3

我正在开发一个简单的游戏，它有一根弹性绳子固定在屏幕中间，还有一个球连接到绳子的另一端。通过在屏幕上移动手指，您可以移动球，这个想法是能够通过将球拉向底部来向上抛球。

到目前为止，我的代码如下所示：

var ball = SKSpriteNode(imageNamed: "Ball")

override func didMove(to view: SKView) {
    var ropeSegments = [SKSpriteNode]()

    let ropeHolder = SKSpriteNode(imageNamed: "RopeHolder")
    ropeHolder.position = CGPoint(x: frame.midX, y: frame.midY)
    ropeSegments.append(ropeHolder)
    addChild(ropeHolder)

    ropeHolder.physicsBody = SKPhysicsBody(circleOfRadius: ropeHolder.size.width / 2)
    ropeHolder.physicsBody?.isDynamic = false

    for i in 0..<30 {
        let ropeSegment = SKSpriteNode(imageNamed: "RopeTexture")
        let offset = ropeSegment.size.height * CGFloat(i + 1)
        ropeSegment.position = CGPoint(x: ropeHolder.position.x, y: ropeHolder.position.y - offset)
        ropeSegments.append(ropeSegment)
        addChild(ropeSegment)

        ropeSegment.physicsBody = SKPhysicsBody(rectangleOf: ropeSegment.size)
    }

    for i in 1..<31 {
        let nodeA = ropeSegments[i - 1]
        let nodeB = ropeSegments[i]
        let joint = SKPhysicsJointPin.joint(withBodyA: nodeA.physicsBody!, bodyB: nodeB.physicsBody!, anchor: CGPoint(x: nodeA.frame.midX, y: nodeA.frame.midY))

        physicsWorld.add(joint)
    }

    ball.position = CGPoint(x: frame.midX, y: ropeSegments.last!.position.y - ball.size.height / 2)
    ball.physicsBody = SKPhysicsBody(circleOfRadius: ball.size.width / 2)
    addChild(ball)

    let joint = SKPhysicsJointPin.joint(withBodyA: ropeSegments.last!.physicsBody!, bodyB: ball.physicsBody!, anchor: CGPoint(x: ropeSegments.last!.frame.midX, y: ropeSegments.last!.frame.midY))
    physicsWorld.add(joint)

    let moveAction = SKAction.move(to: CGPoint(x: frame.midX - 100, y: frame.midY), duration: 0.5)
    ball.run(moveAction)
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches {
        let point = touch.location(in: self)
        ball.position = point
    }
}

绳子的行为非常像现实生活中的绳子，但它根本没有弹性。我可以随心所欲地拉球，但是绳索节点以非常慢的方式回到默认状态，因此无法将球扔来扔去。

我尝试使用SKPhysicsJointSpring而不是，SKPhysicsJointPin但它的行为几乎相同。有什么建议么？

4

0 回答 0