unity3D制作并使用Assetbundles方法

在网页中为了控制.unity文件的大小，加速载入速度，可以把系统用到的资源制作成Assestbundles，根据需要进行动态的加载和卸载。具体作法：

1、使用脚本重新定义系统菜单，添加一个制作Assetbunles的菜单命令：

// C# Example

// Builds an asset bundle from the selected objects in the project view.

// Once compiled go to "Menu" -> "Assets" and select one of the choices

// to build the Asset Bundle

 

using UnityEngine;

using UnityEditor;

 

public class ExportAssetBundles {

[MenuItem("Assets/Build AssetBundle From Selection - Track dependencies")]

static void ExportResource () {

// Bring up save panel

string path = EditorUtility.SaveFilePanel ("Save Resource", "", "New Resource", "unity3d");

if (path.Length != 0) {

// Build the resource file from the active selection.

Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);

BuildPipeline.BuildAssetBundle(Selection.activeObject, selection, path, BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets);

Selection.objects = selection;

}

}

[MenuItem("Assets/Build AssetBundle From Selection - No dependency tracking")]

static void ExportResourceNoTrack () {

// Bring up save panel

string path = EditorUtility.SaveFilePanel ("Save Resource", "", "New Resource", "unity3d");

if (path.Length != 0) {

// Build the resource file from the active selection.

BuildPipeline.BuildAssetBundle(Selection.activeObject, Selection.objects, path);

}

}

}

以上脚本按类命名后放置在工程文件夹内Assets目录内的Edit文件夹内（如没有，自行新建）。这时如脚本描述的在菜单栏内的Assets下会出现Build AssetBundle From Selection的两个菜单，选中需要制作Assetbunles的资源生成即可。

2、使用www按需载入Assetbundle，举例如下

function Start () {

var url = "file:///D:/temp/XXX.unity3d";

StartCoroutine(LoadAsset(url));

}

function LoadAsset (url : String) {

var www : WWW = new WWW (url);

yield www;

var present : GameObject;

present = GameObject.Find("present");

if( present != null )

Destroy(present);

present = Instantiate(www.assetBundle.mainAsset);

present.name = "present"; //暂时把名字叫做“present”

}