ios - 向右滑动时如何旋转到 3d 立方体的另一个面

Question

我使用 SceneKit 创建了一个 3d 立方体，并添加了一个手势来识别向右滑动。但是，我不知道如何在向右滑动时将立方体旋转到另一个面。我不希望立方体在滑动时连续旋转，只移动到右侧的另一个面。抱歉造成任何混淆。

这是我创建立方体的代码:

import UIKit
import SceneKit

class ViewController: UIViewController {
// UI
@IBOutlet weak var geometryLabel: UILabel!
@IBOutlet weak var sceneView: SCNView!
// Geometry
var geometryNode: SCNNode = SCNNode()

// Gestures
var currentAngle: Float = 0.0

// MARK: Lifecycle
override func viewDidLoad() {
  super.viewDidLoad()

}

override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)

// MARK: Scene

sceneSetup()


}

func sceneSetup() {

    let scene = SCNScene()
    sceneView.scene = scene
    sceneView.allowsCameraControl = false
    sceneView.autoenablesDefaultLighting = true

    let cameraNode = SCNNode()
    cameraNode.camera = SCNCamera()
    cameraNode.position = SCNVector3Make(0, 0, 25)
    scene.rootNode.addChildNode(cameraNode)

    var geometries = [
        SCNBox(width: 8.0, height: 8.0, length: 8.0, chamferRadius: 1.0)
    ]

    var materials = [SCNMaterial]()

    for i in 1...6 {
        let material = SCNMaterial()

        if i == 1 { material.diffuse.contents = UIColor(red:0.02, green:0.98, blue:0.98, alpha:1.0) }
        if i == 2 { material.diffuse.contents = UIColor(red:0.02, green:0.98, blue:0.98, alpha:1.0) }
        if i == 3 { material.diffuse.contents = UIColor(red:0.02, green:0.98, blue:0.98, alpha:1.0) }
        if i == 4 { material.diffuse.contents = UIColor(red:0.02, green:0.98, blue:0.98, alpha:1.0) }
        if i == 5 { material.diffuse.contents = UIColor(red:0.02, green:0.98, blue:0.98, alpha:1.0) }
        if i == 6 { material.diffuse.contents = UIColor(red:0.02, green:0.98, blue:0.98, alpha:1.0) }

        materials.append(material)
    }

    for i in 0..<geometries.count {
        let geometry = geometries[i]
        let node = SCNNode(geometry: geometry)

        node.geometry?.materials = materials

        scene.rootNode.addChildNode(node)
    }


    let swipeRight: UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(respondToSwipeGesture(gesture:)))
    swipeRight.direction = .right
    sceneView.addGestureRecognizer(swipeRight)


}

识别时右滑手势功能:

func respondToSwipeGesture(gesture: UIGestureRecognizer) {


    if let swipeGesture = gesture as? UISwipeGestureRecognizer {


        switch swipeGesture.direction {

            case UISwipeGestureRecognizerDirection.right:

                print("Swiped Right")

            default:

                break
        }
    }
}

Answer 1

您需要使用 SCNAction.rotate 获取节点旋转的当前 w 值并添加您想要的角度量，使用这 2 个扩展来转换为弧度和从弧度，替换我的self.shipNode 由你的立方体节点，并根据需要更改轴，考虑到 SCNVector4Make 句子中的第一个 0 是 X 轴

这是一个例子

extension Int {
    var degreesToRadians: Double { return Double(self) * .pi / 180 }
    var radiansToDegrees: Double { return Double(self) * 180 / .pi }
}

extension FloatingPoint {
    var degreesToRadians: Self { return self * .pi / 180 }
    var radiansToDegrees: Self { return self * 180 / .pi }
}

@objc func handleTap(_ gestureRecognize: UIGestureRecognizer) {
    //here we rotate the ship node 30 grades in the Y axis each time
    self.shipNode?.runAction(SCNAction.rotate(toAxisAngle: SCNVector4Make(0, 1, 0, (self.shipNode?.rotation.w)! + Float(30.degreesToRadians)), duration: 1))
}

要向下旋转你只需要改变旋转轴 你可以用这个

- (void) handleTap:(UIGestureRecognizer*)gestureRecognize
{

     [self.ship runAction:[SCNAction rotateToAxisAngle:SCNVector4Make(1, 0, 0, [self getRadiansFromAngle:[self getAngleFromRadian:self.ship.rotation.w] + 30]) duration:1]];
}

已更新 使用您的代码 您需要使用 SCNAction.rotate(by: #Float, around: #SCNVector3, duration: #duration) 方法，下面是您的要求的完整代码

@objc func respondToSwipeGesture(gesture: UIGestureRecognizer) {


        if let swipeGesture = gesture as? UISwipeGestureRecognizer {


            switch swipeGesture.direction {

                case UISwipeGestureRecognizerDirection.right:

                    print("Swiped Right")

                geometryNode.runAction(SCNAction.rotate(by: CGFloat(90.degreesToRadians), around: SCNVector3Make(0, 1, 0), duration: 0.2))


                case UISwipeGestureRecognizerDirection.left:

                    print("Swiped Left")
                    geometryNode.runAction(SCNAction.rotate(by: CGFloat(-90.degreesToRadians), around: SCNVector3Make(0, 1, 0), duration: 0.2))

                case UISwipeGestureRecognizerDirection.down:

                    print("Swiped Down")
                   geometryNode.runAction(SCNAction.rotate(by: CGFloat(90.degreesToRadians), around: SCNVector3Make(1, 0, 0), duration: 0.2))
                default:

                    break
            }
        }
    }