如何访问从 Firebase 下载的 SceneKit 文件？

Question

• I have an ARKit app that uses image recognition to trigger SceneKit/3D Object files, specifically for art exhibitions. I've recently began implementing Firebase Storage in order to reduce the overall download size and rather download the 3D files on demand, per which exhibition the user is using!

I've successfully set up the app to download the SceneKit files to the mobile storage, but where I am stuck now is figuring out how to read the file from the specific downloaded location and continue working it in the image recognition/AR process accordingly.

Before, when the Scenekit files were included in the initial download via Scenekit Catalog in the app folder, I would read them like so:

   let ShipScene = SCNScene(named: "art.scnassets/ship.scn")

Now, I've updated it to read the same string as the download URL, but the image recognition is not working.

I assume my problem is that it is not reading the right location, or I may be using the wrong function. I've put the app through to my phone through TestFlight and still no luck.

// Downloading from firebase to device URL

  let shipURL = documentsURL.appendingPathComponent("file:///var/mobile/Containers/Data/Application/QZ_Gallery/SceneKitFiles/ship.scn", isDirectory: true)


 let shipDownload = shipRef.write(toFile: shipURL)

 // Attempting to pull the file from the downloaded location

 let ShipScene = SCNScene(named:"file:///var/mobile/Containers/Data/Application/QZ_Gallery/SceneKitFiles/ship.scn" )

*** My question is in the final line of code I included. I am trying to make sure I am searching in the right place to retrieve the files that were downloaded, or if the function I am using is even proper for retrieving files stored locally on a mobile device.

Answer 1

Solved by first adding a function to find the scenepath of the container which has all my scenes, and then using the scene path in the fetching of the individual.scn file. Scene downloads from Firebase Storage (No use of Realtime Database) and integrates properly with the image recognition.

      let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

                  let scenePath = documentsURL.appendingPathComponent("Scenes")
                  if(!FileManager.default.fileExists(atPath: scenePath.absoluteString)) {
                      do {
                          try FileManager.default.createDirectory(atPath: scenePath.absoluteString, withIntermediateDirectories: true, attributes: nil)
                          } catch {
                              print(error.localizedDescription);
                          }
                  }

           // Start Download, writing to a file




        let sceneURL = scenePath.appendingPathComponent("Ship.scn", isDirectory: true)