NEW! Master Swift design patterns with my latest book! >>

How to add pixel-perfect physics to an SKSpriteNode

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

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Need to know Objective-C fast?

I wrote a book dedicated to teaching Objective-C to developers who already know Swift – it's the fastest way to get up to speed!

MASTER SWIFT NOW
Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Practical iOS 11 Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Click here to visit the Hacking with Swift store >>