WebP format texture

UniVGO experimental features manual

Manual for experimental features.

WebP format texture

1-1. Unity Editor

Unity 2021.2 or higher.

1-2. Package

<Project>/Packages/package.json.

{
  "scopedRegistries": [
    {
      "name": "Unity NuGet",
      "url": "https://unitynuget-registry.azurewebsites.net",
      "scopes": ["org.nuget"]
    }
  ],
  "dependencies": {
    "org.nuget.sixlabors.imagesharp": "2.1.5",
  }
}

1-3. Define symbol

Unity Editor

Menu Bar > Edit > Projcet Settings

Projcet Settings Window

Player > Other Settings > Script Compilation > Scripting Define Symbols

Add the Define symbol.

UNIVGO_EXPORT_WEBP_TEXTURE_ENABLE

1-4. Export

Select the GameObject you want to output in Hierarchy.

Click the Export VGO button of Vgo Generator in Inspector.

Set the export condition.

Select the WebP (expt) radio button for Texture Type.

Finally, click the Export button.

1-5. Import / Load

There is no difference in the operating procedure from the normal case.

1-6. Comparison

Comparison data of PNG and WebP.

The target is a humanoid avatar with 6 textures.

Subject	PNG	WebP	Ratio
File Size	20MB	17.5MB	-13%
Export Time	2,500ms	81,000ms	+3240%
Import Time	1,500ms	10,200ms	+680%
Runtime Load Time (Editor, sync)	1,500ms	14,000ms	+933%
Runtime Load Time (Editor, async)	2,200ms	5,700ms	+250%
Runtime Load Time (IL2CPP, async)	1,100ms	2,500ms	+227%

1-7. Inspection result

The data size of the VGO file is reduced by high compressing the image data.

On the other hand, the image data encoding / decoding process becomes heavy.

Also, since Unity Engine does not support WebP format, it is necessary to go through format conversion processing.

Due to the specifications of the Unity Editor, export processing cannot be performed asynchronously or in parallel, so export processing takes time.

Synchronous processing may be faster than asynchronous processing because, according to Unity Engine specifications, important processing must be performed on the main thread, and there are almost no cases where parallelization is possible.

Downloading a VGO file using UnityWebRequest.Get(uri) is faster, but VgoImporter.LoadAsync() is slower.