- Double Negative: Tracking The Hunger Games with 3DE4
Who are you and what is your position at Double Negative? PUJA PARIKH: I am Global Head of RPM at Dneg. DINESH BISHNOI: I'm Dinesh Bishnoi, a Matchmove supervisor at Double Negative. MICHAEL KARP: I'm Michael Karp, also a Matchmove supervisor at Double Negative. Can you give a brief summary of your career and outstanding projects you have been working on? PUJA PARIKH: Started my career in vfx as systems and pipeline with R&H in LA in 2003, after which moved in matchmove, body tracking and tech anim. In 2006 end moved to MPC, started as an TD and slowly moved up the chain as a Global HOD for Matchmove and Rotoanim. In 2016 dec, started my journey with dneg. Have worked on lots of interesting and oscar winning projects like Happy Feet, Golden Compass, Life of Pie and Jungle Book. DINESH BISHNOI: I started as a Matchmover in MPC 2009. I have worked on many big films, Life of Pie, Prometheus, Batman v Superman:Dawn of Justice, 300:Rise of an Empire, X-Men, Fast & Furious - 8, and Terminator - 5. MICHAEL KARP: I began as a visual effects, stop motion and motion control cameraman in 1983. In 2000 I switched into Matchmove and Layout, at Digital Domain. I have worked on films that include X-Men - 1, X-Men 2, Wolverine, X-Men FC, Harry Potter, Alice In Wonderland - 3D, Fast & Furious - 7, Great Gatsby, Terminator - 2 and Terminator 2 - 3D, plus working on Titanic and with Michael Jackson on his featurette Ghosts.
Hunger Games was entirely shot 35mm Arriflex spherical, but Mockingjay 1 & 2 were filmed with the more difficult anamorphic format (using digital Alexas) and contained large numbers of crowd replacement, CG sky and set replacement extension shots.
These shots were difficult because of the long frame ranges and because the Hummer vehicles were moved after the LIDAR scan was complete. The 2D tracks were challenging because of the smoke and lighting flares.
Digital still camera on set photos were very helpful as reference frames for the 3DE solver. The vital continuity of line-up was maintained between many shots in the sequence.
When did you first get in touch or use 3DEqualizer? PUJA PARIKH: It was in 2006 end, I was introduced to 3de when I joint MPC. At first was a bit reluctant, as was use to voodo which is a proprietary created by R&H. Missed a few tools in the start,slowly and steadily realised that 3de can achieve the same and is open to our inputs and keeps updating the software to have the best results to help the vfx industry in the field of camera tracking. Its a very user friendly software and have amazing tutorials on how to use the software and also about the new releases. DINESH BISHNOI: I started using 3de at MPC. Initially I was not familiar with the features so it was not comfortable for me directly jump on to 3dequalizer for every shot. As we know 3DE is sort of hard to learn, but it is easy to use. Once I learned the software it became very fun to track with. The whole system is sophisticated and well thought out, so it reduces labour and increases productivity. MICHAEL KARP: In 1996 I met Rolf Schneider (from 3DE) at a presentation of competing Matchmove softwares at Silicon Studios in Santa Monica. His technical approach to camera tracking was so different than everyone else's. And then in 1999 I attended a live presentation on the making of the documentary Walking With Dinosaurs. The effects supervisor said that it was very easy to track the plates, which shocked me because our older (but still revolutionary) surveyed solver software was much more brute force labor intensive than the surveyless 3DE software. Can you give a brief overview for which tasks 3DEqualizer is usually being used at Double Negative? DINESH BISHNOI: 3DE is used for almost all of our work, for 3D camera and rigid object tracks and for 2D tracks to assist rotomation body tracking. How many artist use 3DEqualizer on a daily basis? DINESH BISHNOI: We probably have around 170 Matchmove artists divided between our Mumbai, Vancouver and London offices. How many different projects is your match moving team usually working on at the same time? MICHAEL KARP: We have around ten to fifteen big Matchmove shows going simultaneously. How many shots, tracked with 3DEqualizer, are roughly being published/delivered on an average day?
DINESH BISHNOI: We deliver around 35 complex tracks per day.
Shot continuity between tracks was very important on this crowd replacement sequence. Notice the heavy barrel distortion on the wide angle anamorphic plate, while the longer focal length lens has a more rectilinear distortion.
What were the specific challenges of tracking Mockingjay? DINESH BISHNOI: On the Mockingjay shows it was a big achievement for my team and I to learn how to handle complex anamorphic shows. Lots of anamorphic focus breathing was the big problem. Anamorphic lenses are nasty to track, because the pixel aspect ratio of the images varies asymmetrically during focusing. This means that the anamorphic zooming effect is different vertically and horizontally. Also, the CMOS sensors of Red and Alexa cameras still exhibit a small amount of rolling shutter skewing and this must be corrected, for high quality solves. Some of the time we didn't received LIDAR from the client, so without the LIDAR or some type of set survey/measurement it is hard to achieve a perfect camera, but the Push Point tool, multiple angle survey and utilizing the reference images helps a lot to get cameras tracked with high quality. How did your team solve those challenges with the help of 3DEqualizer? MICHAEL KARP: 3DE has powerful tools to deal with anamorphic and Rolling Shutter. There are a few approaches to solving anamorphic. We tend to use the "Eric Method", which is named after Tracking Layout supervisor Eric Gambini. Several people have independently come up with this technique besides Eric, but he championed this method early on. Basically, when determining the distortion and squeeze x/y for a plate, you do a parameter adjustment, with LIDAR, with the Calc Range set for a single frame. Then you repeat this calculation every ten frames or so and build up an animation of changing lens distortion and x/y squeeze in the 3DE curve editor. The "Eric Method" superficially appears to be a little low tech and inelegant, but it actually works very well in a practical sense, for delivering shots without too much hassle. Anamorphic tracking is always painful, but the Eric Method of using the great 3DE tools gets solid results.
The Toxic Oil sequence tracks needed to be very tightly matched across the entire LIDAR and plate. We also created a body track for a character engulfed by CGI Toxic Oil. We were not using Rolling Shutter correction for the Alexa at that time, but it really would have helped. Rolling Shutter correction is now a standard part of the tracking pipeline.
What specific features of 3DEqualizer separates it from other products? DINESH BISHNOI: The handling of difficult anamorphic shots is very powerful, especially with the animated squeeze x/y. The 3DE Rolling Shutter pipeline is robust. And of course the line-up functions for LIDAR are wonderful, very easy to use. Are there any other specific reasons why Double Negative is using 3DEqualizer? MICHAEL KARP & PUJA PARIKH: 3D Equalizer is site licensed at most of the large tracking facilities in the world. The slightly steep learning curve is richly rewarded in ultimate ease of use. The Lineup functions for LIDAR are very powerful and the handling of animated anamorphic distortion and rolling shutter are very advanced. When you have thousands of camera and body tracks to deliver in a year, a proven and usable tool is needed. Also, the customer support from 3DE is superb, most issues are fully addressed the same day.