We already reported that Vin Diesel has his eyes on two more Riddick sequels, but in the here-and-now, it’s all about “Babylon A.D.” his new sci-fi/action flick that opens Friday. In our exclusive interview with the star — viewable here — he reveals why he signed onto the project and how his film is an homage to the granddaddy of them all, Ridley Scott’s “Blade Runner.”