ios - SceneKit SCNNode跟随触摸运动

我试图让“球体”节点仅跟随手指在屏幕上的x轴方向运动，而不影响球体的y或z值。我不确定是否应该对物理物体施加力或使用SCNAction对其进行移动。球体将在占据屏幕宽度的多维数据集节点上反弹。到目前为止，我最大的问题是弄清楚在手势功能中应包含什么内容。这是我要复制的内容的一个示例，用户在屏幕上滑动手指，球镜像其位置。

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {

    for t in touches {

        let touchLocation = t.location(in: self.view)
        let touchCoordinatesX = (touchLocation.x - self.scnView.frame.width / 2)
        ballNode.position.x = Float(touchCoordinatesX/75)
    }
}

上面的代码有些起作用，当我在屏幕上拖动手指时，y位置会跳出来，并且即使我的代码从不编辑球的y值，它也会迅速快速地上下移动。每次我在屏幕上拖动时，将球的y位置添加到场景的根节点时，它的y位置都会重置为其原始值。


根据您的回答，这就是我所使用的，并且正是我所需要的。

@objc func handlePan(recognizer: UIPanGestureRecognizer)
{
    currentLocation = recognizer.location(in: self.view)

    let touchCoordinatesX = (currentLocation.x - self.scnView.frame.width / 2)



   if recognizer.state == .changed

   {

    ballNode.position.x = Float(touchCoordinatesX/75)
    ballNode.position.y = ballNode.presentation.position.y

    }

}

最佳答案

尝试handlePan并设置/保存dragMode状态变量。下面的代码是我用来选择面板和扫视屏幕的代码，因此其中包含一些额外的代码，但是我认为您可以根据需要进行修改。在您的情况下，我的“跨越屏幕”应该类似于您将球拖向指尖的需要。

如果将您的球对象在dragChanges（）中设置为currentLocation.x，则它应在您的指尖上精确对齐，并且响应应迅速发生。根据您的图片，我的猜测是您希望稍稍延迟一下，以便更加真实。如果是这种情况，我建议您添加一个计时器并处理一小列已保存的X位置队列，以使其以较小的增量到达您的指尖。

希望能有所帮助。

//**************************************************************************
    @objc func handlePan(recognizer: UIPanGestureRecognizer)
    {
        currentLocation = recognizer.location(in: gameScene)
        let getLocation: CGPoint = recognizer.location(in: gameScene)
        let panHitTestResults = gameScene.hitTest(getLocation, options: hitTestOptions)

        if(data.gameState == .endWave || data.gameState == .endGame ||
            data.gameState == .defenseAdd || data.gameState == .defenseUpgrade)
        {
            dragMode = .none
            selectorActive = false
            lastPanelSelected = ""
            return
        }

        // State Begins
        if recognizer.state == UIGestureRecognizerState.began
        {
            dragMode = .drag
            beginLocation = recognizer.location(in: gameScene)
            data.panX = currentLocation.x
            data.lastMouseX = Float(beginLocation.x)
            data.lastMouseY = Float(beginLocation.y)
            dragBegins(vRecognizer: recognizer)
            selectorActive = false
        }
        // State Changes
        if(recognizer.state == UIGestureRecognizerState.changed)
        {
            dragChanges(vRecognizer: recognizer)

            if(data.gameState == .run && dragMode == .drag)
            {
                // If we were selecting cursor and want to cancel, just touch with 2 fingers
                if(recognizer.numberOfTouches == 2)
                {
                    dragMode = .none
                    selectorActive = false
                    grid.cancelCursor()
                    return
                }
                for vHit in panHitTestResults
                {
                    if(vHit.node.name?.prefix(5) == "Panel")
                    {
                        selectorActive = true
                        lastPanelSelected = vHit.node.name!
                        data.panelSelected = lastPanelSelected
                        let _ = grid.selectCursor()
                        return
                    }
                }
            }
        }

        if(recognizer.state == UIGestureRecognizerState.ended)
        {
            dragEnds(vRecognizer: recognizer)
            dragMode = .none

            if(selectorActive == true)
            {
                gameControl.selectPanel(vPanel: lastPanelSelected)
                lastPanelSelected = ""
                selectorActive = false
                return
            }
        }
    }
    //**************************************************************************
    func dragBegins(vRecognizer: UIPanGestureRecognizer)
    {
        if(data.gameState == .run)
        {
            if(vRecognizer.numberOfTouches == 2) { dragMode = .strafe }
        }
    }
    //**************************************************************************
    func dragChanges(vRecognizer: UIPanGestureRecognizer)
    {
        if(data.gameState == .run)
        {
            if(dragMode == .strafe && vRecognizer.numberOfTouches == 1)
            {
                dragMode = .none
                return
            }

            switch(dragMode)
            {
            case .strafe:
                gNodes.camera.strafe(vX: Float(currentLocation.x), vY: Float(currentLocation.y))
                break
            case .none:
                break
            default:
                break
            }
        }
    }
    //**************************************************************************
    func dragEnds(vRecognizer: UIPanGestureRecognizer)
    {
        if(data.gameState == .run)
        {
            switch(dragMode)
            {
            case .strafe:
                break
            default:
                break
            }
        }
        dragMode = .none
    }

关于ios - SceneKit SCNNode跟随触摸运动，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/53255523/