xcode - 如何停止对 SKSpriteNode 施加力？

Question

我有几个彼此相邻排列的小桨，尺寸约为 50x10，不断地从左到右、从右到左移动，它们也会时不时地随机停止移动并变得静止。有一个球朝他们落下，当击中桨时，如果桨没有移动并且静止，球会从桨上弹开并直接向上飞去。然而，如果 Racket 正在移动并且球在此期间击中其中一个 Racket ，则球不会击中 Racket 并向右返回，而是击中 Racket 并开始向右或向左移动(取决于 Racket 的方向)移动)同时返回。我试图让球立即返回，即使它在移动时撞到 Racket (几乎是一个永远在 Racket 上弹跳的球)。

我尝试了几种不同的方法来解决这个问题，但我认为我错过了一些重要的事情，使其表现得像这样。这是代码:

class GameScene: SKScene, SKPhysicsContactDelegate {
        let greenPaddle = SKSpriteNode(imageNamed: "Green")
        var ball = SKSpriteNode()

        let ballCategory: UInt32 = 1 << 0
        let greenPaddleCategory: UInt32 = 1 << 1

        override func didMoveToView(view: SKView) {

            self.physicsWorld.contactDelegate = self

            greenPaddle.position = CGPoint(x: 0, y: frame.size.height / -6.5)
            greenPaddle.physicsBody = SKPhysicsBody(rectangleOfSize: greenPaddle.size)
            greenPaddle.physicsBody!.affectedByGravity = false
            greenPaddle.physicsBody!.dynamic = false

            greenPaddle.physicsBody!.categoryBitMask = greenPaddleCategory
            greenPaddle.physicsBody!.contactTestBitMask = ballCategory


          ball = SKSpriteNode(imageNamed: "Red")
          ball.position = CGPoint(x: self.frame.size.width / 2, y: self.frame.size.height / 2)
          ball.physicsBody = SKPhysicsBody(circleOfRadius: ball.size.height / 2)
          ball.physicsBody!.friction = 0
          ball.physicsBody!.restitution = 1
          ball.physicsBody!.linearDamping = 0
          ball.physicsBody!.allowsRotation = false

         ball.physicsBody!.categoryBitMask = ballCategory
         ball.physicsBody!.contactTestBitMask = greenPaddleCategory

         addChild(circle)
    }

    func didBeginContact(contact: SKPhysicsContact) {

        let bodyA = (contact.bodyA.categoryBitMask <= contact.bodyB.categoryBitMask) ? contact.bodyA : contact.bodyB
        let bodyB = (contact.bodyA.categoryBitMask <= contact.bodyB.categoryBitMask) ? contact.bodyB : contact.bodyA

        if (bodyA.categoryBitMask) == ballCategory && (bodyB.categoryBitMask) == greenPaddleCategory {

            greenPaddle.physicsBody!.friction = 0
            greenPaddle.physicsBody!.restitution = 0  
    }

}

Answer 1

我不太明白这个问题；但是，您忘记在 didmovetoview 中设置物理世界。

 self.physicsWorld.contactDelegate = self

如果问题是联系人不起作用，这会起作用:)