Alright, so I have a decent amount of experience 3d modeling. Not much with unreal and modular assets though. .
I’d like to think I’m decent at uv mapping. . Especially the tedious manual stitching ****. lol. However, I can’t figure out how to uv map a modular asset kit for the life of me. . I want my textures to seam perfectly. I already know how to uv map the lightmap without issues. What’s getting me is having perfect tiling happen from one modular piece to the next. Unfortunately my walls aren’t just straight pieces. they’re shingled like house sidings, and some of the modular objects are different in length. IE: One piece might be 140cm wide, while the next might be 280. I can cut some of them in half so that every piece is 310cm tall and 140cm wide. However I’d rather not if I didn’t have to. It’s a lot of meshes to go and edit, and it’s going to require left and right sides. Literally doubling the amount of assets in some cases.
So. . . if I have a hypothetical box, 310cm tall, and 140cm wide. . . How can I UV map them so that the edges of the walls seam up nice with the others? In any order I put them in?
Think of the walls like A, B, and C.
I need them to tile perfectly whether I have ABC, BAC, CBA, etc, etc.
If the walls were square, IE, 310cm X 310cm, this wouldn’t b a problem AT ALL! I could just use the entire 0,1 space in one uv channel and problem solved. However, I won’t be able to do it this way, because the texture will stretch, and my walls are different sizes, plus most of the exterior walls have windows built into them, and top and bottom trims are also on the walls.
My only thought of doing this as a work around is to stretch the UVs across the entire 0,1 space, and use a tex coord to scale it back. . .
…Discuss please! 
Also, if it would be easier, I would be more then willing to upload like 2-3 of the exterior wall assets. Perhaps someone can uvmap one so I can see how modular uvs are done?