Modular Asset UVs V1 - Alignig

If I was going to model the entire town with tileable textures, I had to ensure that my UVs were laid out that would:

A) Make sure the applied textures looked natural without visible seams
B) The UVs were prepared in a way which would mean no adjustments or tweaks would need to be made after applying the tileable material.
C) The resolution would have to match on all assets. (with some potential acceptations such props only visible from a long distance like mountains or plants etc)

The idea is to invest time in setting up the UVs to save time of texturing and making several adjustments when it comes to the texturing stage.

First, I aligned the top and bottom parts of the buildings, snapping them together vertex to vertex. Both building blocks (top and bottom) have the same material, although they will be two separate models. 

I found it hard to stare at the black and white chequers and was unable to determine whether the UVs were matching up perfectly. I googled "Chequered UV texture" and found the one in the image below (Duber's blog, 2008)

I could now see that the front and the sides of the buildings match up perfectly, as if they were one single mesh. 

I did not worry about matching up the interior UVs as the player wouldn't ever get to see these close enough. 

My thought process was "if I am going to have separate Light Map Uvs anyway, why can't my Texture UVs overlap?" So I ran a test. 

With the UVs aligned, and kept in groups, I stacked the shells and made sure everything looked ok in the viewport. 

I Imported the the both models into Unreal and checked that the UVs on the on set two, generated by the engine weren't overlapping. 

I applied a test texture, and backed the lights in engine. 

The result was no issues with overlapping textures and no backed or real time lighting issue with this method. So I will use this going forward. 

One thing to note. The sides of the buildings won't ever match up, as the are curved. I will model some Pipes and Trims to cover these. 

Reference:
Duber's Blog, 2008. Custom UV and Tracking maps for VFX Professionals. Available at http://blog.duber.cz/misc/custom-uv-and-tracking-maps-for-vfx-professionals [Accessed on: 08/11/2017)