如何使用 ARKit 从远程服务器加载 usdz 模型和纹理？答案

【问题标题】：How to load a usdz model and textures from a remote server using ARKit?如何使用 ARKit 从远程服务器加载 usdz 模型和纹理？
【发布时间】：2021-02-07 15:12:17
【问题描述】：

如何使用 ARKit 从远程服务器加载usdz 模型和纹理？

如下例：

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!)

【问题讨论】：

您是否尝试过在 SCNScene 初始化时捕获错误？它可能会让你知道出了什么问题

标签： swift augmented-reality arkit usdz

【解决方案1】：

我找到了如下解决方案：

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)")
    }
  }
}

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!)

}

【讨论】：