Merge UV Layers

In Genesis 8, the eyelashes are also implemented as a separate mesh. We can not use Merge Anatomy on these, because the eyelashes are not grafted items, but it is easy to join them to the main body using Blender's standard tools. With the eyelashes selected and the body mesh active, join the meshes without deleting any vertices (ctrl-J shortcut with Blender 2.79 keymap).

However, there is a problem. When two meshes are joined, the combined mesh has several separate UV sets, one for each original mesh. The UV coordinates for each eyelash vertex is (0,0) in the UV set that comes from the body, and the interesting UV coordinate only exist in the second UV set. So we need to merge the UV sets as well.We see that there are several UV Maps.

We want to merge the Base Female UV map from the body and Basic Female from the eyelashes; the other two UV maps come from the merged geografts and should not be merged. Make sure that Base Female is the render UV map (the camera icon is highlighted) and press the Merge UV Layers button.

In the pop-up dialog we choose which UV layer to merge (the Basic Female layer which comes from the eyelashes). The active UV layer (Base Female) is also shown.

Afterwards the first and fourth UV layers have been merged.

The UVs for the eye-lashes are merged with the other UVs. Any named UV set node in the material node trees is also updated to the merged UV layer.