ios - 如何在同类节点之间不发生碰撞

Question

我正在尝试制作一款带有玩家方 block 和一些障碍方 block 的游戏。玩家可以与障碍物发生碰撞，但障碍物不应相互碰撞，而应相互“穿过”。我的位掩码有以下枚举:

enum bitMask: UInt32 {
    case player = 1
    case obstacle = 2
    case frame = 4
}

这就是我定义播放器 block 的方式:

let player = SKSpriteNode(imageNamed: "yellow-square")
player.physicsBody = SKPhysicsBody(texture: player.texture!, size: player.frame.size)
player.physicsBody!.dynamic = false
player.physicsBody!.categoryBitMask = bitMask.player.rawValue
player.physicsBody!.contactTestBitMask = bitMask.obstacle.rawValue
player.physicsBody!.collisionBitMask = 0
addChild(player)
player.physicsBody!.contactTestBitMask = bitMask.obstacle.rawValue
player.physicsBody!.collisionBitMask = bitMask.frame.rawValue

我的障碍物(在 for 循环中):

let obstacle = SKSpriteNode(imageNamed: "black-square")
obstacle.physicsBody = SKPhysicsBody(texture: obstacle.texture!, size: obstacle.frame.size)
boundaryNode.addChild(obstacle)
obstacle.physicsBody!.applyImpulse(CGVectorMake(-15, -10))
obstacle.physicsBody!.categoryBitMask = bitMask.obstacle.rawValue
obstacle.physicsBody!.contactTestBitMask = bitMask.player.rawValue

还有我的联系方式:

func didBeginContact(contact: SKPhysicsContact) {
    let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask
    switch(contactMask) {
        case bitMask.player.rawValue | bitMask.obstacle.rawValue:
            let yourTimeNode = contact.bodyB.node
            yourTimeNode?.physicsBody?.allowsRotation = false

            let firstNode = contact.bodyA.node
            firstNode?.physicsBody?.allowsRotation = false

            print("Collision")
        default:
            return
    }
}

目前每个 block 都相互碰撞，我不知道如何关闭障碍物之间的碰撞并保持障碍物和玩家 block 之间的碰撞。

Answer 1

您的代码中有几处需要更改。首先你应该像这样制作位掩码

struct BitMask {
     static let player: UInt32 = 0x1 << 0
     static let obstacle: UInt32 = 0x1 << 1
     static let frame: UInt32 = 0x1 << 2
}

这样你只需要将最后一个数字增加 1，如果你开始添加更多的位掩码，这会让你的生活更轻松。比你这样调用它

...categoryBitMask = BitMask.obstacle // no need for rawValue

你应该把你的联系方式改成这样

/// Did Begin Contact
func didBeginContact(contact: SKPhysicsContact) {
    var firstBody: SKPhysicsBody
    var secondBody: SKPhysicsBody

    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if (firstBody.categoryBitMask == BitMask.player) && (secondBody.categoryBitMask == BitMask.obstacle) {
        // do your thing 
    }
}

最后在您的播放器和障碍物代码中，首先在播放器代码中您重复了 2 个值 (contactBitMask/categoryBitMask)，因此删除它们。其次，你的障碍物相互碰撞的原因是你没有为你的障碍物设置 collisionBitMask。这使它成为默认值 0xFFFFFFFF，这意味着所有位都已设置并且它将与所有内容交互。要修复它，请将其添加到障碍代码中

 obstacle.physicsBody!.collisionBitMask = BitMask.player

现在障碍物只会与玩家发生碰撞。