Hi,
I am looking for some advice on the correct workflow for a complex object I am creating.
I'm working with 3DS max and substance painter 2.
I am creating a model of a spaceship, which requires both a visible exterior and interior (It's for a game).
This has presented a challenge. Unwrapping and texturing the entire ship as a single object is not really possible due to the complexity, so I decided to model the ship in several pieces, with each interior room being once piece.
This worked well, but I am now having a problem aligning the textures between these different objects.
This image should show what I mean:

Here, the upper texture is one object, and there are several rooms below this, which are individual objects, once of which has a texture on it.
What I want to do is match up the texture from the upper object to the lower object, without leaving a seam, while still being able to unwrap the interior as a separate object. I would also like to be able to eliminate seams around the windows, etc.
My knowledge of unwrapping and texturing is not extensive, so this may be simpler than I am making it, but I would appreciate any advice than I could get.