The Hobbit: The Desolation of Smaug saw some of the best special effects to date. If you haven’t seen it be warned, this will have spoilers. That said, the scene where Smaug chases Bilbo about the mountain of treasure is jaw-dropping and obviously took a lot of work. Yet the barrel escape scene seems more straight forward. That intricate blend of 4K footage and GoPro shots is thanks to Weta.

Weta Digital’s VFX supervisor and four-time Oscar winner Joe Letteri told The Hollywood Reporter that Smaug was the biggest challenge, literally. "He’s huge, twice as big as a 747." 

Peter Jackson, the director, had wanted Smaug's physical size to dominate, he said. "Then we had to figure out how to build the environment around him, so he had the room to move. It was like the size of Monaco."

Then there were the gold coins, constantly moving as the dragon and Bilbo did. "We had to simulate all the gold coins, every time he moved," Letteri said, noting that Weta wrote new software just for that. "Sometimes it was a little, sometimes it was a lot, but it ended up being over a billion [CG] gold coins. During some of the action sequences, there were hundreds of millions of coins moving at once."

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But it wasn’t just large-scale feats that made the film impressive. It was also the seamless transition from scene to scene and location to location. Jackson even used GoPro action cameras to shoot part of the barrel river escape. That’s a jump from full-sized cinema cameras to something you can fit in your pocket. While it is possible to spot this it has been done in such a way that it really works.

the new hobbit movie saw weta digital make smaug larger than a 747 in one scene yet use gopros in another image 2

"We couldn’t shoot a lot of what we needed to do," Letteri said. "We found bits of river that we could use, and did some of it [live action] in a waterway that we built, but a lot of that action had to be created digitally - the water, the characters, the environment. For the more frenetic stuff we threw barrels in the water and would put digital doubles in them."

Weta said on its Twitter feed: "There was some GoPro footage. We cleaned it up in Paint, in one case added a CG dwarf and post converted the shots to stereo." This kind of versatility is what makes Weta Digital one of the best VFX studios. And another reason we’re going back to the cinema to watch The Desolation of Smaug again with a new level of digital appreciation.