【发布时间】：2017-11-18 09:28:05
【问题描述】：
我正在尝试我的第一个 SceneKit 应用。我的目标是模拟地球表面的视图，并能够将设备的摄像头指向任何方向并在摄像头视图上叠加信息。
首先，我只是想让 SceneKit 相机视图与设备的方向匹配。为了验证它是否按预期工作，我在特定的纬度和经度坐标处添加了一堆球体。
除了一个重要问题外，一切正常。该视图从它应该显示的内容向左/右（东/西）镜像。我花了几个小时尝试调整相机的不同排列。
下面是我完整的测试应用视图控制器。我无法找出正确的更改组合以使场景正确渲染。北极的球体是正确的。在我目前的经度下，从北极延伸到赤道的球体线正如预期的那样出现在头顶。这是不正确的球体的其他线。它们从它们应有的东西向东/向西镜像，就好像镜子在我自己的经度上一样。
如果您想测试此代码，请使用 SceneKit 创建一个新的游戏项目。将模板 GameViewController.swift 文件替换为以下文件。您还需要将“Privacy - Location When In Use Description”键添加到 Info.plist。我还建议调整for lon in ... 行，使数字以您自己的经度开始或结束。然后您可以看到球体是否被绘制在显示屏的正确部分。这可能还需要对UIColor(hue: CGFloat(lon + 104) * 2 / 255.0 颜色进行轻微调整。
import UIKit
import QuartzCore
import SceneKit
import CoreLocation
import CoreMotion
let EARTH_RADIUS = 6378137.0
class GameViewController: UIViewController, CLLocationManagerDelegate {
var motionManager: CMMotionManager!
var scnCameraArm: SCNNode!
var scnCamera: SCNNode!
var locationManager: CLLocationManager!
var pitchAdjust = 1.0
var rollAdjust = -1.0
var yawAdjust = 0.0
func radians(_ degrees: Double) -> Double {
return degrees * Double.pi / 180
}
func degrees(_ radians: Double) -> Double {
return radians * 180 / Double.pi
}
func setCameraPosition(lat: Double, lon: Double, alt: Double) {
let yaw = lon
let pitch = lat
scnCameraArm.eulerAngles.y = Float(radians(yaw))
scnCameraArm.eulerAngles.x = Float(radians(pitch))
scnCameraArm.eulerAngles.z = 0
scnCamera.position = SCNVector3(x: 0.0, y: 0.0, z: Float(alt + EARTH_RADIUS))
}
func setCameraPosition(loc: CLLocation) {
setCameraPosition(lat: loc.coordinate.latitude, lon: loc.coordinate.longitude, alt: loc.altitude)
}
// MARK: - UIViewController methods
override func viewDidLoad() {
super.viewDidLoad()
// create a new scene
let scene = SCNScene()
let scnCamera = SCNNode()
let camera = SCNCamera()
camera.zFar = 2.5 * EARTH_RADIUS
scnCamera.camera = camera
scnCamera.position = SCNVector3(x: 0.0, y: 0.0, z: Float(EARTH_RADIUS))
self.scnCamera = scnCamera
let scnCameraArm = SCNNode()
scnCameraArm.position = SCNVector3(x: 0, y: 0, z: 0)
scnCameraArm.addChildNode(scnCamera)
self.scnCameraArm = scnCameraArm
scene.rootNode.addChildNode(scnCameraArm)
// create and add an ambient light to the scene
let ambientLightNode = SCNNode()
ambientLightNode.light = SCNLight()
ambientLightNode.light!.type = .ambient
ambientLightNode.light!.color = UIColor.darkGray
scene.rootNode.addChildNode(ambientLightNode)
// retrieve the SCNView
let scnView = self.view as! SCNView
// set the scene to the view
scnView.scene = scene
//scnView.pointOfView = scnCamera
// Draw spheres over part of the western hemisphere
for lon in stride(from: 0, through: -105, by: -15) {
for lat in stride(from: 0, through: 90, by: 15) {
let mat4 = SCNMaterial()
if lat == 90 {
mat4.diffuse.contents = UIColor.yellow
} else if lat == -90 {
mat4.diffuse.contents = UIColor.orange
} else {
//mat4.diffuse.contents = UIColor(red: CGFloat(lat + 90) / 255.0, green: CGFloat(lon + 104) * 4 / 255.0, blue: 1, alpha: 1)
mat4.diffuse.contents = UIColor(hue: CGFloat(lon + 104) * 2 / 255.0, saturation: 1, brightness: CGFloat(255 - lat * 2) / 255.0, alpha: 1)
}
let ball = SCNSphere(radius: 100000)
ball.firstMaterial = mat4
let ballNode = SCNNode(geometry: ball)
ballNode.position = SCNVector3(x: 0.0, y: 0.0, z: Float(100000 + EARTH_RADIUS))
let ballArm = SCNNode()
ballArm.position = SCNVector3(x: 0, y: 0, z: 0)
ballArm.addChildNode(ballNode)
scene.rootNode.addChildNode(ballArm)
ballArm.eulerAngles.y = Float(radians(Double(lon)))
ballArm.eulerAngles.x = Float(radians(Double(lat)))
}
}
// configure the view
scnView.backgroundColor = UIColor(red: 0, green: 191/255, blue: 255/255, alpha: 1) // sky blue
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation
let auth = CLLocationManager.authorizationStatus()
switch auth {
case .authorizedWhenInUse:
locationManager.startUpdatingLocation()
case .notDetermined:
locationManager.requestWhenInUseAuthorization()
default:
break
}
motionManager = CMMotionManager()
motionManager.deviceMotionUpdateInterval = 1 / 30
motionManager.startDeviceMotionUpdates(using: .xTrueNorthZVertical, to: OperationQueue.main) { (motion, error) in
if error == nil {
if let motion = motion {
//print("pitch: \(self.degrees(motion.attitude.roll * self.pitchAdjust)), roll: \(self.degrees(motion.attitude.pitch * self.rollAdjust)), yaw: \(self.degrees(-motion.attitude.yaw))")
self.scnCamera.eulerAngles.z = Float(motion.attitude.yaw + self.yawAdjust)
self.scnCamera.eulerAngles.x = Float(motion.attitude.roll * self.pitchAdjust)
self.scnCamera.eulerAngles.y = Float(motion.attitude.pitch * self.rollAdjust)
}
}
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if UIApplication.shared.statusBarOrientation == .landscapeRight {
pitchAdjust = -1.0
rollAdjust = 1.0
yawAdjust = Double.pi
} else {
pitchAdjust = 1.0
rollAdjust = -1.0
yawAdjust = 0.0
}
}
override var shouldAutorotate: Bool {
return false
}
override var prefersStatusBarHidden: Bool {
return true
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
return .landscape
}
// MARK: - CLLocationManagerDelegate methods
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
if status == .authorizedWhenInUse {
manager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
for loc in locations {
print(loc)
if loc.horizontalAccuracy > 0 && loc.horizontalAccuracy <= 100 {
setCameraPosition(loc: loc)
}
}
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
}
}
可能需要在setCameraPosition 方法和/或viewDidLoad 末尾的motionManager.startDeviceMotionUpdates 闭包的某种组合中进行更改。
【问题讨论】：
标签： ios swift core-location scenekit core-motion