A few times I've pointed out the need to determine a mapping strategy according to your end goal, be it a self-contained, single game texture or a series of texture sheets for high-resolution model painting. In this case, we've wound up with the outer and inner parts on two different textures, and the additional meshes mapped with the interior. The ship hull has been split into two pieces, so we have to assign a unique material to each, to preserve their mapping, before the halves are welded back together.
Then we need to prepare the asset for painting, and there are a few different options for this. One option is to render a texture template from the Edit UVWs window, which is good if you plan to work in Photoshop (for a model that suits this, like a low poly prop). Another option is to paint directly on the surface. In this topic we'll look at how to prep for Mudbox painting, and at how we can view the UVs while painting in Viewport Canvas as well.
To map the supplemental...