It’s an industry in which every inch of every moment matters. Working in a raw medium, the artists must maintain stamina to create their most convincing moods. And when an actor says, “I’m ready to shoot my scene right now!” it is best for the camera crew to oblige. The denizens of the adult film industry are the subject of Paul Thomas Anderson’s Boogie Nights (B-), a sometimes glorious, sometimes tedious glimpse at a cottage industry in L.A. in the ’70’s and ’80’s. The ensemble of Mark Wahlberg, Burt Reynolds, Heather Graham and Julianne Moore create a family even while casually shooting hardcore scenes and dealing with graphic situations. The film’s first half is as carefree as its second act is sometimes hard to watch. Ultimately it’s a triumph of acting and atmosphere, albeit short on plot.