Pan Nalin has signed on to direct “Buddha,” the story of Siddhartha, for Barnet Bain Films. Shooting will start in the spring in India and Nepal. Bain and Nalin are producing; Peter Russell and Tinker Lindsay co-produce. Nalin’s first feature, “Samsara,” was shot in the Tibetan language and has grossed more than $20 million. His “Valley of the Flowers,” a $6 million production filmed in Hindi and Japanese, will be released theatrically in about 30 countries early next year.