测量水平面 ARKIT [1]

1 回答

• 0

  提前知道房间的大小是很棘手的。

  但是，无法测量任何检测到的飞机的尺寸：

  每次检测到水平或垂直表面(假设您已启用它们)，都会生成一个 ARPlaneAnchor：

  当您运行启用了 planeDetection 选项的 world-tracking AR 会话时，该会话会自动将 ARKit 用 back-facing 相机检测到的每个平面的 ARPlaneAnchor 对象添加到其锚点列表中。每个平面锚提供有关估计的表面位置和形状的信息。

  在以下委托回调中调用此方法：

  func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { }
  

  因此，您可以获取 ARPlaneAnchor 的宽度，如下所示：

  func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
  
          //1. Get The Current ARPlaneAnchor
          guard let anchor = anchor as? ARPlaneAnchor else { return }
  
          //2. Log The Initial Width & Height
          print("""
              Initial Width = \(anchor.extent.x)
              Initial Height = \(anchor.extent.z)
              """)
  
   }
  

  但是，此初始解决方案存在一个问题，即 ARPlaneAnchor 通过以下回调进行更新(e.g. 它的大小已更改)：

  func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) { }
  

  因此，如果您要跟踪ARPlaneAnchor的更新大小，则需要考虑到这一点。

  让我们看看如何做到这一点：

  首先，我们创建自己的SCNNode Subclass，称为 PlaneNode，即使更新后，它们也会返回平面的大小。

  请注意，尽管我已经创建了一个子类以使其易于重用，但您无需创建一个子类即可达到相同的结果：

  class PlaneNode: SCNNode {
  
      let DEFAULT_IMAGE: String = "defaultGrid"
      let NAME: String = "PlaneNode"
      var planeGeometry: SCNPlane
      var planeAnchor: ARPlaneAnchor
  
      var widthInfo: String!
      var heightInfo: String!
      var alignmentInfo: String!
  
      //---------------
      //MARK: LifeCycle
      //---------------
  
      /// Inititialization
      ///
      /// - Parameters:
      ///   - anchor: ARPlaneAnchor
      ///   - node: SCNNode
      ///   - node: Bool
      init(anchor: ARPlaneAnchor, node: SCNNode, image: Bool, identifier: Int, opacity: CGFloat = 0.25){
  
          //1. Create The SCNPlaneGeometry
          self.planeAnchor = anchor
          self.planeGeometry = SCNPlane(width: CGFloat(anchor.extent.x), height: CGFloat(anchor.extent.z))
          let planeNode = SCNNode(geometry: planeGeometry)
  
          super.init()
  
          //2. If The Image Bool Is True We Use The Default Image From The Assets Bundle
          let planeMaterial = SCNMaterial()
  
          if image{
  
              planeMaterial.diffuse.contents = UIImage(named: DEFAULT_IMAGE)
  
          }else{
  
              planeMaterial.diffuse.contents = UIColor.cyan
          }
  
          //3. Set The Geometries Contents
          self.planeGeometry.materials = [planeMaterial]
  
          //4. Set The Position Of The PlaneNode
          planeNode.simdPosition = float3(self.planeAnchor.center.x, 0, self.planeAnchor.center.z)
  
          //5. Rotate It On It's XAxis
          planeNode.eulerAngles.x = -.pi / 2
  
          //6. Set The Opacity Of The Node
          planeNode.opacity = opacity
  
          //7. Add The PlaneNode
          node.addChildNode(planeNode)
  
          //8. Set The Nodes ID
          node.name = "\(NAME) \(identifier)"
  
      }
  
      required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") }
  
      /// Updates The Size Of The Plane As & When The ARPlaneAnchor Has Been Updated
      ///
      /// - Parameter anchor: ARPlaneAnchor
      func update(_ anchor: ARPlaneAnchor) {
  
          self.planeAnchor = anchor
  
          self.planeGeometry.width = CGFloat(anchor.extent.x)
          self.planeGeometry.height = CGFloat(anchor.extent.z)
  
          self.position = SCNVector3Make(anchor.center.x, 0.01, anchor.center.z)
  
          returnPlaneInfo()
      }
  
      //-----------------------
      //MARK: Plane Information
      //-----------------------
  
      /// Returns The Size Of The ARPlaneAnchor & Its Alignment
      func returnPlaneInfo(){
  
          let widthOfPlane = self.planeAnchor.extent.x
          let heightOfPlane = self.planeAnchor.extent.z
  
          var planeAlignment: String!
  
          switch planeAnchor.alignment {
  
          case .horizontal:
              planeAlignment = "Horizontal"
          case .vertical:
              planeAlignment = "Vertical"
          }
  
          #if DEBUG
          print("""
              Width Of Plane =  \(String(format: "%.2fm", widthOfPlane))
              Height Of Plane =  \(String(format: "%.2fm", heightOfPlane))
              Plane Alignment = \(planeAlignment)
              """)
          #endif
  
          self.widthInfo = String(format: "%.2fm", widthOfPlane)
          self.heightInfo = String(format: "%.2fm", heightOfPlane)
          self.alignmentInfo = planeAlignment
        }
  
      }
  

  创建了子类之后，我们需要在ViewController中使用它。通常您会得到一个以上的ARPlaneAnchor，但是在此示例中，我们仅假设会有一个。

  因此，我们将创建一个引用 PlaneNode 的变量：

  var planeNode:PlaneNode?
  

  然后，在 ARSCNViewDelegate 中，我们将像这样创建 PlaneNode：

  func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
  
      //1. Get The Current ARPlaneAnchor
      guard let anchor = anchor as? ARPlaneAnchor else { return }
  
      //2. Create The PlaneNode
      if planeNode == nil{
          planeNode = PlaneNode(anchor: anchor, node: node, image: true, identifier: 0, opacity: 1)
          node.addChildNode(planeNode!)
          planeNode?.name = String("Detected Plane")
      }
  
  }
  

  然后，您所需要做的就是跟踪 PlaneNode e.g 的更新：

  func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) {
  
          guard let anchor = anchor as? ARPlaneAnchor, let existingPlane = planeNode else { return }
          existingPlane.update(anchor)
  }
  

  如果一切都按计划进行，您应该在consoleLog:中看到类似的内容

  平面宽度= 0.07m

  平面高度= 0.15m

  平面对齐=可选(“水平”)

  希望这足以让您入门...

  回复于 2024-04-29T04:23:51+08:00