Change SpriteNode PhysicsBody Size at Run Time

Question

I want to be able to change a node's physicsBody height when the user swipes downwards, but have not been able to find out how to do this, beside resetting the entire physicsBody.

When I originally load the node, I use the below code:

    nodeHero.color = UIColor .grayColor()
    nodeHero.size.width = 20
    nodeHero.size.height = 45
    nodeHero.position.x = -frame.size.width/2 + 45
    nodeHero.position.y = pointMainY + 30 + nodeHero.size.height/2
    nodeHero.zPosition = 110

    nodeHero.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(nodeHero.size.width, nodeHero.size.height))
    nodeHero.physicsBody?.mass = 1
    nodeHero.physicsBody?.angularVelocity = 0
    nodeHero.physicsBody?.allowsRotation = false
    nodeHero.physicsBody?.restitution = 0
    nodeHero.physicsBody?.categoryBitMask = bitHero

    addChild(nodeHero)

And when I swipe down, I want to be able to do something like this (this doesn't work):

    nodeHero.size.height = 28
    nodeHero.physicsBody?.size.height = 28

But instead I have to use the nodeHero.physicsBody = SKPhysicsBody() again, which resets all the other physicsBody properties, so I have to do this:

    nodeHero.size.height = 28

    nodeHero.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(nodeHero.size.width, nodeHero.size.height))
    nodeHero.physicsBody?.mass = 1
    nodeHero.physicsBody?.angularVelocity = 0
    nodeHero.physicsBody?.allowsRotation = false
    nodeHero.physicsBody?.restitution = 0
    nodeHero.physicsBody?.categoryBitMask = bitHero

Unpin

If you run a scale action on a node it seems that its physics body will also change: #24638586 – Ferrocene

Answer 1

According to SpriteKit documentation the area of a SKPhysicsBody can't be modified, so you need to create another SKPhysicsBody instance and copy the values you want to keep from the previous instance.

Pronuba

Ricardo Amores is right you can't resize physicsBody at run time you need to recreate it and assign back to your texture – Excrement