swift - 侧滚动 Swift SpriteKit 游戏中的 SKPhysicsJointPin

Question

我正在尝试在 SpriteKit 中开发横向滚动游戏。我的问题如下：

• 我正在尝试在我的游戏中添加一根绳子，但是当我开始游戏时它会断掉。当我将这条绳索添加到非滚动游戏中时，它运行得非常好。我认为问题出在场景锚点之类的地方，但我就是想不通。我已经有一个星期的“辛苦”了。我有一个名为“世界”的 SKNode，所有对象都附加到它上面，我将“世界”向左移动，我将“相机”放在我的玩家身上，所以玩家向右移动，所有其他对象都是被留下来。

这是我的代码：

• 这是“世界”的功能

  override func didSimulatePhysics() {
     centerOnNode(ball)    
  }
  
  func centerOnNode(node: SKNode) {
     positionInScene = convertPoint(node.position, fromNode: node.parent!)
     world.position = CGPointMake(world.position.x - positionInScene.x + 100, world.position.y)
  }
  

• 这是绳子的功能

  let length = 5
  let startPosition = CGPointMake(CGRectGetMaxX(self.frame), CGRectGetMaxY(self.frame))
  var chains : [SKNode] = []
  
  func addChain() {
  
      let chainHolder = SKSpriteNode(imageNamed: "chainHolder")
      chainHolder.position = startPosition
  
      chains.append(chainHolder)
      world.addChild(chainHolder)
  
      chainHolder.physicsBody = SKPhysicsBody(circleOfRadius: chainHolder.size.width / 2)
      chainHolder.physicsBody?.dynamic = false
  
      for i in 0..<length {
  
          let chainRing = SKSpriteNode(imageNamed: "chainRing")
          let offset = chainRing.size.height * CGFloat(i + 1)
          chainRing.position = CGPointMake(startPosition.x, startPosition.y - offset)
          chainRing.name = String(i)
  
          chains.append(chainRing)
          world.addChild(chainRing)
  
          chainRing.physicsBody = SKPhysicsBody(rectangleOfSize: chainRing.size)
      }
  
      for i in 1...length {
  
          let nodeA = chains[i - 1]
          let nodeB = chains[i]
          let joint = SKPhysicsJointPin.jointWithBodyA(nodeA.physicsBody, bodyB: nodeB.physicsBody,
              anchor: CGPointMake(CGRectGetMidX(nodeA.frame), CGRectGetMinY(nodeA.frame)))
  
          /*var pt = CGPointMake(world.position.x, world.position.y);
          pt = convertPoint(pt, fromNode: world);
  
          pt.x += scene.size.width * scene.anchorPoint.x;
          pt.y += scene.size.height * scene.anchorPoint.y;
          //pt.x += nodeA.position.x //- nodeA.frame.size.width / 2
          //pt.y += nodeA.position.y
  
          let joint = SKPhysicsJointPin.jointWithBodyA(nodeA.physicsBody, bodyB: nodeB.physicsBody,
              anchor: pt)*/
  
          self.physicsWorld.addJoint(joint)
      }
  }
  

我应该如何制作这条绳索，使其不再断裂？任何帮助，将不胜感激。谢谢！