DIRECTOR : James Cameron
PRODUCTION : 20th Century Fox
VFX SUPERVISOR : Mathilde Tollec
VFX PRODUCER : Alain Lalanne
MAKING OF : Jérôme Pesnel
MUSIC : Alexandre Desplat - La Sortie
NUMBER OF SHOTS : 2
“An epic film born entirely of Cameron’s imagination, Avatar uses tailor-made technology to create the most astonishing visual effects yet seen on screen and blends them seamlessly into a mythical sci-fi story about an ancient alien civilization fighting the encroaching human menace. It’s an unprecedented marriage of technology and storytelling which is on the whole remarkably successful.”
- Screen International
When his twin brother is killed, disabled ex-Marine Jake Sully is recruited to aid a mining expedition on the distant jungle moon of Pandora as only his DNA will bond with the alien hybrid body, known as an Avatar, that allows humans to breathe the toxic air. With orders to infiltrate the Na’vi, Jake finds himself falling in love with native girl, Neytiri, and complications soon ensue…
BUF's work consisted of researching the perfect design and dynamics for the mental transfer of a human being leaving his body to incarnate his Avatar. The shots were to be delivered in stereo, and needed to envelop the audience as they travel through the tunnel with the characters so allot of effort was put into layering tunnels of different diameters. These layers consist of many different elements, some are made of organic materials such as networks of neurons or veins, others were pictured as energy fluxes such as rings and rays of light or flashes of lightning. The main challenge was to make the images legible despite the very high speed of the camera move, and the motion blur involved.
The various tunnels were set up independently, computed according to the trajectory chosen for the camera, then composited together. Lights were automatically generated to precede the camera through the tunnel in order to light the end of the tunnel, and give the impression to the audience that they are following the light.
The Earth Shots (one shot for the Pedestrian Crossing and 13 for the Alley) were Set Extensions that were designed specifically for 3D screening. Only the foreground was actually shot - against green screen. BUF created and integrated the background set according to the references provided by the production, adapting them to the filmed shots (aerial train, holographic commercials and surrounding buildings).
For this scene, only two medium close passes of the crowd were shot. The only visible part of the set includes the street in the foreground and the changing of the traffic light. To simulate the strip lighting, the extras were lit by blinking colored lights.
Taking into account the initial camera move on the foreground crowd plates, the shot features a wide introductory view on the crowded futuristic city. Because the stereoscopic view is more demanding than in 2D films, the depth and placement of the buildings has to be very precise and coherent. Once the main buildings were placed and the overall architecture defined, the crowd was created, thus matching the live takes and perfectly integrating them into the 3D environment ambiance.
BUF's Art Department, led by Olivier Gilbert, also designed the holographic commercials (the “Media Sky") and billboards that populate the city. For the Full-CG commercials, we shot a few characters to integrate them in the designs of the ads. All of the Mediasky was developed with the stereo in mind, accentuating the impression of depth by enhancing the parallax between them. This is why some commercials might seem very flat if seen in 2D, while in 3D they show much more depth.
These two Earth sequences have trains that run through them. Each train was modeled and textured independently then filled with 3D extras. Next, each train was animated, lit and integrated into the shots. Due to the very bright and busy environment with heavy strip lighting and commercials, the lighting and placement of reflections were crucial to achieving realism. Additionally, the placement of the raised train tracks and their supports as well as the skyscrapers had to be very precise to ensure that the depth would be realistic when projected in stereo.
Finally, we created the Laser Pedestrian Crossing. The challenge here was that director Cameron wanted the crosswalk be floating six inches above the ground. This meant that all of legs of the characters would cross through it. This work was quite complex as we had to match-move the live characters in stereo to ensure that the interaction between the Laser Crossing and the legs would work.
Only the foreground of the set was shot live (the entry to the alley, back door and actors) were shot. The rest of the shot is Full CG. To achieve the best results for set extension, careful attention was paid to maintain the continuity between the filmed foreground and the CG set background. The architecture, the wet reflective materials such as walls, the ground, pipes, the blinking lights and the ground full of puddles we created had to match the live plates for shape and texture. Reflections in this very humid, dark environment also required great attention to detail. We had to ensure that the waves in the puddles would distort the reflections of the commercials in a natural manner and appear correctly in stereo. Haze and mist were also added to recreate the dark and humid atmosphere of the sequence, all in stereo. From the three points of views of the sequence, the most dramatic features are the trains and the Mediasky. It was very important to place the commercials and light the set to match the lighting on the actors. Since the shots were filmed against green screen, the resulting images were very green so quite a bit of color-correction was required to restore the actual color of the alley.
In addition, the continuity between live action and CG had to work for all points of view. Since these shots show a lot of depth, the camera calibration required a lot of precision because even a tiny difference in the spacing between the two cameras could result in a huge difference in depth perception.