ARKit

AR只是辅助功能的话 项目里面一定使用ARWorldTrackingConfiguration.isSupported 用各个配置下面的isSupported来判断用户的iOS设备是否支持AR功能
AR功能是主要功能的话 需要在info.plist里面设置 如图1

图1.png

创建静态AR

1.新建一个scn后缀的文件 把里面的内容删掉 拖进去一个shape
2.去https://www.solarsystemscope.com/textures/地址下载质地
3.修改scn里面的位置 旋转角度 大小 修改他的质地
4.在viewController里面修改 let scene = SCNScene(named: "art.scnassets/sphere.scn")!的名称
即可展示静态AR

创建动态AR

创建3D球体

        //几何体 3D球体
        let sphere = SCNSphere(radius: 0.2)
        //贴纸
        sphere.firstMaterial?.diffuse.contents = UIImage(named: "art.scnassets/8k_earth_daymap.jpg")
        //结点 创建结点 用于渲染这个3D模型
        let node = SCNNode(geometry: sphere)
        //规定节点在现实环境中的三维位置
        node.position = SCNVector3(0, 0, -0.5)
        //rootNode 相当于在scnassets中的一个.scn文件 addChildNode 加子节点用于渲染并显示出来
        sceneView.scene.rootNode.addChildNode(node)

如何把obj文件转化为usdz文件

1.打开终端
2.输入xcrun usdz_converter obj文件的路径 转化完之后的路径(取名为usdz的后缀)
3.然后如图2 转化为scn文件(xcode里面)

图2.png

平面检测

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Set the view's delegate
        sceneView.delegate = self
        
        // Show statistics such as fps and timing information
        sceneView.showsStatistics = true

        //是否自动给模型打光
        sceneView.automaticallyUpdatesLighting = true
        
        //显示视频统计信息 - 用于调试
        sceneView.showsStatistics = true
        
        sceneView.debugOptions = .showFeaturePoints
   }

   override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        // Create a session configuration
        //ARWorldTrackingConfiguration 跟现实环境融为一体
        let configuration = ARWorldTrackingConfiguration()

        //平面检测 水平平面
        configuration.planeDetection = .horizontal
        // Run the view's session
        sceneView.session.run(configuration)
    }

     // MARK: - ARSCNViewDelegate
    //ARAnchor 一个包含真实世界位置  方向 大小 等信息的东西 可用来放3D模型以便和真实世界无缝衔接
    //当设定了configuration里面的平面检测之后 session会自动添加到ARAnchor(也就是说系统会自动帮我们检测平面 并把检测到的平面的大小 位置 方向等信息放在ARAnchor这个参数里面)
    func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
        //筛选出检测平面的那部分anchor-anchor是虚拟的 要展示出来的话 必须添加节点
        if let planeAnchor = anchor as? ARPlaneAnchor {
            //设定几何体(一个平面控件) 并加上贴纸
            let plane = SCNPlane(width: CGFloat(planeAnchor.extent.x), height: CGFloat(planeAnchor.extent.z))
            guard let material = plane.firstMaterial else { return }
            material.diffuse.contents = UIColor.init(white: 1, alpha: 0.5)
            //根据这个几何体 创建节点并设定位置
            let planeNode = SCNNode(geometry: plane)
            planeNode.simdPosition = planeAnchor.center//三维位置向量 (包括位置和方向的量)
            planeNode.eulerAngles.x = -.pi/2
            //加到空节点b中以便显示出来
            node.addChildNode(planeNode)
        }
    }

根据平面 用户点击点 放置模型

    //当用户触摸到真实环境中的水平面的时候才放入茶壶
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        
        //获取点击的二维坐标
        guard let location = touches.first?.location(in: sceneView) else{return}
        //转换为三维坐标
        guard let result = sceneView.hitTest(location, types: .existingPlaneUsingExtent).first else{return}
        let position = result.worldTransform.columns.3
        
        //根据这个三维坐标放置一个茶壶3D模型
        guard let scene = SCNScene(named: "art.scnassets/teapot.scn") else{return}
        guard let teapotNode = scene.rootNode.childNode(withName: "Teapot", recursively: true) else{return}
        teapotNode.position = SCNVector3(position.x, position.y, position.z)
        //这里一定要用sceneView 找到rootNode
        sceneView.scene.rootNode.addChildNode(teapotNode)
        
    }

测距仪

     var nodes: [SCNNode] = []
     override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        
        if nodes.count >= 2 {
            for node in nodes {
                node.removeFromParentNode()
            }
            nodes = []
        }
        
        guard let location = touches.first?.location(in: sceneView) else{return}
        guard let result = sceneView.hitTest(location, types: .featurePoint).first else{return}
        let position =  result.worldTransform.columns.3
        
        let sphere = SCNSphere(radius: 0.005)
        sphere.firstMaterial?.diffuse.contents = UIColor.yellow
        let node = SCNNode(geometry: sphere)
        node.position = SCNVector3(x: position.x, y: position.y, z: position.z)
        
        sceneView.scene.rootNode.addChildNode(node)
        
        nodes.append(node)
        if nodes.count >= 2 {
            let p1 = nodes[0].position
            let p2 = nodes[1].position
            let distance = abs(sqrt(pow(p1.x-p2.x, 2) + pow(p1.y-p2.y, 2) + pow(p1.z-p2.z, 2)))
            print(distance)
        }
    }

图像识别

     override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        // Create a session configuration
        let configuration = ARWorldTrackingConfiguration()

        configuration.detectionImages = ARReferenceImage.referenceImages(inGroupNamed: "Pake Cards", bundle: nil)
        configuration.maximumNumberOfTrackedImages = 1
        // Run the view's session
        sceneView.session.run(configuration)
    }

    // MARK: - ARSCNViewDelegate
    func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
        
        DispatchQueue.main.async {
        
            guard let imageARAnchor = anchor as? ARImageAnchor else { return }
            let planeNode = SCNNode(geometry: SCNPlane(width: imageARAnchor.referenceImage.physicalSize.width, height: imageARAnchor.referenceImage.physicalSize.height))
            planeNode.opacity = 0.25
            //逆时针旋转
            planeNode.eulerAngles.x = -.pi/2
            
            guard let eeveeNode = SCNScene(named: "art.scnassets/eevee.scn")?.rootNode.childNode(withName: "eevee", recursively: true) else { return }
            
            node.addChildNode(planeNode)
            node.addChildNode(eeveeNode)
        }
        
    }