Question

我创建了一个带有physicsBody edgeFromLoop圆形的SKNode，其中添加了8个小圆形节点。和8个圆形节点正在使用父级圆形节点内的CMMotionManager移动。用快速动作摇动一些球从屏幕上消失。下面给出了SKScene类

只有当有人随机摇动手机时，球才会消失。

最初有8个球，但经过一定程度的摇晃后减少了。

class GameScene: SKScene {
  let motionManager = CMMotionManager()

  var Circle = SKShapeNode(circleOfRadius: 108)
  var sound = SKAction.playSoundFileNamed(getRandomSound(), waitForCompletion: false)
  var collisionBitmasks: [UInt32] = [UInt32]()

  override func didMove(to view: SKView) {

    Circle.fillTexture = SKTexture.init(image: UIImage.init(named: "img_Ball") ?? UIImage())
    Circle.position = CGPoint.init(x: 0, y: 0)
    Circle.name = "defaultCircle"
    Circle.lineWidth = 0.0
    Circle.fillColor = SKColor.lightGray.withAlphaComponent(0.8)
    Circle.physicsBody = SKPhysicsBody.init(edgeLoopFrom: UIBezierPath.init(ovalIn: CGRect.init(x: Circle.frame.minX + 12,
                                                                                                y: Circle.frame.minY + 12,
                                                                                                width: Circle.frame.width - 24,
                                                                                                height: Circle.frame.height - 24)).cgPath)
    Circle.physicsBody?.isDynamic = true
    Circle.physicsBody?.affectedByGravity = false
    Circle.physicsBody?.allowsRotation = false
    addChild(Circle)
    self.physicsWorld.contactDelegate = self
    startAcceleroMeter()
    for index in 1...8 {
      addBalls(index)
    }
  }

  func stop() {
    motionManager.stopAccelerometerUpdates()
    Circle.children.forEach { (ball) in
      ball.physicsBody?.isDynamic = false
      ball.physicsBody?.affectedByGravity = false
    }
  }

  func startAcceleroMeter() {
    Circle.children.forEach { (ball) in
      ball.physicsBody?.isDynamic = true
      ball.physicsBody?.affectedByGravity = true
    }
    motionManager.startAccelerometerUpdates()
    motionManager.accelerometerUpdateInterval = 0.1
    motionManager.startAccelerometerUpdates(to: .main) { (motionData, error) in
      let gravity = CGVector.init(dx: (motionData?.acceleration.x ?? 0.0) * 20, dy: (motionData?.acceleration.y ?? 0.0) * 20)
      print(gravity)
      self.physicsWorld.gravity = gravity

    }
  }

  func stopPlaying() -> [String] {
    var dictionary = [String]()

    for (_, ball) in (Circle.children).enumerated() {
      dictionary.append("\(ball.position.x), \(ball.position.y), 0.0")
    }
    return dictionary
  }

  func addBalls(_ ballNo: Int) {
    let ball = SKShapeNode.init(circleOfRadius: 12)
    ball.name = "ball\(ballNo)"
    ball.fillTexture = SKTexture.init(linearGradientWithAngle: CGFloat.pi, colors: [BallColors(rawValue: ballNo)?.toUIColor(false) ?? UIColor(), BallColors(rawValue: ballNo)?.toUIColor(true) ?? UIColor()], locations: [0, 1], size: ball.frame.size)
    ball.fillColor = UIColor.white
    ball.physicsBody = SKPhysicsBody.init(circleOfRadius: 12)
    ball.physicsBody?.isDynamic = true
    ball.physicsBody?.affectedByGravity = true
    ball.physicsBody?.allowsRotation = true
    ball.physicsBody?.friction = 0.2
    ball.physicsBody?.restitution = 0.9
    ball.physicsBody?.linearDamping = 0.1
    ball.physicsBody?.angularDamping = 0.1
    ball.physicsBody?.mass = 0.349065870046616
    ball.physicsBody?.usesPreciseCollisionDetection = true
    ball.position = CGPoint(x: Circle.frame.midX - CGFloat(ballNo), y: Circle.frame.midY - CGFloat(ballNo))
    ball.physicsBody?.fieldBitMask = 1
    ball.physicsBody?.categoryBitMask = UInt32.init(ballNo + 100)
    let collisionBitMask = UInt32.init(ballNo + 20) | UInt32.init(ballNo + 100)
    collisionBitmasks.append(collisionBitMask)
    ball.physicsBody?.collisionBitMask =  collisionBitMask //To be different for each
    ball.physicsBody?.contactTestBitMask = UInt32.init(ballNo + 20)
    Circle.addChild(ball)
  }

  override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

  }

  override func update(_ currentTime: TimeInterval) {
    // Called before each frame is rendered
  }

}

extension GameScene: SKPhysicsContactDelegate {
  func didBegin(_ contact: SKPhysicsContact) {
    if collisionBitmasks.contains(contact.bodyA.collisionBitMask) && collisionBitmasks.contains(contact.bodyB.collisionBitMask) {
      run(sound)
    }
  }
}

Answer 1

这里需要隐藏的魔法。每个小球都增加了一个约束，可以防止高速发生任何事故：

   ball.constraints = [SKConstraint.distance(SKRange(upperLimit: 108 - 12), to: Circle)]

SKNode内部的子节点通过应用CMMotionManager的快速摇动设备移动球而消失

1 个答案: