Just a year ago, soundstages [in Vancouver] were half empty. Production in a city whose vibrant movie business earned the nickname “Hollywood North” had plunged to its lowest level in six years. A sagging U.S. dollar had erased many of the cost advantages enticing studios. Seizing the opening, other countries and states used incentives to poach work. So British Columbia and other Canadian provinces answered with a fresh round of sweeteners layered on top of an already generous package. Now, studio lots are jammed until well into next year. Richard Verrier reports.