物理body质量 = 0 的节点在主节点上堆叠会影响主节点的跳跃高度

Question

我目前正在开发一款游戏，其中有一个主playerSprite，每次我点击屏幕时都会跳转。 每隔一会儿，一个fattySprite节点就会从天而降，堆叠在playerSprite之上。 每增加一个节点堆叠，跳跃高度就会降低。 为什么跳跃高度会降低？我尝试在fattySprite节点中将各种 physicsBody 属性设置为 0，以防止这些额外的节点影响跳跃高度。

代码片段：

override func didMove(to view: SKView) {
        self.physicsWorld.contactDelegate = self
        self.anchorPoint = CGPoint(x: 0, y: 0)
        // Character creation
        self.playerSprite = PlayerNode(position: CGPoint(x: self.frame.size.width / 9, y: self.frame.size.height / 4),
                                       size: CGSize(width: self.frame.size.width / 5, height: self.frame.size.height / 10))
        self.playerSprite?.physicsBody?.categoryBitMask = playerCategory
        self.playerSprite?.physicsBody?.contactTestBitMask = playerCategory | trapCategory
        self.playerSprite?.physicsBody?.affectedByGravity = true
        self.playerSprite?.physicsBody?.restitution = 0.0
        self.playerSprite?.physicsBody?.friction = 0
        self.addChild(self.playerSprite!)
        self.playerSprite?.beginAnimation()
        // Fatties spawning
        let wait_fatty = SKAction.wait(forDuration: 3, withRange: 2)
        let spawnFatty = SKAction.run({
            let fattySprite = PlayerNode(position: CGPoint(x: self.frame.size.width / 9, y: self.frame.size.height),
                                         size: CGSize(width: self.frame.size.width / 5, height: self.frame.size.height / 10))
            fattySprite.physicsBody?.categoryBitMask = self.fattiesCategory
            fattySprite.physicsBody?.contactTestBitMask = self.fattiesCategory | self.playerCategory
            fattySprite.physicsBody?.mass = 0
            fattySprite.physicsBody?.allowsRotation = false
            fattySprite.physicsBody?.linearDamping = 0
            fattySprite.physicsBody?.angularDamping = 0
            fattySprite.physicsBody?.restitution = 0.0
            fattySprite.physicsBody?.friction = 0
            self.addChild(fattySprite)
        })
        let fattySequence = SKAction.sequence([wait_fatty, spawnFatty])
        self.run(SKAction.repeatForever(fattySequence))
    }
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if self.playerSprite?.action(forKey: "jump") == nil { // check that there's no jump action running
            //self.playerSprite?.physicsBody?.velocity = CGVector(dx: 0, dy: 500 )
            self.playerSprite?.physicsBody?.applyImpulse(CGVector(dx: 0, dy: 500))
        }
    }

Answer 1

在给它一个值之前，你必须创建一个物理体。在所有这些对fattySprite.physicsbody的呼吁中？您正在尝试将值分配给 nil 变量。

这样做： fattySprite.physicsbody = SKPhysicsbody(rectangleOf： fattySprite.size(

，然后分配所有物理属性。我看不出你是如何构建你的播放器节点的，可能还有更合适的物理体初始化函数。查看文档:)https://developer.apple.com/reference/spritekit/skphysicsbody