte-painter Linus Lindbalk created around 15 full-scale matte paintings for various types of shots such as set extensions, environment and sky replacements etc.
How did you create the Hadrian’s Wall and what references did you have?
We got a lot of references from the art department and from Neil – I think he did quite a lot of research for this movie. Based on those references the art department created a small section of the wall with a gate on location. We were then able to shoot lots of reference images for the look of the wall and we could just extend it any way Neil wanted. The scene was shot in the countryside south of London, so most of the landscape was replaced with a matte painting to get the feel of the area around Hadrian’s Wall with its characteristic hills. On and around the wall we placed guards and slaves shot against green screen and cg scaffolding since the wall at this time was a work in progress.
What is your pipeline and your softwares at FilmGate?
Our main software and ”hub” is Nuke from The Foundry, but we also use Autodesk Maya, Adobe Photoshop, Syntheyes from Andersson Tehnologies and FileMaker.
How many shots have you done and what was the size of your team?
We worked on around 250-260 shots with a team of 10 for about 7 months.
What is your next project?
We have a lot of International productions on the go just now DECOY BRIDE (UK), THE WOMAN IN BLACK (UK/US) , THE LAST FURLONG (IRL/FR/SWE), CROWN JEWELS (SWE) and possibly MELANCHOLIA.
What are the four films that gave you the passion for cinema?
STAR WARS, THE EMPIRE STRIKES BACK, NEVERENDING STORY and a reawakening with THE MATRIX.
A big thanks for your time.
// WANT TO KNOW MORE?
– Filmgate: CENTURION page on Filmgate’s website.