Question

谢谢你看看这个。我确信这是非常基本的东西。我是初学者。

我正在尝试使用平移手势在SceneKit视图中旋转立方体。到目前为止，我已经成功地将这个示例应用程序加载到我的iPad上并在y轴上平移我的手指以在x轴上旋转立方体，或者沿着屏幕x轴平移以沿着y轴旋转立方体。 / p>

目前，我注意到最后添加到sceneView的手势识别器是有效的。我的问题是如何让立方体响应x平移手势然后响应平移手势，反之亦然。

以下是我到目前为止编写的代码：

import UIKit
import SceneKit

class ViewController: UIViewController {

  //geometry
  var geometryNode: SCNNode = SCNNode()

  //gestures
  var currentYAngle: Float = 0.0
  var currentXAngle: Float = 0.0

  override func viewDidLoad() {
    super.viewDidLoad()

    sceneSetup()  
  }

  func sceneSetup () {
    //setup scene
    let scene = SCNScene()
    let sceneView = SCNView(frame: self.view.frame)
    self.view.addSubview(sceneView)

    //add camera
    let camera = SCNCamera()
    let cameraNode = SCNNode()
    cameraNode.camera = camera
    cameraNode.position = SCNVector3(x: 0.0, y: 0.0, z: 5.0)

    //add light
    let light = SCNLight()
    light.type = SCNLightTypeOmni
    let lightNode = SCNNode()
    lightNode.light = light
    lightNode.position = SCNVector3(x: 1.5, y: 1.5, z: 1.5)

    //add cube
    let cubeGeometry = SCNBox(width: 1.0, height: 1.0, length: 1.0, chamferRadius: 0.0)
    let boxNode = SCNNode(geometry: cubeGeometry)

    scene.rootNode.addChildNode(lightNode)
    scene.rootNode.addChildNode(cameraNode)
    scene.rootNode.addChildNode(boxNode)

    geometryNode = boxNode

    //add recognizers
    let panXRecognizer = UIPanGestureRecognizer(target: self, action: "rotateXGesture:")
    let panYRecognizer = UIPanGestureRecognizer(target: self, action: "rotateYGesture:")
    sceneView.addGestureRecognizer(panXRecognizer)
    sceneView.addGestureRecognizer(panYRecognizer)

    sceneView.scene = scene
  }

  func rotateXGesture (sender: UIPanGestureRecognizer) {
    let translation = sender.translationInView(sender.view)
    var newXAngle = (Float)(translation.y)*(Float)(M_PI)/180.0
    newXAngle += currentXAngle

    geometryNode.transform = SCNMatrix4MakeRotation(newXAngle, 1, 0, 0)

    if(sender.state == UIGestureRecognizerState.Ended) {
      currentXAngle = newXAngle
    }
  }

  func rotateYGesture (sender: UIPanGestureRecognizer) {
    let translation = sender.translationInView(sender.view)
    var newYAngle = (Float)(translation.x)*(Float)(M_PI)/180.0
    newYAngle += currentYAngle

    geometryNode.transform = SCNMatrix4MakeRotation(newYAngle, 0, 1, 0)

    if(sender.state == UIGestureRecognizerState.Ended) {
      currentYAngle = newYAngle
    }
  }
}

Answer 1

将您当前的两个手势合二为一。这是我正在使用的代码的相关部分：

func panGesture(sender: UIPanGestureRecognizer) {
    let translation = sender.translationInView(sender.view!)

    var newAngleX = (Float)(translation.y)*(Float)(M_PI)/180.0
    newAngleX += currentAngleX
    var newAngleY = (Float)(translation.x)*(Float)(M_PI)/180.0
    newAngleY += currentAngleY

    baseNode.eulerAngles.x = newAngleX
    baseNode.eulerAngles.y = newAngleY

    if(sender.state == UIGestureRecognizerState.Ended) {
        currentAngleX = newAngleX
        currentAngleY = newAngleY
    }
}

这是一个缩放的手势：

func pinchGesture(sender: UIPinchGestureRecognizer) {
    let zoom = sender.scale
    var z = cameraNode.position.z  * Float(1.0 / zoom)
    z = fmaxf(zoomLimits.min, z)
    z = fminf(zoomLimits.max, z)

    cameraNode.position.z = z
}

编辑：我发现了一种更好的旋转模型的方法。在顶部的panGesture代码中，x轴在围绕y旋转时会旋转。这意味着如果围绕y旋转180°，围绕x的旋转与手指运动相反。该方法还将运动限制为两个自由度。链接到下面的方法，即使它不直接影响z轴，不知何故似乎允许三个自由度。它还使所有垂直滑动在逻辑方向上围绕x旋转。 How to rotate object in a scene with pan gesture - SceneKit

Answer 2

您设置两个手势识别器的方式是相同的，它们都会针对相同的事件触发（这就是为什么要添加的最后一个事件占主导地位）。平底锅内无法控制将其专门限制为垂直或水平平底锅。相反，请考虑分析平移的方向，然后根据哪个更大的方式决定是否以某种方式旋转手势。

具有多个UIPanGestureRecognizers的SceneKit立方体旋转

2 个答案: