如何在Swift中拍攝移動的精靈？

Question

我想讓我的固定怪物在我的移動玩家身上射擊。玩家位置和怪物位置都獲得正確的值，並且該代碼被寫入每秒鐘被調用的函數中。現在彈丸出現，但不會離開怪物。除了.applyAngularImpulse之外，還有什麼我應該使用的嗎？

let deltaX = player.position.x - monster.position.x 
    let deltaY = player.position.y - monster.position.y 
    let angle = atan2(deltaY, deltaX) 

    monProjectile.physicsBody?.applyAngularImpulse(angle) 

Answer 1

UPDATE

說完看着你提供的代碼，我懷疑有兩兩件事是有過錯：

1）您指定一個「彈丸」的形象，我不能看在你的項目中。

2）你試圖施加角衝量（即自旋）而不是常規衝量（即方向加速度）。

要解決第一個問題，請爲您的射彈添加圖像。要解決第二個問題，請考慮使用applyImpulse()和CGVector。

原來的答覆

關閉我的頭頂，有可能會導致這樣幾件事情：

1）如何的衝動多少是你申請？打印出該值並查看您正在使用的編號。

2）你的彈丸在創建時是否與怪物重疊？如果是這樣，它可能會碰撞並卡住。

3）彈丸是否有可能完全與其他節點發生碰撞，例如：背景圖片？

對於您的SKView，您應該考慮將showsPhysics設置爲true，以便您可以更清楚地看到發生的情況。

Answer 2

func makeShoot() { 
    let Shoot:ShootClass = ShootClass.init() 
    Shoot.physicsBody = SKPhysicsBody(texture: Shoot.texture!, 
            size: Shoot.texture!.size()) 
    Shoot.position = (self.Shoot?.position)! 
    Shoot.currentPosition = (self.Shoot?.position)! 
    Shoot.physicsBody?.isDynamic = true 
    Shoot.physicsBody?.allowsRotation = false 
    Shoot.physicsBody?.affectedByGravity = false 
    Shoot.physicsBody?.friction = 0 
    Shoot.physicsBody?.restitution = 1 
    Shoot.physicsBody?.mass = 1 
    Shoot.physicsBody?.linearDamping = 0.0 
    Shoot.physicsBody?.angularDamping = 0.0 
    Shoot.physicsBody?.categoryBitMask = ShootCategory 
    Shoot.physicsBody?.collisionBitMask = BorderCategory 
    Shoot.physicsBody?.contactTestBitMask = BorderCategory 

    PlayingView.addChild(Shoot); 

    Shoot.physicsBody?.applyImpulse(CGVector(dx: 100, dy: 100)) 

    self.moveNodeToLocation(Shoot: Shoot) 
} 



override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { 
    let curTouch = touches.first! 
    let curPoint = curTouch.location(in: self) 
    if ((curPoint.x > 103.5 && curPoint.y > 50.0) || (curPoint.x < 840.0 && curPoint.y > 50.0)) { 
     StartingPoint = touches.first?.location(in: self) 
     direction?.isHidden = false 
     direction?.setScale(0.50) 
     FirstTouchLocater = SKSpriteNode(imageNamed: "ic_Shootz"); 
     FirstTouchLocater.position = curPoint 
     FirstTouchLocater.alpha = 0.5 
     self.addChild(FirstTouchLocater); 

    } 
    else{ 
     self.direction?.isHidden = true 
    } 
} 

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

    let point:CGPoint = (touches.first?.location(in: self))! 

    if point.y < 40 { 
     return 
    } 

    if !(isTouch!) { 
     isTouch = true 
    } 


    let dy:CGFloat = StartingPoint!.y - point.y 

    let size:CGFloat = dy*10/self.frame.height 

    if size < 2 && size > 0.50 { 
     direction?.setScale(size) 
    } 
    print("size ======> \(size)") 




    let curTouch = touches.first! 
    let curPoint = curTouch.location(in: self) 

    if (curPoint.x <= ((StartingPoint?.x)! + 20.0)) && ((curPoint.x + 20.0) >= (StartingPoint?.x)!) && (curPoint.y <= ((StartingPoint?.y)! + 20.0)) && ((curPoint.y + 20.0) >= (StartingPoint?.y)!){ 
     self.direction?.isHidden = true 
     FirstTouchLocater?.isHidden = true 
    } 
    else if ((curPoint.x > 103.5 && curPoint.y > 50.0) || (curPoint.x < 840.0 && curPoint.y > 50.0)) { 
     let deltaX = (self.direction?.position.x)! - curPoint.x 
     let deltaY = (self.direction?.position.y)! - curPoint.y 
     let angle = atan2(deltaY, deltaX) 

     let DegreesToRadians = CGFloat.pi/180 

     self.direction?.zRotation = angle + 90 * DegreesToRadians 
     self.direction?.isHidden = false 
     FirstTouchLocater?.isHidden = false 
    } 
    else{ 
     self.direction?.isHidden = true 
     FirstTouchLocater?.isHidden = true 
    } 
} 

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) { 
    if direction?.isHidden == false { 
     FirstTouchLocater.removeFromParent() 
     direction?.isHidden = true 
     direction?.setScale(0.1) 
     if timeThrow == nil && isTouch! 
     { 
      isTouch = false 
      counterY = 0; 

      let touch = touches.first 
      let touchLocation = touch?.location(in: self) 
      lastTouch = touchLocation 
      lastTouch1 = touchLocation 

      ShootThrow = 2 

      timeThrow = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(self.loadScreen), userInfo: nil, repeats: true) 
     } 
    } 
} 

func moveNodeToLocation(Shoot:SKSpriteNode) { 
    let dx = (lastTouch?.x)! - Shoot.position.x 
    let dy = (lastTouch?.y)! - Shoot.position.y 

    let speed1:CGFloat = 424 
    let hypo = hypot(dx, dy) 

    let newX = (speed1 * dx)/hypo 
    let newY = (speed1 * dy)/hypo 
    Shoot.physicsBody?.velocity = CGVector(dx:newX, dy: newY) 

} 

}