Ice Fight
Barbara Robertson
February 10, 2015

Ice Fight

Put a nine-foot-tall giant and a dwarf on a floating sheet of ice. Have them fight as the ice moves toward a waterfall. Easy? Not so much. Actor Manu Bennett played Azog the giant Orc and Richard Armitage played Thorin, the dwarf.

“I spent a huge amount of time on the fight between Azog and Thorin at the end of the film,” says Aaron Gilman, animation supervisor. “The performances are on a moving surface. Azog is swinging a block and chain, which has its own weight. We had to make performances that sold the believability of the fight itself and the believability of the floating ice over dozens of shots.”

To choreograph the fight, the team started with the ice. 

“We mapped out every piece of ice that gets smacked off during the sequence,” Gilman says. “Then we mapped its position from one end of the lake to the other – where it is, how big it is, and how many pieces have broken off.”

Next, the crew built a large, moveable wooden platform that roughly matched the size of the ice sheet. 

“We had the actors perform on the platform,” Gilman says. “When their weight shifted, the platform shifted so they had to counter their balance. It was important to the motion capture that we got an inherent sense of slipping. So, in some instances, we gave them a mock roller skate with ball bearings built into the bottom so a performer could roll a foot. He would be stable, but would slip enough to buckle his hips.”

The obvious challenge was the size difference. 

“Richard [Armitage, who plays the dwarf] is six feet three inches or six feet four inches,” says Eric Saindon, visual effects supervisor. And Manu [Bennett, who plays Azog] is taller, but not nearly tall enough to look realistic. So we captured general motion from them and did a motion-capture session later.”

The second challenge was in getting a proper weight for the block and chain.

“When we started the sequence, we gave Manu [Bennett] a block and chain with five kilograms on the block, but it was clear that we were going to hurt him,” Gilman says. “I can’t tell you how heavy that feels when you try to swing it. So, depending on the action, we had four different weights of block and chain. We’d use whatever block and chain was appropriate at that moment.”

For an in-depth look at the creation of this visual effects in this film, see "Fight to the Finish" in the January/February 2015 issue of CGW.

Barbara Robertson is an award-winning writer and a contributing editor for Computer Graphics World . She can be reached at .