swift - 如何使用 ARKit 从远程服务器加载 usdz 模型和纹理？

Question

如何使用 ARKit 从远程服务器加载 usdz 模型和纹理？

如下例所示:

let myURL = NSURL(string: "https://mywebsite.com/vase.scn")

guard let scene = try? SCNScene(url: myURL! as URL, options: nil) else {
    return
}

let node = scene.rootNode.childNode(withName: "vase", recursively: true)

let transform = queryResult.worldTransform
let thirdColumn = transform.columns.3
node!.position = SCNVector3(thirdColumn.x, thirdColumn.y, thirdColumn.z)
self.sceneView.scene.rootNode.addChildNode(node!)

Answer 1

我找到了如下解决方案:

1. 下载模型并保存

   func downloadModel() {
   
       guard let url = URL(url: originalURL) else { return }
       let urlSession = URLSession(configuration: .default, delegate: self, delegateQueue: OperationQueue())
       let downloadTask = urlSession.downloadTask(with: url)
       downloadTask.resume()
   }
   
   extension ARViewController: URLSessionDownloadDelegate {
   
        public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {          print("locationUrl:", location.path)
   
         // create destination URL with the original file name
            guard let url = downloadTask.originalRequest?.url else { return }
            let documentsPath = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)[0]
           let destinationURL = documentsPath.appendingPathComponent(url.lastPathComponent)
   
         // delete original copy
            try? FileManager.default.removeItem(at: destinationURL)
   
         // copy from temp to Document
     do {
           try FileManager.default.copyItem(at: location, to: destinationURL)
           self.originalURL = destinationURL
           print("originalURL:", originalURL!.path)
   
      } catch let error {
       print("Copy Error: \(error.localizedDescription)")
       }
     }
   }
   

2. 加载 usdz 模型和纹理

   func addItem(queryResult: ARRaycastResult) {
   
       let url = URL(string: originalURL!.path)
       let mdlAsset = MDLAsset(url: url!)
       mdlAsset.loadTextures()
       let scene = SCNScene(mdlAsset: mdlAsset)
       let node = scene.rootNode.childNode(withName: "model", recursively: true)
       let transform = queryResult.worldTransform
       let thirdColumn = transform.columns.3
       node!.position = SCNVector3(thirdColumn.x, thirdColumn.y, thirdColumn.z)
       self.sceneView.scene.rootNode.addChildNode(node!)
   
   }