The document describes the evolution of a Unity project that spawns cars from prefabs over time. It starts by spawning directly from prefabs, then loads from Resources, then loads asynchronously from Resources. It then moves to building asset bundles and loading from them, both locally and remotely. Over time the code gets more robust, handling dependencies and loading asset bundles from a CDN. This reflects the ongoing process of improving systems and adapting to new needs and technologies.

9. 問題を解決するときはいつも、もっとも抵抗の少
ない道を選んで行けばたやすく解決しそうに見え
る。 しかして、その易しそうな道こそが最も過酷
で残酷なものに変質するのだ…
-Winston Churchill

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15. Unityプロジェクト 開発初週 - 直接参照
public class spawnCarFromDirectReference : MonoBehaviour
{
public GameObject carPrefab;
void Start ()
{
if(carPrefab != null)
GameObject.Instantiate(carPrefab, this.transform, false);
}
}

16. Unityプロジェクト,開発2週目 - Resources.Load
public class spawnCarFromResources : MonoBehaviour
{
public string carName;
void Start ()
{
var go = Resources.Load<GameObject>(carName);
if(go != null)
GameObject.Instantiate(go, this.transform, false);
}
}

17. Unityプロジェクト,開発3週目 - Resources.LoadAsync
public class spawnCarFromResourcesAsync : MonoBehaviour
{
public string carName;
IEnumerator Start ()
{
var req = Resources.LoadAsync(carName);
yield return req;
if(req.asset != null)
GameObject.Instantiate(req.asset, this.transform, false);
}
}

18. そして3ヶ月の時が流れた ...

19. Resourcesからアセットバンドルへの変更
public class MyBuildProcess
{
...
[MenuItem("Build/Build Asset Bundles")]
public static void BuildAssetBundles()
{
var outputPath = bundleBuildPath;
if(!Directory.Exists(outputPath))
Directory.CreateDirectory(outputPath);
var manifest = BuildPipeline.BuildAssetBundles(outputPath,
BuildAssetBundleOptions.ChunkBasedCompression,
EditorUserBuildSettings.activeBuildTarget);
var bundlesToCopy = new List<string>(manifest.GetAllAssetBundles());
// Copy the manifest file
bundlesToCopy.Add(EditorUserBuildSettings.activeBuildTarget.ToString());
CopyBundlesToStreamingAssets(bundlesToCopy);
}
...
}

20. Resourcesからアセットバンドルへの変更
public class spawnCarFromBuiltinAssetBundle : MonoBehaviour
{
public string carName;
public string carBundleName;
IEnumerator Start ()
{
if(!string.IsNullOrEmpty(carBundleName))
{
var bundleReq = AssetBundle.LoadFromFileAsync(carBundleName);
yield return bundleReq;
var bundle = bundleReq.assetBundle;
if( bundle != null)
{
var assetReq = bundle.LoadAssetAsync(carName);
yield return assetReq;
if(assetReq.asset != null)
GameObject.Instantiate(assetReq.asset, this.transform,
false);
}
}
}
}

21. そして3ヶ月後 ...

22. Asset BundlesをCDNからロードするよう書き換え
public class spawnCarFromRemoteAssetBundle : MonoBehaviour
{
public string carName;
public string carBundleName;
public string remoteUrl;
IEnumerator Start ()
{
var bundleUrl = Path.Combine(remoteUrl, carBundleName);
var webReq = UnityWebRequest.GetAssetBundle(bundleUrl);
var handler = webReq.downloadHandler as DownloadHandlerAssetBundle;
yield return webReq.Send();
var bundle = handler.assetBundle;
if(bundle != null)
{
var prefab = bundle.LoadAsset<GameObject>(carName);
if(prefab != null)
GameObject.Instantiate(prefab, this.transform, false);
}
}
}

23. Loading Asset Bundles from CDN
public class spawnCarFromRemoteAssetBundle : MonoBehaviour
{
public string carName;
public string carBundleName;
public string remoteUrl;
IEnumerator Start ()
{
var bundleUrl = Path.Combine(remoteUrl, carBundleName);
var webReq = UnityWebRequest.GetAssetBundle(bundleUrl);
var handler = webReq.downloadHandler as DownloadHandlerAssetBundle;
yield return webReq.Send();
var bundle = handler.assetBundle;
if(bundle != null)
{
var prefab = bundle.LoadAsset<GameObject>(carName);
if(prefab != null)
GameObject.Instantiate(prefab, this.transform, false);
}
}
}
こ
ん
な
コ
ー
ド
じ
ゃ
無
理
！
！

