Last week, we reported that the villainous Ultron played by James Spader in Marvel's Avengers: Age of Ultron will be much different than his portrayal in the comic books. Director Joss Whedon revealed that Ultron is a robot who is "completely irrational." During a new interview, the filmmaker added even more details, stating that, unlike in the comics, Ultron's face is fully articulated. Here's what the director had to say, adding that James Spader's voice can go from utter evil to comedic in the blink of an eye.

"He has the voice, this terrifying, 'I own everything' evil voice, and then suddenly he'll just get very peevish about something. He can go from very intense to very comedic and get there on a dime and beautifully. In the comics, his face can only do one thing, but in the movie, his face is very articulated."

The filmmaker also revealed that the motion capture process was quite a trying one for James Spader, since he wasn't able to wear his glasses on the set.

"It was a nightmare for James, because he wears glasses, which he could not wear, and he's wearing a helmet with two cameras with lights on them, shining into his eyes, and he has to go around set like he's an eight-foot robot, moving quickly and confidently over all these sets, and he's basically like, 'Don't fall! I can't see anything.' He literally got there, and the next morning he was in that suit, doing that scene, and afterwards, he was like, 'Thank you for the weirdest day of my life. It was tremendous fun.' He went for it."