c# - 运行时从外部服务器下载 AssetBundle 时出错

Question

我正在尝试在运行时从外部服务器下载带有 AssetBundle 的 3d 模型。我创建了一个assetBundle，然后将 AssetBundle 文件上传到外部服务器。

下面是代码：

// Use this for initialization
void Start() {
    StartCoroutine("DownloadObject");
}

IEnumerator DownloadObject() {
    WWW www = WWW.LoadFromCacheOrDownload("http://infinitodesign.net/amir/dog", 1); //Download from server
    yield return www;


    if(www != null) {
        Debug.Log("wwww is empty");
    }
    AssetBundle bundle = www.assetBundle;//Get the AssetBundle

    AssetBundleRequest request = bundle.LoadAssetAsync<GameObject>("dog");
    yield return request;

    GameObject dog = request.asset as GameObject;
    Instantiate<GameObject>(dog);
}

当我在 Unity 中运行时，我发现 www 是空的