Download AssetBundle in hard disk

This is not really complicated. Handle it like a normal file you would download from the internet but save it with the “.unity3d” extension.

1.Download the AssetBundle as a normal file by making a request with UnityWebRequest.

UnityWebRequest www = UnityWebRequest.Get(url);
yield return www.Send();

2.Retrieve the byte array data with DownloadHandler.data then save it to Application.persistentDataPath/yourfolder/filename.unity3d. Make sure that the extension is “.unity3d”.

File.WriteAllBytes(handle.data, data);

That’s it.

3.To load the data, use AssetBundle.LoadFromFile or AssetBundle.LoadFromFileAsync:

AssetBundleCreateRequest bundle = AssetBundle.LoadFromFileAsync(path);

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If still confused, here is what the thing should look like. You may need to make some modification:

Download and Save:

IEnumerator downloadAsset()
{
    string url = "http://url.net/YourAsset.unity3d";

    UnityWebRequest www = UnityWebRequest.Get(url);
    DownloadHandler handle = www.downloadHandler;

    //Send Request and wait
    yield return www.Send();

    if (www.isError)
    {

        UnityEngine.Debug.Log("Error while Downloading Data: " + www.error);
    }
    else
    {
        UnityEngine.Debug.Log("Success");

        //handle.data

        //Construct path to save it
        string dataFileName = "WaterVehicles";
        string tempPath = Path.Combine(Application.persistentDataPath, "AssetData");
        tempPath = Path.Combine(tempPath, dataFileName + ".unity3d");

        //Save
        save(handle.data, tempPath);
    }
}

void save(byte[] data, string path)
{
    //Create the Directory if it does not exist
    if (!Directory.Exists(Path.GetDirectoryName(path)))
    {
        Directory.CreateDirectory(Path.GetDirectoryName(path));
    }

    try
    {
        File.WriteAllBytes(path, data);
        Debug.Log("Saved Data to: " + path.Replace("https://stackoverflow.com/", "\\"));
    }
    catch (Exception e)
    {
        Debug.LogWarning("Failed To Save Data to: " + path.Replace("https://stackoverflow.com/", "\\"));
        Debug.LogWarning("Error: " + e.Message);
    }
}

Load:

IEnumerable LoadObject(string path)
{
    AssetBundleCreateRequest bundle = AssetBundle.LoadFromFileAsync(path);
    yield return bundle;

    AssetBundle myLoadedAssetBundle = bundle.assetBundle;
    if (myLoadedAssetBundle == null)
    {
        Debug.Log("Failed to load AssetBundle!");
        yield break;
    }

    AssetBundleRequest request = myLoadedAssetBundle.LoadAssetAsync<GameObject>("boat");
    yield return request;

    GameObject obj = request.asset as GameObject;
    obj.transform.position = new Vector3(0.08f, -2.345f, 297.54f);
    obj.transform.Rotate(350.41f, 400f, 20f);
    obj.transform.localScale = new Vector3(1.0518f, 0.998f, 1.1793f);

    Instantiate(obj);

    myLoadedAssetBundle.Unload(false);
}