我正在使用ARKit开发我的应用程序,并尝试从我的Web服务器(URL)动态加载.scn文件。
以下是我的代码的一部分:
let urlString = "https://da5645f1.ngrok.io/mug.scn"
let url = URL.init(string: urlString)
let request = URLRequest(url: url!)
let session = URLSession.shared
let downloadTask = session.downloadTask(with: request,
completionHandler: { (location:URL?, response:URLResponse?, error:Error?)
-> Void in
print("location:\(String(describing: location))")
let locationPath = location!.path
let documents:String = NSHomeDirectory() + "/Documents/mug.scn"
ls = NSHomeDirectory() + "/Documents"
let fileManager = FileManager.default
if (fileManager.fileExists(atPath: documents)){
try! fileManager.removeItem(atPath: documents)
}
try! fileManager.moveItem(atPath: locationPath, toPath: documents)
print("new location:\(documents)")
let node = SCNNode()
let scene = SCNScene(named:"mug.scn", inDirectory: ls)
let nodess = scene?.rootNode.childNode(withName: "Mug", recursively: true)
node.addChildNode(nodess!)
let nodeArray = scene!.rootNode.childNodes
for childNode in nodeArray {
node.addChildNode(childNode as SCNNode)
}
self.addChildNode(node)
self.modelLoaded = true
})
downloadTask.resume()
Nslog:
location:Optional(file:///private/var/mobile/Containers/Data/Application/A1B996D7-ABE9-4000-91DB-2370076198D5/tmp/CFNetworkDownload_duDlwf.tmp)
new location:/var/mobile/Containers/Data/Application/A1B996D7-ABE9-4000-91DB-2370076198D5/Documents/mug.scn
使用上述(新位置)文件路径下载.scn文件。但当我尝试在SCNScene
中使用此下载的文件时,出现问题。
let scene = SCNScene(named:"mug.scn", inDirectory: ls)
场景值始终为 nil
。错误信息如下:
Thread 4: Fatal error: Unexpectedly found nil while unwrapping an Optional value
如何解决此问题。谢谢。
SCNMaterial
吗?或者你需要为你的场景设置overrideAssetURLs
吗? - mugx