How to add pixel-perfect physics to an SKSpriteNode

Written by Paul Hudson    @twostraws

Pixel-perfect physics is just one line of code in SpriteKit. Don't believe me? Here you go:

player = SKSpriteNode(imageNamed: "player")
player.position = CGPoint(x: 100, y: 384)
player.physicsBody = SKPhysicsBody(texture: player.texture!, size: player.size)

That last line is the one that does the magic: SpriteKit will use the alpha values of your sprite (i.e., the transparent pixels) to figure out which parts should be part of a collision.

As you might imagine, pixel-perfect collision detection is significantly slower than using rectangles or circles, so you should use it carefully.

Available from iOS 7.0 – see Hacking with Swift tutorial 23

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