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

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.