Question

我遇到的问题是，初始化精灵时，我用相同的方式定义了另一个精灵，并且该精灵显示它具有物理体，因为我看到了绿色轮廓，但是下面的该精灵没有绿色轮廓它，我认为在创建SKPhysicsBody时出现问题，或者可能是因为我在随机位置创建了13个相同精灵的副本，如第二段代码所示。

    @objc func CreateNewAsteroid() {
     var asteroid : SKSpriteNode?

     let moveAsteroidDown = SKAction.repeatForever(SKAction.moveBy(x: 0, y: -1, duration: 0.01))
     let rotateAsteroid = SKAction.repeatForever(SKAction.rotate(byAngle: 25, duration: 5))

     let asteroidXpos = randomNum(high:  self.frame.size.width/2, low: -1 * self.frame.size.width/2)
     let asteroidYpos = randomNum(high:  2.5*self.frame.size.height, low: self.frame.size.height/2)
     let asteroidOrigin : CGPoint = CGPoint(x: asteroidXpos, y: asteroidYpos)

     asteroid = SKSpriteNode(imageNamed: possibleAsteroidImage[Int(arc4random_uniform(4))])
     asteroid?.scale(to: CGSize(width: player.size.height, height: player.size.height))
     asteroid?.position = asteroidOrigin
     asteroid?.run(moveAsteroidDown)
     asteroid?.run(rotateAsteroid)
     let asteroidRadius : CGFloat = (asteroid?.size.width)!/2

     asteroid?.physicsBody? = SKPhysicsBody(rectangleOf: (asteroid?.size)!)
     asteroid?.physicsBody?.categoryBitMask = asteroidCategory
     asteroid?.physicsBody?.affectedByGravity = false
     asteroid?.physicsBody?.isDynamic = false
     asteroid?.physicsBody?.allowsRotation = false

     asteroid?.physicsBody?.categoryBitMask = asteroidCategory
     asteroid?.physicsBody?.collisionBitMask = 0
     asteroid?.physicsBody?.contactTestBitMask = shipCategory

     asteroidArray.append(asteroid!)
     self.addChild(asteroid!)
}

我创建了13个这样的精灵

        for _ in 0...13 {
        CreateNewAsteroid()
    }

Answer 1

与其将SKSpriteNode小行星作为可选对象，还应使其成为非可选对象，以免通过删除?中的var asteroid : SKSpriteNode?成为空值

所以您想放var asteroid : SKSpriteNode

进行此更改后，会出现一些错误，告诉您删除一些!和?（当然，请务必删除它们）。

然后转到您的GameViewController.swift文件，并在view.showsPhysics = true下添加行view.showsNodeCount = true

完成后，您应该在精灵周围看到一个绿色的轮廓。

物理体不是只显示一个精灵？

1 个答案: