The Chronicles of Riddick may not be the most scintillating title for a sci-fi blockbuster devoted to the joys of interplanetary butt kicking, but I suppose its faux-Asimov pomposity does at least beat ''The Chronicles of the Guy Vin Diesel Played in Pitch Black.'' It's been four years since Diesel staked his claim to action stardom in that heightened B-movie ''Alien'' knockoff, and it's easy to chart his growth on screen: By now, there isn't a line of dialogue, no matter how trivial, that this thick-featured Gollum on 'roids wouldn't dare to overdo in his ''threatening'' mush-mouthed monotone.
When a man becomes a swaggering action star, it is generally because, like Schwarzenegger or Seagal, he is more or less incompetent at any other role. Diesel, however, made an honorable grunt in ''Saving Private Ryan,'' and he had a fast-break bluster in ''Boiler Room.'' He's a paradox: a tough-guy actor with a spark of true talent who is borderline incompetent at lunkish action roles. In ''The Chronicles of Riddick,'' Diesel once again tries to out-basso Isaac Hayes, and he treats a cheesy line like ''I bow to no man!'' not by understating it -- the way that, say, Stallone might -- but by pumping it up. He's the king of trying too hard; he turns self-adoring musclehead attitude into macho camp.
The modest virtues of ''Pitch Black,'' in which Diesel played the allegedly fearsome escaped convict Riddick by domesticating him enough to make him seem almost sweet, are mostly obliterated by Riddick, in which the returning writer-director, David Twohy, indulges in almost two hours of lovingly photographed hardware and mortal combat set amid the cities, skies, and deserts of one of those futuristic digital cosmospheres. This time Riddick, the sociopathic loner who knuckles under to no one, becomes a galactic gladiator facing down a brainwashing fascist with the redundant name of Lord Marshal (Colm Feore), who makes his pronouncements from within a tall burnished-silver palace that looks like it was decorated by the team of H.R. Giger and Thom Filicia.
There's one exciting moment in which Riddick and Kyra (Alexa Davalos), all grown up out of her androgynous ''Pitch Black'' disguise, swing across a mountain face inches from a nuclear blast. But ''The Chronicles of Riddick'' is mostly a ponderous chronicle. Judi Dench, as Marshal's soothsayer, shows up for just long enough to make you wonder what Judi Dench is doing in this movie, and Lord Marshal himself, with his high-minded talk of glory and sacrifice, sounds like he's recruiting for al-Qaeda. Any allegory, however, is abruptly buried by Twohy's fetishizing of armor and weapons. He lingers over the elegant serrated daggers and boxy machine guns, as well as an ax as elaborate as a designer palm leaf; even the jutting formations on the planet where Riddick and a band of rebel mercenaries get stranded look like razor-y knives. This is a movie so devoted to metal that it couldn't care less about the flesh it destroys.