如何使用collisionBitMask？斯威夫特/ SpriteKit

greenBall.physicsBody?.categoryBitMask = GreenBallCategory //Category is GreenBall
greenBall.physicsBody?.contactTestBitMask = RedBarCategory | WallCategory //Contact will be detected when GreenBall make a contact with RedBar or a Wall (assuming that redBar's masks are already properly set)
greenBall.physicsBody?.collisionBitMask = GreenBallCategory | RedBallCategory | WallCategory //Collision will occur when GreenBall hits GreenBall,RedBall or hits a Wall

redBall.physicsBody?.categoryBitMask = RedBallCategory //Category is RedBall
redBall.physicsBody?.contactTestBitMask = GreenBarCategory | GreenBallCategory | WallCategory //Contact will be detected when RedBall make a contact with GreenBar,GreenBall or a Wall
redBall.physicsBody?.collisionBitMask = RedBallCategory | GreenBallCategory | WallCategory //Collision will occur when RedBall meets RedBall,GreenBall or hits a Wall

let borderBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
self.physicsBody = borderBody
self.physicsBody?.friction = 0
borderBody.contactTestBitMask = RedBallCategory | GreenBallCategory //Contact will be detected when red or green ball hit the wall
borderBody.categoryBitMask = WallCategory
borderBody.collisionBitMask = RedBallCategory | GreenBallCategory // Collisions between RedBall GreenBall and a Wall will be detected

我建议您阅读约categoryBitMask的文档,这是一个面具,用于定义物理主体所属的类别：

contactTestBitMask – 一个面具,用于定义哪些类别的物体与当前物理体引起交集通知.

collisionBitmask – 一个面具,用于定义哪些类别的物理物体可以与这个物理体碰撞.

所以基本上,要设置所有这些,你应该问你自己的东西：

好吧,我有一个绿色的球,一个红色的球,和墙上的对象现场.在哪些机构我想要碰撞发生,或当我想要注册联系人？我想要一个绿色和一个红色的球相互碰撞并碰撞墙壁.不是问题我将首先正确设置类别,然后我将设置这样的碰撞位掩码：

greenBall.collisionBitMask = GreenBallCategory | RedBallCategory | WallCategory; //greenBall will collide with greenBall,redBall and a wall
redBall.collisionBitMask = GreenBallCategory | RedBallCategory | WallCategory

wall.collisionBitMask = GreenBall | RedBall

现在,我想检测一些联系人发生的时间(inBeginContact：method)…但是我不想收到所有可能的联系人的通知,而是要通知球之间的联系(球和墙之间的联系将被忽略).所以让我们设置contactTestBitMasks来实现这一点：

greenBall.contactTestBitMask = GreenBallCategory | RedBallCategory;
redBall.contactTestBitMask = GreenBallCategory | RedBallCategory;

就是这样重要的是当您不使用联系人检测时,不应设置contactTestBitMask.这是因为性能原因.如果您不需要碰撞检测,并且您只对检测到联系人感兴趣,可以设置collisionBitMask = 0.

重要：

确保您已设置物理世界的联系人委托以使用didBeginContact和didEndContact方法：

self.physicsWorld.contactDelegate = self; //where self is a current scene

希望这有帮助.