軸に沿ってスプライトを回転する

Question

SpriteKitでは、ユーザーが回転させるホイールのように、スプライトを軸（たとえば、スプライトの中心を通る軸）に沿って回転させる必要があります。

私はapplyTorque機能を使用しようとしましたが（角張っているだけで線形ではない力を加えるために）、私は画面上の異なる動きによって引き起こされる異なる力を扱うことができません適用する）。

この問題をどのように処理するかを教えてもらえますか？

Answer 1

あなたは右/左スワイプどのくらいの速に応じてボールを回転させるの答えです：

class GameScene: SKScene { 

    let speedLabel = SKLabelNode(text: "Speed: 0") 
    let wheel  = SKShapeNode(circleOfRadius: 25) 

    var recognizer: UIPanGestureRecognizer! 

    func pan(recognizer: UIPanGestureRecognizer) { 
    let velocity = recognizer.velocity(in: view!).x 

    // Play with this value until if feels right to you. 
    let adjustor = CGFloat(60) 

    let speed = velocity/adjustor 
    wheel.physicsBody!.angularVelocity = -speed 
    } 

    // Scene setup: 
    override func didMove(to view: SKView) { 
    removeAllChildren() 

    physicsBody = SKPhysicsBody(edgeLoopFrom: frame) 

    wheel.fillColor = .blue 
    wheel.physicsBody = SKPhysicsBody(circleOfRadius: 25) 
    wheel.physicsBody!.affectedByGravity = false 
    let wheelDot = SKSpriteNode(color: .gray, size: CGSize(width: 5, height:5)) 
    wheel.addChild(wheelDot) 
    wheelDot.position.y += 20 
    wheel.setScale(3) 

    speedLabel.setScale(3) 
    speedLabel.position.y = (frame.maxY - speedLabel.frame.size.height/2) - 45 

    recognizer = UIPanGestureRecognizer(target: self, action: #selector(pan)) 
    view.addGestureRecognizer(recognizer) 

    addChild(wheel) 
    addChild(speedLabel) 
    } 

    override func didSimulatePhysics() { 
    speedLabel.text = "Speed: \(abs(Int(wheel.physicsBody!.angularVelocity)))" 
    } 
} 

Answer 2

ここでは、画面の左右を押すかどうかによって時計回りまたは反時計回りにホイールを回転させる基本的な例を示します。速度を上げるためにホールド：ここ

class GameScene : SKScene { 

    enum Direction { case left, right } 

    var directionToMove: Direction? 

    let wheel = SKShapeNode(circleOfRadius: 25) 
    let speedLabel = SKLabelNode(text: "Speed: 0") 

    override func didMove(to view: SKView) { 
    // Scene setup: 
    anchorPoint = CGPoint(x: 0.5, y: 0.5) 
    removeAllChildren() 

    physicsBody = SKPhysicsBody(edgeLoopFrom: frame) 

    wheel.fillColor = .blue 
    wheel.physicsBody = SKPhysicsBody(circleOfRadius: 25) 
    wheel.physicsBody!.affectedByGravity = false 
    let wheelDot = SKSpriteNode(color: .gray, size: CGSize(width: 5, height:5)) 
    wheel.addChild(wheelDot) 
    wheelDot.position.y += 20 
    wheel.setScale(3) 


    speedLabel.setScale(3) 
    speedLabel.position.y = (frame.maxY - speedLabel.frame.size.height/2) - 45 

    addChild(wheel) 
    addChild(speedLabel) 
    } 

    // Change this to touchesBegan for iOS: 
    override func mouseDown(with event: NSEvent) { 
    // Change this to touches.first!.location(in: self) for iOS. 
    let location = event.location(in: self) 

    // Determine if touch left or right side: 
    if location.x > 0 { 
    directionToMove = .right 
    } 
    else if location.x < 0 { 
     directionToMove = .left 
    } 
    } 

    override func mouseUp(with event: NSEvent) { 
    // Stop applying gas: 
    directionToMove = nil 
    print("lol") 
    } 

    override func update(_ currentTime: TimeInterval) { 
    // This is how much speed we gain each frame: 
    let torque = CGFloat(0.01) 

    guard let direction = directionToMove else { return } 

    // Apply torque in the proper direction 
    switch direction { 
    case .left: 
     wheel.physicsBody!.applyTorque(torque) 
    case .right: 
     wheel.physicsBody!.applyTorque(-torque) 
    } 
    } 

    override func didSimulatePhysics() { 
    // Speedometer: 
    speedLabel.text = "Speed: \(abs(Int(wheel.physicsBody!.angularVelocity)))" 
    } 
}