ios - 添加 SKPhysicsJointLimit 后 SKPhysicsBodies 不会发生碰撞

Question

我目前有两个 SKSpriteNode，我已将 SKPhysicsBodies 添加到其中。当它们没有附加 SKJoint 时，它们会按预期发生碰撞。一旦我添加 SKPhysicsJoint，它们就会直接穿过彼此。我添加的任何关节都可以正确运行，但 SKPhysicsJointLimit 仅限制节点彼此可以分开的程度，而不是它们可以接近的程度。我该如何解决这个问题？

这是我用于关节的代码:

let joint = SKPhysicsJointLimit.joint(withBodyA: object1.physicsBody!, bodyB: object2.physicsBody!, anchorA: CGPoint(x: object1.position.x + iconController.position.x, y: object1.position.y + iconController.position.y), anchorB: CGPoint(x: object2.position.x + iconController.position.x, y: object2.position.y + iconController.position.y))
    joint.maxLength = screen.height * 0.4

physicsWorld.add(joint)

两个节点的PhysicsBody:

self.physicsBody = SKPhysicsBody(circleOfRadius: self.size.width / 2)
self.physicsBody?.allowsRotation = false
self.physicsBody?.friction = 0
self.physicsBody?.mass = 0.1

我已经使用不同的值对 SKPhysicsBody 的上述修改进行了测试，结果是相同的。

Answer 1

SKPhysicsJoint 对象连接两个物理体，以便物理世界将它们模拟在一起。您还可以使用SKPhysicJointPin:

A pin joint allows the two bodies to independently rotate around the anchor point as if pinned together.

如果您的对象在使用物理引擎添加 SKPhysicsJoint 之前工作良好，因此它们按照您的意愿和设置触发了 didBeginContact，我认为您的问题很简单一个错误的 anchor 。尝试添加:

让 skView = self.view as! SK View
skView.showsPhysics = true

到您的场景初始化代码:您将看到物理主体的轮廓，也许您会立即看到问题。

为了帮助您，我将尝试制作一个配置为相互碰撞的元素的示例:

enum CollisionTypes: UInt32 {
    case Boundaries = 1
    case Element = 2
}

class GameScene: SKScene,SKPhysicsContactDelegate {
    private var elements = [SKNode]()
    override func didMoveToView(view: SKView) {
        physicsWorld.gravity = CGVector(dx: 0, dy: 0)
        self.physicsWorld.contactDelegate = self
        let boundariesFrame = CGRectMake(20, 20, 200, 400)
        let boundaries = SKShapeNode.init(rect: boundariesFrame)
        boundaries.position = CGPointMake(350,150)
        let boundariesBody = SKPhysicsBody.init(edgeLoopFromRect: boundariesFrame)
        boundariesBody.dynamic = false
        boundariesBody.categoryBitMask = CollisionTypes.Boundaries.rawValue
        boundariesBody.contactTestBitMask = CollisionTypes.Element.rawValue
        boundaries.physicsBody = boundariesBody
        addChild(boundaries)
        for index in 0..<5 {
            let element = SKShapeNode(circleOfRadius: 10)
            let body = SKPhysicsBody(circleOfRadius: 10)
            body.linearDamping = 0
            // body.mass = 0
            body.dynamic = true
            body.categoryBitMask = CollisionTypes.Element.rawValue
            body.contactTestBitMask = CollisionTypes.Boundaries.rawValue | CollisionTypes.Element.rawValue
            body.collisionBitMask = CollisionTypes.Boundaries.rawValue | CollisionTypes.Element.rawValue
            element.physicsBody = body
            element.position = CGPoint(x: size.width / 2, y: size.height / 2 - 30 * CGFloat(index))
            elements.append(element)
            addChild(element)
        }
    }
}

希望它可以帮助您找到问题。