Issue link: https://digital.copcomm.com/i/110653
n n n n Environments•VFX At top, the Rivendell set on the greenscreen stage behind actors Cate Blanchett and Ian McKellen has a tiny waterfall, but most of the waterfalls were digital. At bottom, Weta Digital artists replaced the greenscreen with a digital environment and extended the set. The crew did not film any miniatures. location for Bilbo's first meeting with Gollum. On set were actors Andy Serkis [Gollum] in a full performance-capture suit with facial capture rig, and Martin Freeman [Bilbo]. "We did the captures down the street in a massive warehouse," Capogreco says. "Gollum's rock, where he dragged the goblin out to eat it, was completely CG. Anything beyond that finger-like rock was 100 percent CG. The walls and the main area where Bilbo and Gollum riddle, and the rock you see Gollum come over, were built on set, but everything behind a meter or two in any direction was digital. Some shots were all-CG because it was easier." In postproduction, the artists removed Serkis from the plates, rebuilt the environment behind him, and inserted the digital Gollum. "Each of the 200 shots needed a level of paint work," Capogreco says. "We had clean plates we could use to help the paint artists. They also projected stills onto Lidar scans. But, we're talking 48 fps and stereo. We had to paint, and paint in depth." Rivendell Above ground, the action takes place in rolling hills, stony mountains, and the beautiful Rivendell, which was a major location in the Rings trilogy. "We did all the wide shots and 10 set extensions in CG, but we wanted Rivendell to be recognizable as the same location in The Lord of the Rings," says Aitken. "We looked at the photographs of the miniatures shot for Rings. And, we had Alan Lee and John Howe back. As soon as they wrapped up on the shoot, they moved over to [Weta Digital] and became our in-house art department. We relied on their in-depth knowledge of what Middle-earth looks like." On set, Gandalf, Bilbo, and the elves moved through elegant Rivendell interiors built on set. But, the most dramatic element in Rivendell is the water flowing through the city and streaming down in waterfalls. "We built libraries of simulated waterfalls," White says. "We realized we could use the city waterfalls in the surrounding environment and the compositors could place them in the backgrounds." To create the water, the crew used the studio's in-house simulation tool called Synapse. "We did a lot of work on Synapse for Tintin and then refined it for The Hobbit," Aitken says. "The water was pretty much all-CG. When the company first comes into Rivendell on their horses, the waterfalls in the distance and the water flowing around them and under the bridges are all-CG. The [effects team] did mul- tiple simulations for the body of the water, and often several simulations generated separately worked together to create these water events. It had to look beautiful. This is where Bilbo will want to spend the last years of his life." Water much more chaotic than the calm waters of Rivendell also played a part in the Misty Mountains where the dwarves found themselves in the middle of a battle between stone giants. "It was a big dynamics effects sequence," White says. "With lots of rigid-body dynamics, rain, lightning, volumetrics, atmospherics, and digital doubles of the dwarves riding on the legs of stone giants. It was at night, and Peter wanted dark, strange shapes that looked like creatures of the mountains silhouetted against the sky." Effects crews sent fluid simulations of rain, mist in the air, and mist flying off digital rocks. Those rocks, tossed by CG stone giants, fell, hit other rocks, and broke apart with motion created through rigid-body dynamics. Weta's Synapse also played a part in a sequence in which three trolls tied several dwarves to a spit in an attempt to roast them over a fire. The trolls were CG with animation based on performance capture. The dwarves were real. The fire was CG. "We wrote a new effects plug-in for [Side Effects'] Houdini for the fire, which is handled within the Synapse framework," Capogreco says. Growing a Forest After Bilbo and the dwarves leave the trolls, they encounter the wizard Radagast, who helps them escape from Orcs and the wolf-like Wargs (see "Of Gollum and Wargs and Goblins, Oh My! on page 14) by leading the attackers on a merry chase in his rabbit-drawn sleigh. Radagast is real. The sleigh and rabbits are keyframed. "We had a sled towed by an all-terrain vehicle," Aitken explains. "But as we extended the forest and replaced the greenscreen set with a wider forest, it became easier to replace the trees on set with digital versions. To create the trees, modelers used an in-house tree-building program called Lumberjack developed specifically for this film. "We had two problems on Hobbit," Revelant says. "One was to create nice-looking trees quickly. The other, more complex problem was to extend the trees already built on set. We couldn't create a fully procedural system because it wouldn't allow us to exactly match what they had built." Instead, they developed a procedural software program that artists could control with an artist-driven modeling tool for drawing curves and generating geometry, and a growth-based procedural tool for adding branches and leaves. January/February 2013 CGW0113-Hobbit1pfin.indd 10 1/31/13 5:15 PM