Is it possible to load images recovered from a server in runtime into a plane object? - swift

Question

I have been asked to build an app that shows a catalog with AR, so what I need to do is pretty simple: when an user chooses a product I must load the image recovered in base64 from the server into a plane object. Is this possible with swift - arkit ? Or are all the sprites/images/textures required to be previously loaded into the assets folder?

Answer 1

You can definitely download resources from a server, save them to the device (e.g in NSDocumentsDirectory), and then load with the file URL. I do it for a similar use case as yours -at least it sounds so, per the description you gave-
EDIT
Here's the relevant code. I use Alamofire to download from the server and ZIPFoundation for unzipping. I believe that if you just need to download an image, it'll be a bit simpler, probably not needing the unzip part.
let modelsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
func loadNodeWithID(_ id: String, completion: #escaping (SCNNode?) -> Void) {
// Check that assets for that model are not already downloaded
let fileManager = FileManager.default
let dirForModel = modelsDirectory.appendingPathComponent(id)
let dirExists = fileManager.fileExists(atPath: dirForModel.path)
if dirExists {
completion(loadNodeWithIdFromDisk(id))
} else {
let dumbURL = "http://yourserver/yourfile.zip"
downloadZip(from: dumbURL, at: id) {
if let url = $0 {
print("Downloaded and unzipped at: \(url.absoluteString)")
completion(self.loadNodeWithIdFromDisk(id))
} else {
print("Something went wrong!")
completion(nil)
}
}
}
}
func loadNodeWithIdFromDisk(_ id: String) -> SCNNode? {
let fileManager = FileManager.default
let dirForModel = modelsDirectory.appendingPathComponent(id)
do {
let files = try fileManager.contentsOfDirectory(atPath: dirForModel.path)
if let objFile = files.first(where: { $0.hasSuffix(".obj") }) {
let objScene = try? SCNScene(url: dirForModel.appendingPathComponent(objFile), options: nil)
let objNode = objScene?.rootNode.firstChild()
return objNode
} else {
print("No obj file in directory: \(dirForModel.path)")
return nil
}
} catch {
print("Could not enumarate files or load scene: \(error)")
return nil
}
}
func downloadZip(from urlString: String, at destFileName: String, completion: ((URL?) -> Void)?) {
print("Downloading \(urlString)")
let fullDestName = destFileName + ".zip"
let destination: DownloadRequest.DownloadFileDestination = { _, _ in
let fileURL = modelsDirectory.appendingPathComponent(fullDestName)
return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
}
Alamofire.download(urlString, to: destination).response { response in
let error = response.error
if error == nil {
if let filePath = response.destinationURL?.path {
let nStr = NSString(string: filePath)
let id = NSString(string: nStr.lastPathComponent).deletingPathExtension
print(response)
print("file downloaded at: \(filePath)")
let fileManager = FileManager()
let sourceURL = URL(fileURLWithPath: filePath)
var destinationURL = modelsDirectory
destinationURL.appendPathComponent(id)
do {
try fileManager.createDirectory(at: destinationURL, withIntermediateDirectories: true, attributes: nil)
try fileManager.unzipItem(at: sourceURL, to: destinationURL)
completion?(destinationURL)
} catch {
completion?(nil)
print("Extraction of ZIP archive failed with error: \(error)")
}
} else {
completion?(nil)
print("File path not found")
}
} else {
// Handle error
completion?(nil)
}
}
}