How to connect two modules perfectly?

I'm trying to build a long wall and i try to place the modules next to each other perfectly but it never comes out perfectly and always at play, I see the connection of the modules to each other.

Is it possible to connect them to each other automatically?

you can press 'b' twice in the editor to turn on grid mode but it's still not perfect

you're right it's not perfect but it's much better than before.

I have tried pressing b twice and also don't find it perfect, the best way I find is to get in really close and place the objects in the editor by eye.

If your wall "modules" are 100 units wide and textured seamlessly, the grid snap will do a pretty good job putting them together. In Blender, I place the "exterior" side (front) 50 units out from 0 on the y axis, (which is the z axis in reloaded, the way it should be!). Then, when I rotate a wall 90 degrees, it will snap accordingly. Hope I explained that well enough! Example of a finished structure:









EDIT: I'm still playing with the contrast/brightness/ambience settings on this map!



This whole structure was built with essentially one wall segment, with a little Boolean subtraction for doors and windows. And, obviously, one texture! LOL