如何使用平移手势旋转场景中的对象 - SceneKit

Question

我想用Scene套件创建一个应用来解决Rubix Cube.我有自己的dae文件用于多维数据集.这是我在viewDidLoad中的设置代码

    let myscene = SCNScene(named: "Rubik1.scnassets/Rubiks_Cube.dae")
    scene.rootNode.addChildNode((myscene?.rootNode)!)

    // retrieve the SCNView
    let scnView = self.view as! SCNView

    // set the scene to the view
    scnView.scene = scene

    geometryNode = (scnView.scene?.rootNode.childNodeWithName("Cube",recursively: true))!

    let panRecognizer = UIPanGestureRecognizer(target: self, action: "panGesture:")
    scnView.addGestureRecognizer(panRecognizer)

在识别平移手势以旋转立方体时

func panGesture(gestureRecognize: UIPanGestureRecognizer){

    let translation = gestureRecognize.translationInView(gestureRecognize.view!)

    let x = Float(translation.x)
    let y = Float(-translation.y)

    let anglePan = sqrt(pow(x,2)+pow(y,2))*(Float)(M_PI)/180.0

    var rotationVector = SCNVector4()
    rotationVector.x = -y
    rotationVector.y = x
    rotationVector.z = 0
    rotationVector.w = anglePan

    geometryNode.rotation = rotationVector

    //geometryNode.transform = SCNMatrix4MakeRotation(anglePan, -y, x, 0)

    if(gestureRecognize.state == UIGestureRecognizerState.Ended) {
        //
    }
}

上面的代码不保留以前的平移手势.我如何使用"rotationvector"或

SCNMatrix4MakeRotation(anglePan, -y, x, 0)

旋转立方体

Answer 1

问题已经解决了

if(gestureRecognize.state == UIGestureRecognizerState.Ended) {

    let currentPivot = geometryNode.pivot
    let changePivot = SCNMatrix4Invert( geometryNode.transform)

    geometryNode.pivot = SCNMatrix4Mult(changePivot, currentPivot)

    geometryNode.transform = SCNMatrix4Identity
}

Answer 2

如果对象原始位置不是(0,0,0),则此解决方案有效.

    if(gestureRecognize.state == UIGestureRecognizerState.Ended) {
       let currentPivot = geometryNode.pivot
       let currentPosition = geometryNode.position
       let changePivot = SCNMatrix4Invert(SCNMatrix4MakeRotation(geometryNode.rotation.w, geometryNode.rotation.x, geometryNode.rotation.y, geometryNode.rotation.z))

       geometryNode.pivot = SCNMatrix4Mult(changePivot, currentPivot)
       geometryNode.transform = SCNMatrix4Identity
       geometryNode.position = currentPosition
    }

但我不明白为什么我们将transform或rotation的反转值赋给changePivot.它是否正确,我们正在尝试将枢轴旋转到我们当前的旋转值,并将.transform属性设置为单位矩阵,它将节点重置为枢轴值.我们没有看到任何变化,因为枢轴已经具有与我们的节点相同的值.但是为什么我们使用反转值,通常你用它来将某些东西旋转回原点.有人可以告诉我,我在哪里错了吗？