The third and final installment of the Hobbit trilogy will end with a big bang in a 45-minute battle scene, director Peter Jackson has revealed to Entertainment Weekly.

He said the climactic scene will take place at the foot of the Lonely Mountain as various armies fight for the newly reacquired dwarven treasure of Erebor.

He was quoted as saying: "There's a lot of logistics that have to be thought through. We have dwarves and men and elves and orcs, all with different cultures, with different weapons, and different shields and patterns and tactics.

"Before we could loose the first arrow, we had to design the landscape itself and figure out, 'Okay, if we have 10,000 orcs, how much room are they going to take up?' " Jackson said. " 'Are they going to fill up the valley or look like a speck?' Then we could start drawing the arrows on the schematics."

Having directed the Lord of the Rings trilogy and two Hobbit films, Jackson, 52, said he follows one cardinal rule when filming battle scenes. "We're not allowed to go more than two or three shots of anonymous people fighting without cutting back to our principal characters. Otherwise the audience just ends up with battle fatigue."

All the stars including Elijah Wood, Orlando Bloom, Martin Freeman and Sir Ian McKellen will return for the much anticipated finale. The Hobbit: A Battle of Five Armies is scheduled for a Christmas worldwide release.

All of The Lord of The Rings and Hobbit films have grossed over or just under one billion dollars, said Daily Mail.