25. public class spawnCarFromRemoteAssetBundleWithDependencies : MonoBehaviour
{
// Simple class to handle loading asset bundles via UnityWebRequest
public class AssetBundleLoader
{
string uri;
string bundleName;
public AssetBundle assetBundle
{
get; private set;
}
public static AssetBundleLoader Factory(string uri, string bundleName)
{
return new AssetBundleLoader(uri, bundleName);
}
private AssetBundleLoader(string uri, string bundleName)
{
this.uri = uri;
this.bundleName = bundleName;
}
public IEnumerator Load()
{
var bundleUrl = Path.Combine(this.uri, this.bundleName);
var webReq = UnityWebRequest.GetAssetBundle(bundleUrl);
var handler = webReq.downloadHandler as
DownloadHandlerAssetBundle;
yield return webReq.Send();
assetBundle = handler.assetBundle;
}
}
public string carName;
public string carBundleName;
public string manifestName;
public string remoteUrl;
IEnumerator Start ()
{
var manifestLoader = AssetBundleLoader.Factory(remoteUrl,
bundleManifestName);
yield return manifestLoader.Load();
var manifestBundle = manifestLoader.assetBundle;
// Bail out if we can't load the manifest
if(manifestBundle == null)
{
Debug.LogWarning("Could not load asset bundle manifest.");
yield break;
}
var op =
manifestBundle.LoadAssetAsync<AssetBundleManifest>("AssetBundleManifest");
yield return op;
var manifest = op.asset as AssetBundleManifest;
var deps = manifest.GetAllDependencies(carBundleName);
foreach(var dep in deps)
{
Debug.LogFormat("Loading asset bundle dependency {0}", dep);
var loader = AssetBundleLoader.Factory(remoteUrl, dep);
yield return loader.Load();
}
var carLoader = AssetBundleLoader.Factory(remoteUrl, carBundleName);
yield return carLoader.Load();
if(carLoader.assetBundle != null)
{
op = carLoader.assetBundle.LoadAssetAsync<GameObject>(carName);
yield return op;
var prefab = op.asset as GameObject;
if(prefab != null)
GameObject.Instantiate(prefab, this.transform, false);
}
}
}

26. さらに求められる、アセットバンドルに必要な配慮:
• 一番効率的にアセットをバンドルに含める方法
• バンドル内のアセット重複回避
• バンドルに含まれているアセットの管理・確認
• バンドルのロードのメモリ管理

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33.
- heszkeWmeszke

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44. Unity 2017.1b (experimental)
https://github.com/Unity-Technologies/AssetBundles-BuildPipeline
UnityEditor.Experimental.Build.AssetBundle

45. Bundle Build Pipeline Overhaul Sneak Peak
public static AssetBundleBuildInput
GenerateAssetBundleBuildInput(
AssetBundleBuildSettings settings) { … }
public struct AssetBundleBuildInput
{
public struct Definition
{
public string name;
public string variant;
public GUID[] assets;
}
public AssetBundleBuildSettings settings;
public Definition[] bundles;
}
* Input generated from asset importer meta
data or any other source (external tools, etc.)

46. Bundle Build Pipeline Overhaul Sneak Peak
public static AssetBundleBuildCommandSet
GenerateAssetBuildCommandSet(
AssetBundleBuildInput buildInput) { … }
public struct AssetBundleBuildCommandSet
{
public struct Command
{
public AssetBundleBuildInput.Definition input;
public ObjectIdentifier[] objectsToBeWritten;
}
public AssetBundleBuildSettings settings;
public Command[] commands;
}
Command set generation gathers all
dependencies, handles object stripping, and
generates full list of objects to write.

47. Bundle Build Pipeline Overhaul Sneak Peak
public static void SaveAssetBundleOutput(AssetBundleBuildOutput output) { … }
Output can be serialized to JSON or any other
format as required.

