【Unity】AssetBundle 资源打包和依赖资源打包

转载地址：http://blog.csdn.net/yxingyeyouyu/article/details/42921499

前段时间做了一个项目，刚好使用到了AssetBundle资源打包的东西，于是花了点时间研究了一下AssetBundle.

AssetBundle 打包

   我用NGUI插件加载了一张图片，并且把它拖拽为预制名为Texture3.prefab  和 Texture4.prefab .下面是我的打包函数

 [MenuItem("Assets/Build AssetBundle From Selection - Track dependencies")]
         static void ExportResource () {
             // 打开保存面板，获得选择的路径
             string path = EditorUtility.SaveFilePanel ("Save Resource", "", "New Resource", "unity3d");
             if (path.Length != 0) {
                 // 选择要保存的对象
                 Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
                 //开始打包
                 BuildPipeline.BuildAssetBundle(Selection.activeObject, selection, path, BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets,BuildTarget.StandaloneWindows);

                 //打包完成提示
                 EditorUtility.DisplayDialog("", "Build Completed", "OK");
                 //刷新资源目录
                 AssetDatabase.Refresh();
             }
         }

说明一下：  

1.我们打包的资源的后缀格式可以是 ".assetbundle" 或者 ".unity3d" 。笔者这里使用的是后者  

2. 解释一下打包函数的参数，第一个参数 Selection.activeObject 是我们打包的mainAsset ，

第二个参数 selection 是我们选择的对象过滤后的物体，可以为空，第三个参数 path 是 打包的资源的

保存路径 ，第四个参数是打包选项 ，我这里选用的两个选项 分别代表 打包所有有关联的对象和强制

打包全部的资源，详情请查找API文档 第五个参数是打包的平台。 

 

AssetBundle加载

下面是我写的加载函数：

 public string[] textureName;
     // Use this for initialization
     void Start () {
         for (int i = 0; i < textureName.Length; i++)
         {
             StartCoroutine(LoadAssetBundle(PlatflamPath() + textureName[i] + ".unity3d", textureName[i]));
         }
     }

     static public IEnumerator LoadAssetBundle(string filepath,string assetName) {
         WWW www = new WWW(filepath);
         yield return www;

         if (www == null) {
             Debug.Log(" www is null ");
         }
         else if (www.error != null) {
             Debug.Log("error " + www.error);
         }
         else if (www.isDone) {
             AssetBundle assetBundle = www.assetBundle;

             AssetBundleRequest requet = assetBundle.LoadAsync(assetName, typeof(GameObject));
             yield return requet;

             if (requet.isDone) {
                 GameObject obj = Instantiate(requet.asset) as GameObject;
             }
         }
         www.Dispose();
         www = null;
     }
     static public string PlatflamPath()
     {
         return string.Format("file://{0}", Application.streamingAssetsPath) + "/";
     }

AssetBundle依赖资源\共享资源打包

      上面的两个预制都是用了同一张图片，我们可以将这张图片打到没一个包里面去，我们上面将的就是这种情况。这样子做的话有些弊端，比如内存有点让费，并且当这张图片有所改变的时候，两个包需要重新打包。当然，我们也可以使用AssetBundle的依赖资源\共享资源进行打包。主要会使用到下面两个函数，
      BuildPipeline.PushAssetDependencies()：依赖资源压栈；


　　BuildPipeline.PopAssetDependencies()：依赖资源出栈。


      笔者将上表面的Texture3.prefab复制了两份，改为Texture1.prefab 和 Texture2.prefab。还准备好预制的图片

下面是我的打包函数:

 [MenuItem("Assets/Build Rely AssetBundle")]
         static public void ExportRelyAssetBundle() {
             string filePath = Application.streamingAssetsPath+"/";
             if (filePath.Length <= 0) {
                 return;
             }

             BuildAssetBundleOptions buildOp = BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets
             | BuildAssetBundleOptions.DeterministicAssetBundle;

             BuildPipeline.PushAssetDependencies();

                 Object shared = AssetDatabase.LoadMainAssetAtPath("Assets/Textures/rainDrop.png");
                 BuildPipeline.BuildAssetBundle(shared, null, filePath + shared.name + ".unity3d", buildOp, BuildTarget.StandaloneWindows);

                 BuildPipeline.PushAssetDependencies();
                     Object tex1 = AssetDatabase.LoadMainAssetAtPath("Assets/Textures/Texture1.prefab");
                     BuildPipeline.BuildAssetBundle(tex1, null, filePath + tex1.name + ".unity3d", buildOp, BuildTarget.StandaloneWindows);
                 BuildPipeline.PopAssetDependencies();

                 BuildPipeline.PushAssetDependencies();
                     Object tex2 = AssetDatabase.LoadMainAssetAtPath("Assets/Textures/Texture2.prefab");
                     BuildPipeline.BuildAssetBundle(tex2, null, filePath + tex2.name + ".unity3d", buildOp, BuildTarget.StandaloneWindows);
                 BuildPipeline.PopAssetDependencies();

             BuildPipeline.PopAssetDependencies();

             EditorUtility.DisplayDialog("", "Build Completed", "OK");
             AssetDatabase.Refresh();
         }

AssetBundle依赖资源\共享资源加载

 public string[] textureName;
     public string picName;
     // Use this for initialization
     void Start () {
         if (picName.Length > 0)
         {
             StartCoroutine(LoadAssetTexture(PlatflamPath() + picName + ".unity3d", picName));
         }

         for (int i = 0; i < textureName.Length; i++)
         {
             StartCoroutine(LoadAssetBundle(PlatflamPath() + textureName[i] + ".unity3d", textureName[i]));
         }
     }

     static public IEnumerator LoadAssetBundle(string filepath,string assetName) {
         WWW www = new WWW(filepath);
         yield return www;

         if (www == null) {
             Debug.Log(" www is null ");
         }
         else if (www.error != null) {
             Debug.Log("error " + www.error);
         }
         else if (www.isDone) {
             AssetBundle assetBundle = www.assetBundle;

             AssetBundleRequest requet = assetBundle.LoadAsync(assetName, typeof(GameObject));
             yield return requet;

             if (requet.isDone) {
                 GameObject obj = Instantiate(requet.asset) as GameObject;
             }
         }

         www.Dispose();
         www = null;
     }

     static public string PlatflamPath()
     {
         return string.Format("file://{0}", Application.streamingAssetsPath) + "/";
     }

     static public IEnumerator LoadAssetTexture(string filepath, string assetName)
     {
         WWW www = new WWW(filepath);
         yield return www;

         if (www == null)
         {
             Debug.Log(" www is null ");
         }
         else if (www.error != null)
         {
             Debug.Log("error " + www.error);
         }
         else if (www.isDone)
         {
             AssetBundle assetBundle = www.assetBundle;
         }

         www.Dispose();
         www = null;
     }

注意事项：

加载的时候需要加载图片，再加载跟它有关联的对象，笔者试过先加载后者，图片资源会丢失。
       另外，Push和Pos都是成对使用。

相比之下，后者打包的方式前者节省空间。具体使用情况还是视个人情况而定。