Dogtown and Z-Boys

Dogtown and Z-Boys, director Stacy Peralta’s examination of a ragtag group of ’70s California skateboarders, rarely aims to be anything more than an unquestioning celebration of its sun-soaked subjects. But if a documentary is going to be all surface, it doesn’t hurt that ”Dogtown” — a pastiche of zippily edited stunts and stories, set to stoner-rock titans like Zeppelin and T. Rex — has a surface as sleek and inviting as a freshly sanded half-pipe.