My scene has a bunch of rectangles with physics bodies that are the same size as the rectangle. I like to anchor all of my objects to CGPointZero, however I\'ve noticed when
You need the anchorPoint only when you set your spriteNode's position. I don't quite understand why would you need to move physicsBody (which is the same size of node, I presume) to a corner... But you might find useful this class method [SKPhysicsBody bodyWithPolygonFromPath:path].
Here is a nice generator for that: http://dazchong.com/spritekit/