18. Custom channels

For what channels do, see chapter 6. Here is how to add your own.

In OP Settings ▸ Channel visibility & custom channels ▸ Add custom channel, type a Key, a Label, then press +. For example, key Wear, label Wear Mask. The key is the internal name (letters, numbers and underscores), the label is what you see in the panel.

The new channel becomes visible straight away. Target it from a sublayer's ribbon, paint or generate its content, then choose it as an export source. To use it in your own shader, expose a matching input (chapter 14).

A few limits

• Up to eleven custom channels beside the built-ins. Use a unique key and label, do not add Opacity, Coat etc. again (show the built-in one).
• Custom channels do not connect to the standard BSDF automatically. They are available for export and custom shaders.
• Their new images use Mask / Paint Canvas Format defaults, they have no separate row in Image Bus Channel Defaults.
• The channel definitions live inside the .blend, so they travel with the project.

Hiding and removing. Hide a channel in Channel visibility when you do not need it. There is no remove button yet. To remove it fully, edit the OP_Painter_Channels text datablock in Blender's Text Editor, remove its entry, save and reload (it stores key/label pairs as JSON).

Missing after opening a file? Re-add the same key, or restart with that file open. Re-adding reads the file's existing definitions too.