Ben Affleck once built a Batcave entrance to a panic room in his house because of his love for the Caped Crusader. The movie star has come under fire after getting cast as Batman in the Man of Steel sequel, but his director pal Kevin Smith insists Affleck was destined to play Bruce Wayne's alter-ego. He reveals the actor's former home featured a bookcase that opened into a panic room. Smith says, "He brings me into the room and goes, 'Look at this'. There's an office room and this beautiful bookcase - he reached under and he clicked something and all of a sudden the bookcase opened. "I was like, 'No! You built a f**king Batcave?' And he was like, 'No I built a Batcave entrance!' When you went in behind the bookcase it was a panic room." And Smith is urging the comic book fanatics who have started taking aim at Affleck over his Batman casting to hold their judgment, insisting Affleck will be great as the Caped Crusader. He adds, "This dude has loved Batman going as far back as I can remember. He only did Daredevil because he loved Frank Miller's Dark Knight Returns. He's like, 'They're never going to make another Batman', because this was after Batman had nipples. So he was like, 'Daredevil's cool, and Miller wrote him as well'. So he liked the character, but it was always rooted in Batman. "He's always been into the notion. He'll honour the character. I honestly think the dude's a great actor, it makes absolute sense." But Batman fans aren't convinced Affleck's the right choice for the role - an online petition, launched to urge filmmakers to recast the part, has attracted over 70,000 signatures.