Entertaining but shallow, this 1992 Hollywood roast of the film industrydirected by Robert Altman, and adapted by Michael Tolkin from his own novelis supposed to be scathing, but the pleasure it affords is like what you get from watching the Oscars: celebrity spotting and in-jokes. The setup is a would-be noir situation: a studio executive (Tim Robbins) nervous about his position starts to get anonymous threatening mail from a disgruntled screenwriter and winds up committing a murder. As is customary in Altman ensemble pieces, the surface activity keeps one occupied, but never adds up to much because none of the characters is developed beyond the cartoon level; and the snobby sense of knowingness that’s over everything is uncomfortably close to what the movie is supposed to be dissecting. With Greta Scacchi, Fred Ward, Whoopi Goldberg, Peter Gallagher, Brion James, Cynthia Stevenson, Vincent D’Onofrio, and more than 60 cameos. R, 123 min. (JR)