Inside Pandora

Nolan Murtha,Digital Effects Supervisor,Lightstorm Entertainment and Shawn Dunn,Head of Layout and Animation Technologies,Weta Digital discussed how various technologies were used to bring James Cameron8217;s vision for Avatar to life. Lightstorm Entertainment is owned by James Cameron.

The making of Avatar is a compelling story in itself. Cameron conceived the film around 1994 and spent nearly a decade looking for technology to get up to speed with his vision. The moment finally came with the release of Peter Jackson8217;s The Two Towers and New Zealand based Weta Digitals work on Gollum,the slimy human creature played by Andy Serkis. From then on,technology simply bounced ahead with complex sequences from The Matrix and animation technology from Robert Zemeckis8217; The Polar Express 2004 that used Tom Hanks face as the reference point for its lead character. Zemeckis used the same technology once again in Beowulf in 2007,with Angelina Jolie and Ray Winstone in title roles who were filmed on a motion capture stage and altered on screen using computer generated imagery CGI. As Murtha says,The viewer has to feel emotionally connected to the character. Gollum first showed what CGI could achieve and made the whole sequence legitimate.

But,even after all their gargantuan efforts,the team was skeptical about Avatar8217;s success. The story played out between 10 feet long blue aliens within a jungle that glowed in the dark. It could have been a recipe for disaster, Murtha says straightfaced.

The movie itself used a lot of special technology that opened up a whole new stream of avenues for filmmakers. Creating the world of Avatar was incredibly time-consuming and a job that was never over until the film was ready for release. Murtha explains,To give a comparison,Gollum never changes his clothes,but Neytiri Zoe Saldana went through 10 costume changes. Describing another difficult scene,Murtha says that destroying the Tree of Life in Pandora,around which the lives of Na8217;vi8217;s revolve,took six months to create.

The scene where Neytiri pushes her head towards Jake Sam Worthington and kisses him in the glowing jungle lasts for all of three seconds but it took months to create. The scene was also complicated by the fact that the actors had to wear a headgear while shooting. The gear comprised of four high-definition HD cameras that tracked the facial movements of every actor in detail. When the actors came close together,the head gears would collide and had to be worked around in a different way than the rest of the film. The information from the cameras was then super-imposed on the CG character of the actors. This type of shooting is called Real-Time performance capture and has been used effectively in movies like The Polar Express with Tom Hanks and Beowulf with Angelina Jolie.

As the duo state,the talent and creativity of the actor is critical to driving believable performance from the CG character. Technology is no substitute for personality and the human element is essential to creating engaging digital characters. Thus,it is through the advanced combination of body,facial and vocal performance capture technologies that the craft of the actor is integrated into the Virtual Moviemaking pipeline in a way as effectively created as in Avatar.

The most difficult thing during face capture is that it has to look like the character and that can get tricky. Once you put the markers on the face and try to convert them into polygons,there is a huge amount of work that goes into that, Dunn explains,adding that his team had a great facial animation team that helped to bring out the expressions of the actors accurately during post production.

The team at Lightstorm and Weta used a complicated procedure called Virtual Cinematography that uses virtual cameras to create Pandora and its inhabitants. Virtual Camera is like taking a monitor off the computer. We use our best motion building software like within the camera. The virtual camera has several controls; you can zoom in and out and create a virtual simulated space. Cameron could shoot with the actors without having to be right next to them. He could move himself in the 3D space as well as move up and down, Murtha says.

Cameron8217;s world was so immersive that even the creatures were made entirely out of the director8217;s imagination. This meant that they could achieve impossible speeds and maneuvers. The animators looked at fierce creatures such as cheetahs,lions and horses to create most of the animals in Pandora. The most used creatures in the movie were the flying banshees,inspiration for which came from the flight patterns of falcons and swifts.

Juxtaposing these creatures with the actors was the next step. To record the motion path,the makers made miniature gunships and banshee puppets and moved them around tiny mountain puppets. They would then put the motion of a human flapping his arms on the wings. The team recorded the flying path and then put up the monitor in front of the actors face who would look into the monitor and act as the banshee by flapping his arms hard and bringing out his chest if the banshee was flying up. He would have to mime ducking low if the banshee was flying down. We had an acrobat who would run around on the floor. We would improvise a few things but we used a human to give motion to the CG animal mostly just to get the speed,the tempo and the time, Murtha recalls.

Looking at the script and going through the breakdowns,Lightstorm had to figure out how many CG environments would need to be created along with the environment,number of creatures and the actors. The fact that the movie was being made in 3D didn8217;t help matters. After going through the motion capturing phase,they would go through an editorial phase. The editors would sit with Cameron and would select between two to 27 takes for each shot. Dressing the environment took two days. We had to figure out which tree goes where,where every animal is placed in every scene and how the characters were interacting in the scene, Murtha reveals.

Compositing scenes also turned out to be much tougher than expected. Add to that Cameron8217;s quest for perfection and it was a recipe for disaster. For the home tree,Cameron said it had to be horizontally slanted but vertically straight. How do you design something like that? Murtha asks,incredulous. He also said that with Cameron,you don8217;t have shots but scenes. Every conventional shot becomes 10 to 15 scenes with him.

To create the 3D effect,the team used three cameras that were put together to create a single stereoscopic image. They would open the same file on two computers and render the right eye on one computer and left eye on the other computer while an operator would sit and control the other two computers from the third camera. For every single shot in the movie,we literally went frame by frame to evaluate the 3D stereo effect, Murtha says.

Cameron would also shoot scenes from 15 to 20 different angles. So if he wants a hand to come and touch the home tree,he would shoot from different angles. When we looked at it in the final environment it needed to be closer to the frame. Digitally its very easy because in the virtual world you can move things without disturbing too many things. In the final environment world,doing the same sequence is quite painful. For example,in the scene when the gunship is hovering above the forest and looking down at the home tree,Jim Cameron wanted to show the ground,but if you notice the home tree is tilted. We had to create another home tree which was straighter for that shot so you can see the ground from the gunship hovering above, Murtha explains. To achieve all of the above,the makers used a range of softwares to guide them to their aim,primary among them being Autodesk8217;s Motion Builder software.

Avatar8217;s work was spread all across the globe and coordinating all the schedules,managing the time difference and getting the work done on time was one of the challenges as well. From San Francisco London to Paris to Montreal to Weta in New Zealand,that was quite a task. And the stakes have only gone up with Cameron8217;s upcoming sequels Avatar 2 and Avatar 3 slated to hit screens in December 2013 and 2014 respectively. Dunn is already sweating from the prospect. Weta took 100 million render hours to work on Avatar. The hard disk capacity touched 2500 TB terabytes in the end. We8217;re now making the films in 4K standard which means 16 times the original render hours. Avatar took 250 days of motion capture and 500 days of production in comparison to Titanic which took only 180 production days, he rattles off.

Both Murtha and Dunn say they are stunned with the positive response for the film from across the globe. The duo credit the success of Avatar entirely to Cameron. As Murtha says,half in awe,It tells you a lot about him when even your best is not good enough for him sometimes.