Mathilde Tollec, VFX Supervisor bei BUF arbeitete an 3 Sequenzen bei „Avatar“. In diesem Interview berichtet Sie über die „Tunnel-Transfer“ Sequenz und den Einsatz von Stereoskopie bei Avatar….
Why have you been chosen at BUF to do the Avatar sequences?
When I arrived at Buf, I worked for one year as a graphic artist on commercials, then on films such as „2046“, „Mon ange“, „Batman Begins“, „Harry Potter and the Goblet of fire“, that how I became a VFX supervisor and onset supervisor on commercials. After that I became a sequence supervisor on films such as „Silent Hill“, „The Prestige“ et „Babylon AD“. And finally in 2009 I was film supervisor and onset supervisor on François Ozon’s “Ricky”. I guess my experience and background were appropriate for the project.
What sequences did you do on Avatar?
Buf took care of 3 sequences on Avatar, the Tunnel Transfers (these are the psychic tunnels Jake and the others use to join their avatar bodies) as well as 2 others sequences at the beginning of the film on earth (that you will see on the director’s cut dvd) on which we did set extensions recreating an overcrowded, over polluted earth.
During the briefing for the shots, how was the stereoscopic effect discussed?
For the tunnels of course, the stereoscopic effect was discussed early as the shots are full cg, but it was obvious for everyone, since the beginning, the tunnels needed to be surrounding the audience. What we proposed to add more interest and dynamic to the shots, is that the tunnel will not be made of one simple tunnel but out of several tunnels with different diameters which gives a great impression of depth and is only visible if you watch the movie in stereo.
On the other hand for shots based on live action like the two earth sequences we did, the stereoscopic effect is decided on the shoot, meaning that the convergence point is chosen while shooting (the choice of the convergence point defined what’s the screen plane, what’s in front of it and what’s beyond it). It’s possible to modify it in post production but the real challenge in working on a live action stereoscopic vfx shot is to match the 3d space of the cg perfectly on the shot 3d space. The matchmoving need to be perfect.
Was Avatar your first project dealing with stereoscopy?
Yes but it wasn’t the first project in Buf as the company has already dealt with stereo on an animated film. But working in stereo in full cg is much more simple than dealing with live action shots were the cg stereo as to match the shot stereo, plus you don’t have to do all the treatments required on the plates to match perfectly the two eyes.
Fortunately Cameron’s team made sure to explain us all the stereo techniques and the problems inherent to stereo were explained to all the vendors. Chuck Comisky the stereo supervisor was always very precise.
What are the new requirements for doing stereoscopy, in terms of Hardware, Software-Pipeline and artistic approach?
Of course, stereo requires more rendering power as you need to render twice all the images. The pipeline has to very flexible and organised as images from both eyes need to go through the exact same process. You need to privilege 3d over comp as traditionnal 2d tricks won’t work in the stereo space.
The artistic approach is about the same as in 2d. As you watch your shots in stereo, you naturally tend to create interesting volumes without really talking about it.
Watching the final results, Do you think the stereoscopy enriched the Movie, and/or will enrich the world of VFX?
Yes of course, the steoroscopy really brings another dimension to films, even when it’s not obvious it really emerges more into the film’s word. The more you watch stereo, the more you appreciate it and enjoy all its subtilities, I wasn’t convinced by this technique when I started this project, now I’m huge fan of it.
Even if it’s harder and it demands much more work, working in stereo is really great, it gives cg its real dimension, the audience can see the real volume of the modeling, the details of the textures and shaders, the animation in a real 3d space, the particles as if they were coming out of the screen…
What is the next project/film you will work on?
I can’t really talk about it right now as I’m under NDA.
Thank you Mathilde for the Interview!
Images copyright Twentieth Century Fox