如何在Xcode ArKit中创建掉落效果

Question

当我点击屏幕或摇动时，我试图创造一种手工掷骰子的效果。在我的参考代码中有旋转效果，以便骰子面临随机变化。我试图在骰子旋转时制作这个代码，它必须是摔倒。我的意思是它会从预定义的坐标y下降到坐标y 0。任何想法都会受到影响。

   override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first{
        let touchLocation = touch.location(in: sceneView)
        let results = sceneView.hitTest(touchLocation, types: .existingPlaneUsingExtent)
        if let hitResult = results.first{
            let diceScene = SCNScene(named: "art.scnassets/diceCollada.scn")!
            if let diceNode = diceScene.rootNode.childNode(withName: "Dice", recursively: false){


                diceNode.position = SCNVector3(
                   hitResult.worldTransform.columns.3.x,
                    hitResult.worldTransform.columns.3.y + diceNode.boundingSphere.radius,
                    hitResult.worldTransform.columns.3.z)



                let randomX = Float(arc4random_uniform(4) + 1) * (Float.pi/2)
                let randomZ = Float(arc4random_uniform(4) + 1) * (Float.pi/2)

                diceNode.runAction(
                    SCNAction.rotateBy(x: CGFloat(randomX * 3),
                                       y: 0,
                                       z: CGFloat(randomZ * 3),
                                       duration: 0.5)
                )
                 sceneView.scene.rootNode.addChildNode(diceNode)
            }

            print(hitResult)
        }

    }
}