swift - SKPhysicsBody 碰撞不起作用

Question

下面是我的“Floor.swift”类，下面基本上是一堆墙。我有来自屏幕顶部的对象，一旦 Floor 和 SKSpriteNodes 发生碰撞，我希望 SKSpriteNode 被移除。下面是我的 Floor 类。

import Foundation
import SpriteKit

class Floor: SKNode {
    override init() {
        super.init()

        let leftWall = SKSpriteNode(color: UIColor.clear, size: CGSize(width: 5, height: 50))
        leftWall.position = CGPoint(x: 0, y: 50)
        leftWall.physicsBody = SKPhysicsBody(rectangleOf: leftWall.size)
        leftWall.physicsBody!.isDynamic = false
        self.addChild(leftWall)

        let rightWall = SKSpriteNode(color: UIColor.clear, size: CGSize(width: 5, height: 50))
        rightWall.position = CGPoint(x: 375, y: 50)
        rightWall.physicsBody = SKPhysicsBody(rectangleOf: rightWall.size)
        rightWall.physicsBody!.isDynamic = false
        self.addChild(rightWall)

        let bottomWall = SKSpriteNode(color: UIColor.clear, size: CGSize(width: 500, height: 10))
        bottomWall.position = CGPoint(x: 150, y: -5)
        bottomWall.physicsBody = SKPhysicsBody(rectangleOf: bottomWall.size)
        bottomWall.physicsBody!.isDynamic = false
        self.addChild(bottomWall)

        self.physicsBody = SKPhysicsBody(bodies: [leftWall.physicsBody!, rightWall.physicsBody!, bottomWall.physicsBody!])

        self.physicsBody?.categoryBitMask = floorCategory
        self.physicsBody?.contactTestBitMask = nailDropCategory | pointCategory | lifeCategory
        self.physicsBody?.collisionBitMask = balloonCategory
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemted")
    }
}

我在“func didBegin(_ contact: SKPhysicsContact)”下的 GameScene 类中写道:

func didBegin(_ contact: SKPhysicsContact) {        
        if (contact.bodyA.categoryBitMask == nailDropCategory | pointCategory | lifeCategory) && (contact.bodyB.categoryBitMask == floorCategory) {
           // contact.bodyB.node!.removeFromParent()
            print("COLLISION")
        }
}

如您所见，在我的 Floor 类中，我将对象设置为“self.physicsBody = SKPhysicsBody(bodies:)”以及我所有的 SKSpriteNode。但出于某种原因，我没有得到任何检测。我让我的“Floor”类成为我的 objectCategory、pointCategory、lifeCategory 的每个类上的“contactTestBitMask”。这个问题我已经坚持了一分钟了，有什么想法吗？

更新:

所以我现在正在使用下面的这段代码，它可以正常工作!唯一的问题是，默认情况下也删除了我的“balloonCategory”，我不希望它这样做。我怎样才能让它只忽略那个类别，同时充当气球的墙？

func didBegin(_ contact: SKPhysicsContact) {
        let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask

        switch contactMask {
        case balloonCategory | nailDropCategory:
            print("nailDrop and balloon have contacted.")
            contact.bodyB.node!.removeFromParent()
            self.run(SKAction.playSoundFileNamed("lostlifesound.mp3", waitForCompletion:false))
            lifeLost -= 1
        case balloonCategory | pointCategory:
            print("point and balloon have contacted.")
            contact.bodyB.node!.removeFromParent()
            totalPoints += 2
            self.run(SKAction.playSoundFileNamed("pointsound.mp3", waitForCompletion:false))
        case balloonCategory | lifeCategory:
            print("life and balloon have contacted.")
            contact.bodyB.node!.removeFromParent()
            lifeLost += 1
            self.run(SKAction.playSoundFileNamed("pointsound.mp3", waitForCompletion:false))
        default:            
            contact.bodyB.node!.removeFromParent()
            print("Removed \(String(describing: contact.bodyB.node!.name))")
        }
    }

Answer 1

听起来您会受益于为所有对象类型分配名称，如下所示:

class Balloon: SKSpriteNode {
    init() {
        super.init(texture: nil, color: .blue, size: CGSize(width: 50, height: 50))
        self.name = "balloon"
    }
}

现在，当您在开关中进行检查时，您可以在决定删除对象之前验证对象的身份。在下面的 switch 语句中查看我对 default case 所做的更改。这样，如果节点是气球，则不会被删除。物理碰撞将继续起作用。

func didBegin(_ contact: SKPhysicsContact) {
    let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask

    switch contactMask {
    case balloonCategory | nailDropCategory:
        print("nailDrop and balloon have contacted.")
        contact.bodyB.node!.removeFromParent()
        self.run(SKAction.playSoundFileNamed("lostlifesound.mp3", waitForCompletion:false))
        lifeLost -= 1
    case balloonCategory | pointCategory:
        print("point and balloon have contacted.")
        contact.bodyB.node!.removeFromParent()
        totalPoints += 2
        self.run(SKAction.playSoundFileNamed("pointsound.mp3", waitForCompletion:false))
    case balloonCategory | lifeCategory:
        print("life and balloon have contacted.")
        contact.bodyB.node!.removeFromParent()
        lifeLost += 1
        self.run(SKAction.playSoundFileNamed("pointsound.mp3", waitForCompletion:false))
    default:
        if contact.bodyB.node!.name == "balloon" {
            print("Balloon collided but we will not remove it.")
            return
        } else {
            contact.bodyB.node!.removeFromParent()
            print("Removed \(String(describing: contact.bodyB.node!.name))")
    }
}