Though there are occasional forays into location shooting, Roma is mainly a tour de force of studio evocation; the warm, embracing chaos of a young man’s arrival in Rome in the late 1930s; the infernal quality of arrival today, stuck in traffic, braziers flickering against hard, driving rain; a 1940s brothel, more intimidating than seductive; a fashion show for clerics; and, hauntingly, archaeologists discovering exquisite frescoes that fade even as they watch.