What compression should we be using for WebGL Asset Bundles?

So I was reading the 5.5 beta change log and I found an interesting tidbit:

Uh what? This is certainly news to me. I've always been under the impression that for downloads (WWW/UnityWebRequest) you want to use lzma (for smaller files) and only use lz4 if you are loading the bundles locally (LoadFromFile).

I'm guessing you want us to use chunk compression (lz4)? Where was this previously "discouraged"? Can you add this information to https://docs.unity3d.com/Manual/AssetBundleCompression.html? The "best practices" for asset bundles are not clear for WebGL.

 

Believe it or not, Unity best practices for WebGL suggests using UNCOMPRESSED assetbundles now.

See section 4.8 here:

https://unity3d.com/es/learn/tutorials/topics/best-practices/assetbundle-usage-patterns

 

Ah that's what they were referencing? But why take this option away if it's just the performance loading issue we've always had? Just make it crystal clear in the documentation the ramifications of compressed bundles. I was worried they were referencing some runtime cost that I was unaware of.

So sadly this negatively impacts us. We split our applications into like 50 asset bundles and load them behind a javascript/html loader (i.e. we hide the unity webgl content while it's loading the application/bundles). Thus this "feature" does nothing for us other than increase our sever and transportation costs.

I don't get the logic behind removing a perfectly functioning feature in order to combat ignorance...

 

We deal with many (hundreds, potentially thousands) of assetbundles per game session so it impacts us as well.

Our pipeline is such, however, that we can pretty easily redeploy uncompressed assetbundles. BUT, Unity mentions that gzip compression makes sense for WebGL-targeted assetbundles. Why not simply include gzip as a compression option when building assetbundles then? And I agree, even if LZMA is inefficient, if it's not flat-out broken why break a great deal of compatibility with existing projects?

We've tested some manual gzip compression (our CDN host doesnt offer gzip compression automatically) without any luck so far. Still looking into it.

 

Jonas,

Does this mean that the 'best practices' documentation for Assetbundles referenced above is out-of-date (due to 5.5) or simply incorrect in terms of compression suggestions?

 

Thanks @jonas-echterhoff for the explanation. I can live with LZ4 compression. And thanks for trying to update the documentation, it wasn't very clear what the optimal settings were for webgl.

 

Does the slowness of LZMA de-compression under webgl out-weigh the much bigger download size of the assetbundles with LZ4 compression then?
Also can anyone give a brief explanation of how you serve them with gzip compression?

 

https://forum.unity.com/threads/web...asset-bundle-through-www.389447/#post-3297378

 

Sorry for bumping back this thread but I am having similar problems and would like some advise...

We deploy on both Standalone and Webgl and the difference is literally the double of the size for WebGL.

Our users are bandwidth dependent and we can't force server-side compression such as gzip. Lastly, our building is highly automated with custom scripts, so we don't use the default publishing menu at all, limiting us with the post-build compression of Unity (such as gzip if ever we find a way to use it).

Any suggestions?

 

It's 77% bigger; one exemple standalone bundle is ~40mb, vs the WebGL version is ~71mb. We have multiple assetbundles.

Bundle compression is LZ4 (BuildAssetBundleOptions.ChunkBasedCompression) as per documentation.

Something we noticed, I don't know if it's particular or not, is that according to the Editor Log;

(Standalone):

Compressed Size:40.2 mb

Uncompressed usage by category:

Textures      71.2 mb    45.2%

Meshes        24.6 mb    15.6%

Animations    2.1 kb    0.0%

Sounds        0.0 kb    0.0%

Shaders       1.2 mb    0.8%

Other Assets  327.1 kb    0.2%

Levels        59.9 mb    38.1%

Scripts       2.2 kb    0.0%

Included DLLs 0.0 kb    0.0%

File headers  98.5 kb    0.1%

Complete size 157.3 mb    100.0%

(WebgL):

Compressed Size:71.1 mb

Uncompressed usage by category:

Textures      71.2 mb    41.2%

Meshes        24.6 mb    14.3%

Animations    2.1 kb    0.0%

Sounds        0.0 kb    0.0%

Shaders       2.1 mb    1.2%

Other Assets  327.1 kb    0.2%

Levels        74.2 mb    43.0%

Scripts       2.2 kb    0.0%

Included DLLs 0.0 kb    0.0%

File headers  98.5 kb    0.1%

Complete size 172.5 mb    100.0%

Notice the "Levels", it's 15mb bigger. It accounts for the biggest delta between both export options.

 

We deploy our web-based version of our product on our clients LMSs, for which we do not control the server configuration. Additionally, as our products are not games, the production environments are more tightly controlled (security, stable configs, etc). Wasn't a problem with the old web player and when our projects were smaller but now we are having trouble delivering our mandates without re-scoping down even more for WebGL. It really hampers our development efforts.

Is there any way to get LZMA back for WebGL, or any other alternatives?

 

You don't want LZMA...you want Unity to give us the ability to compress (WebGL) bundles with gzip or brotli so the browser can handle decompression.

 

I am using LZ4 Compression, but seems it not working fine. https://forum.unity.com/threads/ope...et-bundle-in-unity-webgl.656563/#post-4397368

 

Amusingly we just switched off LZ4 last week as we finally migrated all of our webgl bundles to be uncompressed + gzip! Makes a huge difference on slow (Android...) devices. However prior to that we had no issues with LZ4. Here's our old build options (nothing too crazy):

Code (CSharp):

1. BuildAssetBundleOptions options = (BuildAssetBundleOptions.ChunkBasedCompression | BuildAssetBundleOptions.DisableLoadAssetByFileName | BuildAssetBundleOptions.DisableLoadAssetByFileNameWithExtension);

 

Can anyone tell me how to compress my asset bundle with gzip? Currently, i am using asset bundle browser and there are three compression types in it:
1 No Compression,
2. LZ4 (LZ4 is right choice for webgl)?
3. LZMA (LZMA is obselete according to this thread?)

I am using Unity 2019 with Webgl build. Thanks

 

The idea is that you enable gzip compression on your web host, typically using Nginx or Apache, alternatively you gzip it yourself and configure them to use the gzip'd version if a request comes in that can accept it.