The 3-D wasn’t working at the screening I attended, but, honestly, it would take several more dimensions to craft something special out of this adequate but unremarkable animated tale of a skinny Viking nerd-boy (voiced by Jay Baruchel) named Hiccup who befriends fire-breathing dragons, hoping to impress his father (Gerard Butler), a beefy Norseman with a Glasgow accent and triceps like tree trunks. Based on a children’s novel by Cressida Cowell and directed by Chris Sanders and Dean DeBlois, How to Train Your Dragon struggles to rise to the challenge of hitching a red-blooded fantasy action-adventure to a huggy-kissy message that covers all antiwar and eco bases. Father and son, though inevitably scheduled for reciprocal self-actualization (brain, say hello to brawn, and vice versa), spend much of the movie at loggerheads because junior would rather fly around on, instead of slay, his newfound scaly friend, whose cute, big poonim bears an incongruous resemblance to the critter from Lilo & Stitch. Intentionally or not, all of the dragons are built more for stand-up comedy than for terror, which means that aside from two fine battle scenes that bookend the movie, we have to make do in the drama department with the wan love that blossoms between Hiccup and a feisty young Vikingette voiced by America Ferrera. Better is some funny business when fledgling killers-in-training meet baby dragons-in-training, supervised by the deliciously hectoring voice of Craig Ferguson.