ios - 如果 HitTest 失败，则将平移手势传递给默认相机 Controller

Question

我有一个 SceneKit SCNView，我想在上面附加一个平移手势识别器。这将执行一个 hitTest 来确定用户是否触摸了我场景中的特定对象。但是，如果此点击测试失败(用户没有特别触摸任何东西)，那么我想将该触摸传递给默认相机 Controller 。

目前，添加我自己的平移手势识别器似乎会覆盖默认相机 Controller 并阻止其工作。

let scnView = SCNView()
// Configure scnView with my geometry etc
// ...

let panGesture = UIPanGestureRecognizer(target: context.coordinator,
                                             action: #selector(panned))
scnView.addGestureRecognizer(panGesture)
scnView.allowsCameraControl = true

目前我的手势识别器是这样开始的:

@objc func panned(gesture: UIPanGestureRecognizer) {
            let sceneView : SCNView = gesture.view as! SCNView
            let point = gesture.location(in: sceneView)

            switch gesture.state {
            case .began:

                guard let hitNodeResult = sceneView.hitTest(point, options: [:]).first else { return }
                // Rather than just 'return' I suspect I want to do something here...

             // ....
}

Answer 1

三件事最终帮助我解决了这个问题:

1。同时处理两个平移手势

首先，我必须在我自己的平移手势上添加一个手势识别器委托(delegate):

myPanGesture.delegate = self

像这样的委托(delegate)方法:

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true;
}

2。要求我们的平移手势在相机启动前失败

接下来我找到了控制相机的内置平移手势识别器，并告诉它需要我的平移手势失败才能起作用:

let panGestures = scnView.gestureRecognizers!.filter { $0 is UIPanGestureRecognizer } as! [UIPanGestureRecognizer]
if (!panGestures.isEmpty) {
    let cameraPanGesture = panGestures.first!
    cameraPanGesture.require(toFail: myPanGesture)
}

3。将失败的 HitTest 视为手势识别器“失败”

@objc func panned(gesture: UIPanGestureRecognizer) {
        let sceneView : SCNView = gesture.view as! SCNView
        let point = gesture.location(in: sceneView)

        switch gesture.state {
        case .began:
            guard let hitNodeResult = sceneView.hitTest(point, options: [:]).first else {
                // Cancel the gesture so that the camera pan kicks in
                gesture.state = .failed
                return
            }

            // .....

然后，嘿，很快，它起作用了!现在，您可以通过平移场景中的对象来旋转场景，或​​者在点击对象时平移对象。