Centering the camera on the character - ios

Question

I am a beginner and I have started my first project. It should be a little game where you can run to the left and to the right. But I don't know how to set the camera settings.
I'd be very thankful if you could help me, tell me how I can improve my code and what is wrong.
Here is my Code:
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var ground:SKSpriteNode = SKSpriteNode()
var hero: MPCharacter!
var tree:MPTree!
override func didMoveToView(view: SKView) {
backgroundColor = UIColor(red: 155.0/255.0, green: 201.0/255.0, blue: 244.0/255.0, alpha: 1.0)
self.anchorPoint = CGPointMake(0.5, 0.5)
// --> hero <--
hero = MPCharacter()
hero.position = CGPointMake(frame.size.width/2, view.frame.size.height/2)
hero.zPosition = 100
hero.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(hero.size.width, hero.size.height))
hero.physicsBody!.dynamic = true
addChild(hero)
// --> ground <--
ground = SKSpriteNode(imageNamed: "ground")
ground.size = CGSizeMake(frame.size.width, frame.size.height/3)
ground.position = CGPointMake(frame.size.width/2, frame.size.height/2 - ground.size.height)
ground.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(frame.size.width, ground.size.height - 25))
ground.physicsBody!.dynamic = false
addChild(ground)
// --> Tree <--
tree = MPTree()
tree.position = CGPointMake(frame.size.width/2, ground.size.height + tree.size.height/3 - 10)
tree.zPosition = 10
tree.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(tree.size.width, tree.size.height - 10))
tree.physicsBody!.dynamic = false
addChild(tree)
// --> Physics <--
self.physicsWorld.gravity = CGVectorMake(0, -5.0)
self.physicsWorld.contactDelegate = self
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
for touch:AnyObject in touches {
let location = touch.locationInNode(self)
if location.x < CGRectGetMidX(self.frame) {
hero.physicsBody!.velocity = CGVectorMake(0, 0)
hero.physicsBody!.applyImpulse(CGVectorMake(-5, 10))
}
else {
hero.physicsBody!.velocity = CGVectorMake(0, 0)
hero.physicsBody!.applyImpulse(CGVectorMake(5, 10))
}
}
}
}

Answer 1

Im not quite sure what you are trying to achieve. One way to make your character 'run' to the left (or right) is by moving a background (and other game objects) to the left when the character is running right (and vice versa). This way your character will always be in the center of the screen, because he is not really moving, you create an 'illusion' that he is moving in your gameworld. Giving your character a run animation will make it look even better...
There is a tutorial on the website of Ray Wenderlich which also covers 'parallax scrolling':
http://www.raywenderlich.com/49625/sprite-kit-tutorial-space-shooter
Hope this helps..

Answer 2

If you're trying to center the camera on the player, Apple Docs provide you a nice example for how to do so over here (I would add code, but the best way to learn is to get your hands dirty). You might have to translate the methods to swift, but it is the general implementation for what you wish to do. The problem with the answer above is that if you would move the background, you would have to calculate the forces and the impulses directly and apply the inverse vectors to the background. This might require more processing than with simply moving the camera. Hope this helps!!