Charging headlong into the fashion world with zippers, scrawled epithets, and rips and tears, the iconoclastic designer Vivienne Westwood forever changed youth culture. Now, with her Climate Revolution initiatives, she seeks to untangle “two snakes”: the capitalist, corporatized economy and its threat to our global ecology. Director Lorna Tucker’s appropriately idiosyncratic portrait follows one of our great impresarios — still soulful and ornery after all these years — as she manages a sprawling empire. Also in the frame is her partner, the singular Andreas Kronthaler (the inspiration for Sacha Baron Cohen’s outlandish “Bruno” character). Tucker reveals the behind-the-scenes tumult at Westwood’s nonstop atelier and accompanies her on a Greenpeace expedition to Antarctica. Along the way, the designer questions the purpose of a marketing department, scrubs plans to expand into China, and plays cat-and-mouse games with Tucker, who, gamely sidestepping her subject’s resistance, crafts an inspirational portrait. (PS)