Channel Packing

Channel packing is a way to reduce resources consumption by assets by combining multiple maps in multiple channels of a single image. Channel packing is often used to optimize performance of assets in game engines.

Channel packing can be performed with:

  • image editing software

  • the Blender compositor

The channel packing operator in RGBA Bake works on images and mesh color attributes.

_images/channel_packing_image.png

Channel packing a Roughness map to the red channel in a RMA image containing Roughness, Metallic and Ambient Occlusion maps

This operator allows to stay in Blender to channel pack without using the Blender compositor.

It can copy channels with different methods:

  • Copy aligned channels

    Each channel in the source are copied to the target

  • Copy single value

    A single source channel can be copied to the target

  • Copy averaged values

    Multiple source channels can be averaged and copied to the target

Usage:

  • Execute the operator Channel pack RGBA

  • Select the Channel Pack Mode

  • Configure the images or mesh color attributes

  • Configure the channels

  • Launch the operator Channel pack RGBA

Pack Unsaved Changes

This option is relevant if Channel Pack Mode is Image. Pack any unsaved changes to the image otherwise abort the operator.

Align Each Channel

Each source channel will only change the associated target channel.

Example: The source red channel will only change the target red channel.

Note

In most cases, the source image will be a grayscale image. It means that the red, green or blue channel can be used as the source.