RGBA_TexturePacker

Important Notes

• Do not use PNG files with transparency, as unexpected results may occur.
• Use grayscale images for channel slots other than the RGB slots.
• The 3D view result is for reference purposes only and may not perfectly match how the texture appears in the game engine.
• Packing textures may take a few seconds depending on the input files.
• Currently, the 3D view does not include the Detail Mask. To verify it, check the results in Unity.

Texture Packing Tool

This tool is designed to combine multiple texture maps into a single texture for use in game engines such as Unity, Unreal Engine, and Godot. It supports Metallic, Roughness, Ambient Occlusion (AO), and Detail Mask maps.

Channel Configurations

For Unity's URP standard LitShader materials and HDRP mask maps, textures are extracted from the following channels:

• R Channel: Metallic Map
• G Channel: AO Map
• B Channel: Detail Mask
• A Channel: Smoothness Map

In Unity, the Smoothness Map is automatically generated by inverting the Roughness Map, which is a feature unique to this engine.

While I do not use Unreal Engine, the included Unreal preset should work well for most users. The default configuration is:

• R Channel: AO
• G Channel: Roughness
• B Channel: Metallic

The Godot engine can also use the same configuration as Unreal Engine.

Key Features

Even if the packed texture appears transparent, all channel data remains intact. Although Photoshop may not display channel information for PNG files, game engines like Unity can accurately separate and render the R, G, B, and A channels.

Sample for transparency test

Alpha = 1 (A Channel: White Texture)

When the alpha value of the image is set to 1, all channels blend seamlessly.

Alpha = 0 (A Channel: Black Texture)

If the alpha value is inverted to 0, the result appears transparent.

but, even if the image appears transparent, this does not mean the channel data is lost.

 If you import the compressed image into Unity, you will see that the images in each channel are well preserved. Note that this cannot be verified in Photoshop.

Unity-Specific Settings

"Alpha is Transparency" Setting

The "Alpha is Transparency" setting must never be enabled. If this setting is turned on:

...all channels will appear transparent as shown.