Android 2D Textures Overrides

This page details the Texture Overrides specific to Android. A description of the general Texture Overrides can be found here.

The information contained on this page assumes the reader has working knowledge of DXT and ETC Texture compression, OpenGL ES and Android development.

Further information about Texture compression and OpenGL ES can be found on the following Wikipedia pages:

• DXT Texture compression
• ETC(Ericsson Texture Compression
• Lossy compression
• OpenGL ES

If a your app is installed on a device that does not support the Texture compression format you have used, Unity will decompress the Textures to RGBA 32 and store them in the device’s memory—along with the compressed Textures—when the app is running. This will lead to increased loading times and higher memory usage as Unity must decompress the Textures and store two versions of the Textures used (compressed and uncompressed).This can also have a large impact on rendering performance, especially on older, slower devices.

Use ETC2 compression unless you are targeting specific hardware (like Nvidia Tegra). ETC2 supports Textures with and without an alpha channel and is supported by all OpenGL ES 3 devices. To avoid software decompression, set the minimum graphics API to OpenGL ES 3 in the Android Player settings by removing OpenGL ES 2 from the Graphics APIs list and setting the Minimum API Level to 18+.

To target OpenGL ES 2 and OpenGL ES 3 devices, you can create two different APKs by first building an APK targeting OpenGL ES 3, as shown above, and then building an APK targeting OpenGL ES 2 by removing OpenGL ES 2 and Vulcan from the Graphics APIs section of the Player settings. You can then publish both of these APKs to the Google Play Store. When a user downloads your app, the Google Play Store will automatically install the most relevant APK for their device. For more information about publishing multiple APK files, see Android Developer documentation on Publishing Multiple APKs and Google Play Store APK filtering.

When building an APK that targets OpenGL ES 2, you can use ETC1 texture compression.

The Texture compression format for OpenGL ES2-targeted APK can be ETC1. Unity can use ETC1 for Textures with Alpha, provided they are placed on an Atlas (by specifying the packing tag) and the build is for Android. You can opt in for this by setting the Compress using ETC1 checkbox for the Texture. Under the hood Unity splits the resulting atlas into two Textures, each without alpha and then combine them in the final parts of the render-pipeline.

If you absolutely want to store an alpha channel in a Texture, RGBA16 bit is the compression format supported by all hardware vendors.

• 2017–09–18 Page amended with editorial review

• Updated feature in Unity 2017.1

• Crunch compression format updated in Unity 2017.3