As all your Asset data must be pre-downloaded before your content starts, you should consider moving Assets out of your main data files and into AssetBundles. This way, you can create a small loader Scene for your content which loads quickly. It then dynamically loads Assets on-demand as the user proceeds through your content. AssetBundles also help with Asset data memory management: You can unload Asset data from memory for Assets that you don’t need any more by calling AssetBundle.Unload.
The following considerations apply when using AssetBundles on the WebGL platform:
When you use class types in your AssetBundle which are not used in your main build, Unity may strip the code for those classes from the build. This can cause a fail when trying to load Assets from the AssetBundle. Use BuildPlayerOptions.assetBundleManifestPath to fix that, or see the section on [Distribution size and code stripping](webgl-distribution size-codestripping.md), below, for other options.
WebGL 不支持线程，但 http 下载内容仅在下载完成后才可用。因此，在下载完成时，Unity WebGL 构建需要在主线程上解压缩 AssetBundle 数据，而这会阻止主线程。为避免这种中断，LZMA AssetBundle 压缩不可用于 WebGL 上的 AssetBundle。此情况下使用 LZ4 对 AssetBundle 进行压缩，这种压缩格式可非常高效地按需进行解压缩。如果所需的压缩大小比 LZ4 能够提供的压缩大小更小，可将 Web 服务器配置为对 AssetBundle 使用 gzip 或 Brotli 压缩（基于 LZ4 压缩）。请参阅有关部署压缩构建的文档以详细了解如何执行此操作。
WebGL supports AssetBundle caching with UnityWebRequestAssetBundle.GetAssetBundle. This method uses the IndexedDB API from your browser to store a cache on the user’s device. Some browsers might have limited support for IndexedDB and any browsers might request the user’s authorization to store data on the disk. For more information, see WebGL browser compatibility.