Off-screen footage of the Warcraft movie by Legendary Pictures has leaked from San Diego Comic-Con.

It shows the orc Durotan, father of Thrall, marching with his Frostwolf clan towards the Dark Portal on Draenor. There, spurred on by spooky warlock Gul'dan, the old Horde pours through door to Azeroth. According to The Verge there was more footage shown after this point, of the orcs meeting resistance on the other side.

The footage, albeit poor quality, gives us a guiding impression of what the rest of the film, directed by Duncan Jones (Moon, Source Code), will look like. Industrial Light & Magic, the studio responsible for Mark Ruffalo's Hulk, is bringing the fantasy characters to life.

Actors playing orcs include Toby Kebbell - the crazy crack-smoking guy in Guy Ritchie's RocknRolla (2008) - as Durotan, Robert Kazinsky (Pacific Rim, True Blood) as Ogrim, and Clancy Brown (Captain Hadley in Shawshank Redemption) as Blackhand.

Director Duncan Jones told io9 at Comic-Con that Warcraft was "pretty much a finished movie", even though it has a 10th June 2016 release date. He also hinted strongly at a possible trilogy of Warcraft films.

"I know that it's good," he said. "I've shown it to people I trust and whose opinions I respect, and who are honest with me, and they've said it's good. So now I just clench my fists and grit my teeth and wait for everyone else to see it.

"Legendary are very smart, they want to see how things play out. We have a movie we're very proud of. I don't think anyone is going to be disappointed after this. And if it goes well, I am pretty convinced that Chris Metzen [Blizzard's story guru] and I have a very good idea of what story we can tell in three films given the opportunity."

Earlier this week a nifty interactive trailer was released for the Warcraft movie. It shows a griffin's flight over the city of Stormwind and, being interactive, allows you to look around as you fly.