Question

我找到了关于如何让敌人向玩家移动的this答案。如果GameScene上有一个敌人，那就完美了。但是，如果我将另一个敌人添加到场景中，则只有一个移动而另一个静止。

以下是我到目前为止所有设置的代码。

var player: SKSpriteNode?

var spawnZombie = SKSpriteNode()

override func didMove(to view: SKView) {
    playerTexture = SKTexture(imageNamed: "player_2")
    player = SKSpriteNode(texture: playerTexture)
    player?.name = "player"
    player?.position = (pSpawnPoint?.position)!
    player?.setScale(0.5)
    self.addChild(player!)


    randomEnemy()
    randomEnemy()
}

这就是我的敌人的设置方式

func randomEnemy(){
    spawnPoint0 = childNode(withName: "spawnPoint_0") as? SKSpriteNode
    spawnPoint1 = childNode(withName: "spawnPoint_1") as? SKSpriteNode
    spawnPoint2 = childNode(withName: "spawnPoint_2") as? SKSpriteNode
    // Set up enemies
    enemy = SKSpriteNode(imageNamed: "enemy_2")
    enemy.name = "enemy"
    enemy.setScale(0.5)
    enemy.zPosition = 10
    enemy.physicsBody = SKPhysicsBody(rectangleOf: enemy.size)
    enemy.physicsBody?.categoryBitMask = PhysicsCatagory.Enemy
    enemy.physicsBody?.collisionBitMask = PhysicsCatagory.None
    enemy.physicsBody?.contactTestBitMask = PhysicsCatagory.Player
    enemy.physicsBody?.isDynamic = true
    enemy.physicsBody?.affectedByGravity = false

    let choice = Int(arc4random_uniform(3))
    switch choice {
    case 0:
        enemy.position = (spawnPoint0?.position)!
        self.addChild(enemy)
        break

    case 1:
        enemy.position = (spawnPoint1?.position)!
        self.addChild(enemy)
        break

    case 2:
        enemy.position = (spawnPoint2?.position)!
        self.addChild(enemy)
        break
    default:
        print("something went wrong")
    }
}

override func update(_ currentTime: TimeInterval) {

   let location = player?.position

    //Aim
    let dx = (location?.x)! - enemy.position.x
    let dy = (location?.y)! - enemy.position.y
    let angle = atan2(dy, dx)

    enemy.zRotation = angle - 3 * .pi/2

    //Seek
    let velocityX =  cos(angle) * enemySpeed
    let velocityY =  sin(angle) * enemySpeed

    enemy.position.x += velocityX
    enemy.position.y += velocityY
}

任何想法为什么每当我运行两次这个功能时，只有一个敌人会移动？提前致谢。

Answer 1

你将两个敌人放在同一个敌人变量中。所以当你试图移动敌人时，你基本上是移动分配给该变量的最后一个。

你需要做的就是把它们放在一个数组中，然后从阵列中移出所有的敌人。

let enemies = [SKSpriteNode]()


func randomEnemy() {

    //...other code blah blah blah
    enemies.append(enemy)
}

并在更新功能

中

override func update(_ currentTime: TimeInterval) {

   let location = player?.position

    for enemy in enemies {
        //Aim
        let dx = (location?.x)! - enemy.position.x
        let dy = (location?.y)! - enemy.position.y
        let angle = atan2(dy, dx)

        enemy.zRotation = angle - 3 * .pi/2

        //Seek
        let velocityX = cos(angle) * enemySpeed
        let velocityY = sin(angle) * enemySpeed

        enemy.position.x += velocityX
        enemy.position.y += velocity
    }
}

现在你可能想要查看子类的敌人并在该类中具有移动功能，但这超出了你的问题的范围。这应该让你开始。

SpriteKit：更新几个敌人位置以跟随玩家

1 个答案: