Trevor Hogg chats with Will Reichelt about the visual effects needed to bring extinct species back to life...
“There were two main parts to my responsibilities on Walking With Dinosaurs,” explains Reichelt. “The first was to work with the Directors [Barry Cook and Neil Nightingale], Cinematographer [John Brooks] and on-set filming crew in Alaska and New Zealand to make sure that we were capturing background plates that would be conducive to integrating the dinosaurs into later. It was important to pay attention to the size and speed of the dinosaurs for any given shot so that the camera would be doing the right thing. This was achieved through a combination of pre-visualisation, where we designed basic versions of the shots and sequences, and then on-set using simple life-size practical models of the dinosaurs to replicate what we had done in previs to make sure it was going to work for real. The second phase was back in the studio, making sure that the dinosaurs looked as realistic as possible and integrating them back into the live-action environments. There are also three sequences in the movie that are full-CG, so another large part of the process was making the environments for those sequences feel as detailed and real as the live-action so that everything felt consistent.”
“Besides the skeleton and muscle reconstructions that we used to create all the species and characters, we did a lot of research into modern-day real-world animals in order to find analogous elements that we could incorporate into our creatures,” remarks Will Reichelt. “The theory was that if an audience can relate what they're seeing to animals they already know, then they will buy the strange creature they're looking at as being realistic. This was especially important for the look of the outer skin, scales, feathers and fur. For the Pachyrhinosaurs we looked at rhinoceroses and elephants, and many different types of large lizards such as komodo dragons for the Gorgosaurs.” Reichelt states, “The main surfacing and rendering challenge we faced was the sheer amount of scales and feathers we were trying to render on the characters at any given time. The Troodon has vastly more feathers on it than any character we rendered for our animated film Legend of the Guardians .”
“In the Forest Fire Sequence, all of the fire is either shot in-camera or is a separately-shot practical live-action element; we didn't create any CG fire,” states Will Reichelt. “Because of the scale of the fire, and the fact that we were shooting in amongst real trees, I felt that it would look better if we could have as much of a practical base to the shots as possible. We created most of the other ground interaction effects digitally, using Houdini or proprietary particle systems. We used a fair amount of blue screen [blue as opposed to green, as we were outside in naturally green environments] to capture small elements to put over the dinosaurs feet, or to separate foreground from background elements such as larger rocks, or the ridge of a hill.” Reichelt reveals, “One of the biggest challenges was getting the CG environments featured in the frozen lake and subsequent sequences where Patchi fights Scowler and is trapped in a ditch during the night to look as realistic as the detail-rich live-action environments that had been shot for the rest of the movie. The key to it is layering in passes of detail until the impression of 'messiness' is equivalent.”
The Fusion Camera System developed James Cameron (Avatar) and Vince Pace (Aliens of the Deep) was utilized. “We worked closely with John Brooks, a long-standing and experienced Cameron Pace Group cinematographer to design the 3D for the movie,” states Will Reichelt. “Working with the directors, he worked out the look of the 3D as we were shooting the background plates, and then advised us on the implementation of it in the post-process. We then applied the same methodology to the full-CG sequences to give the whole movie a consistent feel. As well as the technical aspects of 3D, there is also a large creative component to getting it to feel immersive, and to complement the other elements that you're putting into a shot, so it was very valuable to have John and CPG's input.” Reichelt adds, “3D needs to be considered at all stages of the process, it should never be something that just happens at the end of the line. It influences everything from basic staging and layout through to final lighting and integration and can have a strong effect on the emotion of a scene. It does take longer to do 3D well, but it's another useful creative tool in the filmmaker's kit.”
“The sequence that went through the biggest visual transformation was the aurora, where Patchi and Juniper re-join the herd down in the valley,” states Will Reichelt. “That sequence was shot day-for-night, with just a small patch of fake snow in the foreground. We spent a lot of time adding more snow onto the mountains in the background, adding in the night skies, auroras and dynamic shifting light from the aurora down into the environment and then grading a 'frosty' look into the real trees and grass. The final result looks so different so where it began, and I think it's quite successful.” Reflecting on the prehistoric adventure tale, Reichelt observes, “Walking With Dinosaurs was a long journey – three and a half years – and a very rewarding project in many ways. There is so much detail in the creatures that maybe audiences won't notice specifically as they watch the movie, but hopefully it all adds up to a visually-rich experience that will make audiences feel like they're looking at real animals that could have existed. We had a lot of fun making it!”