Texture Compression

Cocos Creator can set the compression method required for textures directly in the editor, and then automatically compress the textures when the project is released. Multiple image formats can be exported at the same time, and the engine will automatically download the appropriate format according to different devices.

Configure compressed texture

Cocos Creator supports importing images in multiple formats (see the table below for details), but in an actual running game, we do not recommend using the original images as assets to load. For example, on a mobile platform, only 80% or less of the original image quality may be required, or a .png without the transparent channel can be converted into a .jpg, which can reduce the storage space required.

Image format	Android	iOS	Mini Game	Web
PNG	Supported	Supported	Supported	Supported
JPG	Supported	Supported	Supported	Supported
WEBP	Native Supported for Android 4.0+ Other versions can use this library	can use this library	Supported	Partially Supported
PVR	Not Supported	Supported	Supported iOS	Supported iOS
ETC1	Supported	Not Supported	Supported Android	Supported Android
ETC2	Partially Supported	Not Supported	Not Supported	Supported Android
ASTC	Partially Supported	Partially Supported	Not Supported (WeChat Mini Game v8.0.3 or above for iOS are supported.)	Partially Supported

By default, Cocos Creator outputs the original image during build. If you need to compress an image during the build process, you can select this image in the Assets panel and then manage it in the Inspector to edit the compress texture format of the image.

The presetId option defaults to the compression texture preset provided by Creator, and the image compression format shown here is read-only. To add more presets or edit them, click the Edit Presets button next to the presetId to open the Project Settings -> Texture Compression panel for setting.

Note: after configuring texture compression, only images of the corresponding format will be generated at build time, if some image formats are not supported on some devices, it will cause abnormal display. To avoid this problem, when adding texture compression presets, please select additional general image formats (e.g. PNG, JPG) as default images.

The compress-texture options on the image asset will be stored in the asset's meta file. PresetId is the ID of the selected compressed texture preset.

Detailed compression textures

When Cocos Creator 3.0 builds the image, it will find whether the current image has been already configured to use compressed textures. If not, it will output the original image.

If the configuration of the compressed texture is founded, the image will be compressed according to the configuration.The compress texture configuration in the project settings is divided into different platforms, and the support of in the actual platform is also difference. builder will make certain elimination and priority selection of the configured texture format according to the actual build platformand the current image texture transparency channel. You can refer to the following example to understand this rule.

Multiple texture formats can be specified on one platform, and each texture format is compressed to generate an image of the specified format when it is constructed.

These generated images will not all be loaded into the engine during runtime, the engine will choose to load the appropriate image according to the configuration in macro.SUPPORT_TEXTURE_FORMATS. macro.SUPPORT_TEXTURE_FORMATS enumerates all the image formats supported by the current platform. When the engine loads the images, it will find, from the generated images in this list, the format with the highest priority (that is, the order is higher) to load.

The user can customize the supported image assets for a platform and the priority of the loading order, by modifying macro.SUPPORT_TEXTURE_FORMATS.

Example

Example 1: As the compress presets of the MiniGame platform shown in the figure, if the build target is Huawei Quick Game That only runs on Android devices, Builder will not package the PVR texture format. For more details about the support of platforms, please refer to [Details of compressed texture support for platforms](##Details of compressed texture support for platforms)

Example 2: In the example picture above, both ETC1 and PVR types are configured with RGB and RGBA two types of texture formats. In this case, Builder will be according to whether the current picture has a transparent channel to choose one of the same types of formats. The image asset in the example is with a transparent channel, then Builder will only pack a compressed texture format with REGA type. Of course, if there is only RGB picture format in the configuration, even if the current picture is with a transparent channel, it will be packaged normally.

Details of compressed texture support for platforms

Except for the JPG and PNG supported by all platforms, the details of other formats are as follows:

Platform	TextureCompressTypes
Web Desktop	ASTC / ETC2 / ETC1 / PVR / WEBP
Web Mobile	ASTC / ETC2 / ETC1 / PVR / WEBP
WeChat Mini Game	ASTC / ETC1 / PVR
AliPay Mini Game	ETC1 / PVR
Baidu Mini Game	ETC1 / PVR
OPPO Mini Game	ETC1
vivo Mini Game	ETC1
Huawei Quick Game	ETC1
Cocos Play	ETC1
Xiaomi Quick Game	ETC1
iOS	ASTC / PVR / WEBP / ETC1 / ETC2
Android / Huawei AGC	ASTC / ETC2 / ETC1 / WEBP

Custom build texture compression processing

Texture compression currently takes effect after the build, and the editor comes with a set of processing tools. To customize the compression tool, please refer to the Extending Build Process -- Custom Texture Compression documentation.