UV shells distribution and texture painting

Vyalam

Hey. I've trying to get this solved but the result is always the same in low poly, specially

I'm trying to create this mesh; a platform connected with bridges and I created 3 UV snapshots for all this. However, I'm not sure about the distribution of UV shells, their size or anything else to fix. Here I'm leaving some images of my work so far. I didn't continue since the quality of the textures work didn't convince me. I tried painting directly in the UV snapshot (1024 of resolution, btw) but everything looks bad when I work it so I have to work every texture in a separated 1024 image so I take it back and scale it down, losing its quality, I know.

ZacD

If you are tiling textures, like the walls, you should have the UV's overlapping so they share the same texture space. Anything that can share textures should use texture. 

Vyalam

ZacD said:

If you are tiling textures, like the walls, you should have the UV's overlapping so they share the same texture space. Anything that can share textures should use texture. 

Yes, just as I thought. Now... suppose I wanted to add soil and green dirtiness around specific zones of the walls, for instance, to tell some zones apart... Would I need UV sets or any other way to add them? I'll try to show my rearrangments of UV snapshots to see if it's heading to a good way.

ZacD

You could use vertex painting, thirding (tiling the middle of the texture, but having a unique top/bottom. Typically it's more like the 1/6 is unique the middle 4/6 tiles with itself, the bottom 1/6 is unique.), or multiple textures. 

musashidan

Or you could use custom opacity masked decals. These are usually projection mapped in-engine.

Vyalam

ZacD said:

You could use vertex painting, thirding (tiling the middle of the texture, but having a unique top/bottom. Typically it's more like the 1/6 is unique the middle 4/6 tiles with itself, the bottom 1/6 is unique.), or multiple textures. 

You'll have to forgive me for the ignorance , but... This is the first time I heard about vertex painting... what is it exactly? And I'd like to know about how can I improve my texturing quality. For instance, in the image I'm showing ( https://cdn3.artstation.com/p/assets/images/images/002/019/907/large/clayton-chod-observatory-final-contact.jpg?1456082764 ) the artist assembled a lot of UV shells inside of one single UV image of a 1024 resolution. When I paint, just like that, obviously looks low quality and pixelated, which forces me to work in another file to put it back there, but scaling it down. Is there any method I'm missing for better quality? like working in 4096 and turn it to 1024? or something else? and I've heard that there's a way to "vectorize these pixels" in Photoshop or something. Sorry for the huge post and request about this basic matter.