Unity Auto Bundles by perholmes - 1


Extension to Unity's Addressables for making it easier to distribute large projects and keep mobile download size small.

Unknown VersionMIT LicenseUpdated 1 year agoCreated on September 11th, 2020
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Unity AutoBundles

Extension to Unity Engine’s Addressables for making it easier to distribute large projects and keep mobile download size small.

  • Just create a folder for all your assets.
  • Automatically generate Addressables and keep them synced.
  • Creates one .bundle file for each asset, resulting in your app only downloading or updating EXACTLY what it needs, reducing caching, bandwidth and storage dramatically.
  • Heavy dependency checking. Only bundles things that are referenced, and splits out assets that are used by multiple assets.
  • Creates the smallest number of bundles necessary to download only what’s needed for each scene.
  • Allows you to force some assets to become addressable, even if they’re unreferenced.
  • The goal is extreme automation. No babysitting. Just a giant bucket of assets, and the script does the right thing.

How does it work?

You just arrange all your assets in a folder called AutoBundles:


Addressables are automatically created for everything in this folder, each single item as its own Addressable.



  • Organize your assets in folders under AutoBundles.
  • Each top-level folder becomes an Addressable group.
  • You only organize the AutoBundles folder. Addressables are magically created, optimized and synced.
  • Each asset become an addressable unless:
    • It’s not the right type or file extension.
    • It has zero or one parents.
    • It has zero or one ultimate parents (ensuring that we don’t create multiple bundles for what is ultimately just pieces of one asset).
    • It’s not part of any scene.
    • It’s too small to warrant its own bundle file. Gets duplicated into multiple bundles instead, to reduce number of bundles.
  • Any assets not bundled are still included by the Addressables framework if needed, just not in a separate bundle file.
  • You can force the inclusion of an asset by adding the label “ForceAddressable”, e.g. if you intend to address the asset manually, and it’s currently unreferenced.
  • You only push actual changes to the CDN.
  • User only downloads what’s needed for the scenes/assets they’re intending to run.


  • Multi-file bundles are bad for users, because they result in extreme over-caching especially on mobile.
  • By making every texture, prefab, material, or whatever, its own Addressable, downloading and updating is as nimble as possible.
  • Manually labelling Addressables is a drag, especially if you have 10,000 assets.
  • Manually optimizing Addressables is a drag. AutoBundles creates the lowest number of bundles that still give you individual download access to the assets you care about.
  • You already have a folder structure. Why not just lean on that?
  • AutoBundles is two-click automation. Hopefully zero-click in the future.

How To Use It:

Simply open the AutoBundles Analyze Rule:


Then press Fix Selected Rules, and the Addressables are updated to mirror the AutoBundles folder structure. Only groups starting with “(Auto)” are synced, and tagging of individual assets is preserved.


  • It uses more file handles to open more bundles at runtime. But this is drastically reduced in latest version.
  • It’s more web requests. But with concurrent requests set to just 32, you don’t feel any slowdown.

How To Install

  • Copy Editor/AutoBundles.cs into your project.
  • Copy Scripts/… if you want the testing scripts.
  • Create a folder in Assets called AutoBundles.
  • Make sure that your “Packed Assets” settings (Assets/AddressableAssetsData/AssetGroupTemplates/Packed Assets) has the following settings:
    • Bundle Mode: Pack Separately
    • Bundle Naming: Use Hash Of AssetBundle
  • Make sure your Addressable settings are 32 concurrent downloads.
  • The Hash-based naming (e.g. "3c3b1761ce87715d3177d2c5ec7d27ac.bundle ") is to frustrate reverse-engineering by making all assets incomprehensible. In the future, encryption should also be added.


If others find this useful, maybe we can work together on designing the script better.


Per Holmes

Hollywood Camera Work


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