48. Bundle Build Pipeline Overhaul Sneak Peak
public static void SaveAssetBundleOutput(AssetBundleBuildOutput output) { … }
Put it all together …
// Default build pipeline
SaveAssetBundleOutput(ExecuteAssetBuildCommandSet(GenerateAssetBuildComma
ndSet(GenerateAssetBundleBuildInput(settings))));

49. Unity 2017.1b

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55. public class spawnCarFromRemoteAssetBundleWithDependencies : MonoBehaviour
{
// Simple class to handle loading asset bundles via UnityWebRequest
public class AssetBundleLoader
{
string uri;
string bundleName;
public AssetBundle assetBundle
{
get; private set;
}
public static AssetBundleLoader Factory(string uri, string bundleName)
{
return new AssetBundleLoader(uri, bundleName);
}
private AssetBundleLoader(string uri, string bundleName)
{
this.uri = uri;
this.bundleName = bundleName;
}
public IEnumerator Load()
{
var bundleUrl = Path.Combine(this.uri, this.bundleName);
var webReq = UnityWebRequest.GetAssetBundle(bundleUrl);
var handler = webReq.downloadHandler as
DownloadHandlerAssetBundle;
yield return webReq.Send();
assetBundle = handler.assetBundle;
}
}
public string carName;
public string carBundleName;
public string manifestName;
public string remoteUrl;
IEnumerator Start ()
{
var manifestLoader = AssetBundleLoader.Factory(remoteUrl,
bundleManifestName);
yield return manifestLoader.Load();
var manifestBundle = manifestLoader.assetBundle;
// Bail out if we can't load the manifest
if(manifestBundle == null)
{
Debug.LogWarning("Could not load asset bundle manifest.");
yield break;
}
var op =
manifestBundle.LoadAssetAsync<AssetBundleManifest>("AssetBundleManifest");
yield return op;
var manifest = op.asset as AssetBundleManifest;
var deps = manifest.GetAllDependencies(carBundleName);
foreach(var dep in deps)
{
Debug.LogFormat("Loading asset bundle dependency {0}", dep);
var loader = AssetBundleLoader.Factory(remoteUrl, dep);
yield return loader.Load();
}
var carLoader = AssetBundleLoader.Factory(remoteUrl, carBundleName);
yield return carLoader.Load();
if(carLoader.assetBundle != null)
{
op = carLoader.assetBundle.LoadAssetAsync<GameObject>(carName);
yield return op;
var prefab = op.asset as GameObject;
if(prefab != null)
GameObject.Instantiate(prefab, this.transform, false);
}
}
}

56. public class spawnCarFromRemoteAssetBundleWithDependencies : MonoBehaviour
{
// Simple class to handle loading asset bundles via UnityWebRequest
public class AssetBundleLoader
{
string uri;
string bundleName;
public AssetBundle assetBundle
{
get; private set;
}
public static AssetBundleLoader Factory(string uri, string bundleName)
{
return new AssetBundleLoader(uri, bundleName);
}
private AssetBundleLoader(string uri, string bundleName)
{
this.uri = uri;
this.bundleName = bundleName;
}
public IEnumerator Load()
{
var bundleUrl = Path.Combine(this.uri, this.bundleName);
var webReq = UnityWebRequest.GetAssetBundle(bundleUrl);
var handler = webReq.downloadHandler as
DownloadHandlerAssetBundle;
yield return webReq.Send();
assetBundle = handler.assetBundle;
}
}
public string carName;
public string carBundleName;
public string manifestName;
public string remoteUrl;
IEnumerator Start ()
{
var manifestLoader = AssetBundleLoader.Factory(remoteUrl,
bundleManifestName);
yield return manifestLoader.Load();
var manifestBundle = manifestLoader.assetBundle;
// Bail out if we can't load the manifest
if(manifestBundle == null)
{
Debug.LogWarning("Could not load asset bundle manifest.");
yield break;
}
var op =
manifestBundle.LoadAssetAsync<AssetBundleManifest>("AssetBundleManifest");
yield return op;
var manifest = op.asset as AssetBundleManifest;
var deps = manifest.GetAllDependencies(carBundleName);
foreach(var dep in deps)
{
Debug.LogFormat("Loading asset bundle dependency {0}", dep);
var loader = AssetBundleLoader.Factory(remoteUrl, dep);
yield return loader.Load();
}
var carLoader = AssetBundleLoader.Factory(remoteUrl, carBundleName);
yield return carLoader.Load();
if(carLoader.assetBundle != null)
{
op = carLoader.assetBundle.LoadAssetAsync<GameObject>(carName);
yield return op;
var prefab = op.asset as GameObject;
if(prefab != null)
GameObject.Instantiate(prefab, this.transform, false);
}
}
}

57. public class spawnCarFromResourcesAsync : MonoBehaviour
{
public string carName;
IEnumerator Start ()
{
var req = Resources.LoadAsync(carName);
yield return req;
if(req.asset != null)
GameObject.Instantiate(req.asset, this.transform, false);
}
}

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62. ✓
✓
✓
✓

66. ★
★