A guilty displeasure, Santosh Sivan’s “Before the Rains,” produced by the gentility firm of Merchant-Ivory, is a genuine fallback from his punchy, pungent third feature, 1999’s “The Terrorist,” which was “presented” in the U.S. by John Malkovich. 1937 Kerala is the setting for a multiethnic affair, shot with consummate craft by Sivan, who works as his own cameraman. The genuine beauty of the filmmaking is undercut by an almost total absence of dramatic tension and sexual chemistry. With Linus Roache, Rahul Bose, Nandita Das, Jennifer Ehle, John Standing, Leopold Benedict, Indrajith Sukumaran, Lal Paul. (Ray Pride)