Cherished Hong Kong filmmakers Tsui Hark, Ringo Lam, and Johnnie To struggle to pool their creative resources in the 2007 heist-gone-awry thriller "Triangle," a feat which is, if nothing else, ambitious. Considering the quality of talent operating behind the camera, you'd expect this sort of movie to pop and sizzle on-screen, regardless of how complicated or contrived its script may be.