swift - SpriteKit 粒子文件位置

Question

我的 SpriteKit 游戏中爆炸粒子的定位有问题。当导弹与敌人相撞时，我称之为“func 爆炸”，但爆炸不是在被杀死的敌人所在的地方，而是在屏幕中间。我已将“explosion.position”设置为与“enemy.position”相匹配，但爆炸仍然发生在屏幕中间。我该如何更改它以使爆炸位置与被杀死的敌人的位置相同？

func spawnExplosion() {
    let explosionEmmiter = Bundle.main.path(forResource: 
    "ParticleExplosion", ofType: "sks")
    let explosion = NSKeyedUnarchiver.unarchiveObject(withFile: 
    explosionEmmiter as! String) as! SKEmitterNode

    explosion.position = CGPoint(x: enemy.position.x, y: 
    enemy.position.y)

    explosion.zPosition = 3
    explosion.targetNode = self

    self.addChild(explosion)

    let wait = SKAction.wait(forDuration: 0.5)
    let removeExplosion = SKAction.run {
        explosion.removeFromParent()
    }

    self.run(SKAction.sequence([wait, removeExplosion]))
}


func didBegin(_ contact: SKPhysicsContact) {

    var firstBody = SKPhysicsBody()
    var secondBody = SKPhysicsBody()

    if contact.bodyA.node?.name == "Enemy" {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if firstBody.node?.name == "Enemy" && secondBody.node?.name == 
    "Missile" {
        spawnExplosion()
    } 

func createEnemiesLeft() {

    let enemyTexture1 = SKTexture(imageNamed: "Enemy1")
    let enemyTexture2 = SKTexture(imageNamed: "Enemy2")
    let enemyTexture3 = SKTexture(imageNamed: "Enemy3")
    let enemyTexture4 = SKTexture(imageNamed: "Enemy4")
    let enemyTexture5 = SKTexture(imageNamed: "Enemy5")
    let enemyTexture6 = SKTexture(imageNamed: "Enemy6")
    let enemyTexture7 = SKTexture(imageNamed: "Enemy7")
    let enemyTexture8 = SKTexture(imageNamed: "Enemy8")
    let enemyTexture9 = SKTexture(imageNamed: "Enemy9")
    let enemyTexture10 = SKTexture(imageNamed: "Enemy10")

    let animation = SKAction.animate(with: [enemyTexture1, 
     enemyTexture2, enemyTexture3, enemyTexture4, enemyTexture5, 
     enemyTexture6, enemyTexture7, enemyTexture8, enemyTexture9, 
     enemyTexture10], timePerFrame: 0.1)

    let makeEnemyRun = SKAction.repeatForever(animation)

    let enemy = SKSpriteNode(texture: enemyTexture1)
    enemy.name = "Enemy"
    enemy.setScale(0.1)
    enemy.anchorPoint = CGPoint(x: 0.5, y: 0.5)
    enemy.physicsBody = SKPhysicsBody(circleOfRadius: enemy.size.height 
    / 2)
    enemy.physicsBody?.categoryBitMask = ColliderType.Enemy
    enemy.physicsBody?.affectedByGravity = false
    enemy.zPosition = 3

    enemy.position.y = self.frame.height + 100
    enemy.position.x = CGFloat.randomBetweenNumbers(firstNum: -347.5, 
    secondNum: -85)

    enemy.run(makeEnemyRun)


    self.addChild(enemy)

    let destination = self.frame.height * 0.5
    let move = SKAction.moveTo(y: -destination, duration: 
    TimeInterval(10))
    let remove = SKAction.removeFromParent()

    enemy.run(SKAction.sequence([move, remove]), withKey: 
    "MoveEnemiesLeft")

}

func spawnEnemiesLeft() {

    let spawn = SKAction.run({ () -> Void in
        self.createEnemiesLeft()
    })

    let delay = SKAction.wait(forDuration: TimeInterval(1))
    let sequence = SKAction.sequence([spawn, delay])

    self.run(SKAction.repeatForever(sequence), withKey: 
    "SpawnEnemiesLeft")
}

func createEnemiesRight() {

    let enemyTexture1 = SKTexture(imageNamed: "Enemy1")
    let enemyTexture2 = SKTexture(imageNamed: "Enemy2")
    let enemyTexture3 = SKTexture(imageNamed: "Enemy3")
    let enemyTexture4 = SKTexture(imageNamed: "Enemy4")
    let enemyTexture5 = SKTexture(imageNamed: "Enemy5")
    let enemyTexture6 = SKTexture(imageNamed: "Enemy6")
    let enemyTexture7 = SKTexture(imageNamed: "Enemy7")
    let enemyTexture8 = SKTexture(imageNamed: "Enemy8")
    let enemyTexture9 = SKTexture(imageNamed: "Enemy9")
    let enemyTexture10 = SKTexture(imageNamed: "Enemy10")

    let animation = SKAction.animate(with: [enemyTexture1, 
    enemyTexture2, enemyTexture3, enemyTexture4, enemyTexture5, 
    enemyTexture6, enemyTexture7, enemyTexture8, enemyTexture9, 
    enemyTexture10], timePerFrame: 0.1)

    let makeEnemyRun = SKAction.repeatForever(animation)

    let enemy = SKSpriteNode(texture: enemyTexture1)
    enemy.name = "Enemy"
    enemy.setScale(0.1)
    enemy.anchorPoint = CGPoint(x: 0.5, y: 0.5)
    enemy.physicsBody = SKPhysicsBody(circleOfRadius: enemy.size.height 
    / 2)
    enemy.physicsBody?.categoryBitMask = ColliderType.Enemy
    enemy.physicsBody?.affectedByGravity = false
    enemy.zPosition = 3

    enemy.position.y = self.frame.height + 100
    enemy.position.x = CGFloat.randomBetweenNumbers(firstNum: 85, 
    secondNum: 347.5)

    enemy.run(makeEnemyRun)

    self.addChild(enemy)

    let destination = self.frame.height * 0.5
    let move = SKAction.moveTo(y: -destination, duration: 
    TimeInterval(10))
    let remove = SKAction.removeFromParent()

    enemy.run(SKAction.sequence([move, remove]), withKey: 
    "MoveEnemiesRight")

}

func spawnEnemiesRight() {

    let spawn = SKAction.run({ () -> Void in
        self.createEnemiesRight()
    })

    let delay = SKAction.wait(forDuration: TimeInterval(1))
    let sequence = SKAction.sequence([spawn, delay])

    self.run(SKAction.repeatForever(sequence), withKey: 
    "SpawnEnemiesRight")
}


}

Answer 1

好的，你正在创造很多敌人，你必须获得碰撞位置。所以:

func spawnExplosion(pos:CGPoint) {
    let explosionEmmiter = Bundle.main.path(forResource: 
    "ParticleExplosion", ofType: "sks")
    let explosion = NSKeyedUnarchiver.unarchiveObject(withFile: 
    explosionEmmiter as! String) as! SKEmitterNode

    explosion.position = pos

    explosion.zPosition = 3
    explosion.targetNode = self

    self.addChild(explosion)

    let wait = SKAction.wait(forDuration: 0.5)
    let removeExplosion = SKAction.run {
        explosion.removeFromParent()
    }

    self.run(SKAction.sequence([wait, removeExplosion]))
}


func didBegin(_ contact: SKPhysicsContact) {


    var firstBody = SKPhysicsBody()
    var secondBody = SKPhysicsBody()

    if contact.bodyA.node?.name == "Enemy" {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if firstBody.node?.name == "Enemy" && secondBody.node?.name == 
    "Missile" {
        spawnExplosion(pos: firstBody.node.position)
    }