Swift version: 5.1
Enabling physics in SpriteKit is just one line of code, but sometimes you want your physics to be a little more nuanced. For example, your player might have circle physics and should respond to gravity, whereas walls might have rectangle physics and not respond to gravity – they are there to be bounced off, but nothing more.
This problem is solved in SpriteKit by using the
isDynamic property. It's
true by default, which means that your objects respond to the world's environment as you would expect, but if you set it to be
false then you get an object that has active physics but doesn't move as a result of those physics.
Here's an example:
let wall = SKSpriteNode(imageNamed: "wall") wall.position = CGPoint(x: 512, y: 0) wall.physicsBody = SKPhysicsBody(circleOfRadius: wall.size.width / 2.0) wall.physicsBody?.isDynamic = false addChild(wall)
SAVE 20% ON iOS CONF SG The largest iOS conference in Southeast Asia is back in Singapore for the 5th time in January 2020, now with two days of workshops plus two days of talks on SwiftUI, Combine, GraphQL, and more! Save a massive 20% on your tickets by clicking on this link.
Available from iOS 7.0 – see Hacking with Swift tutorial 11
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.