In my game I’m using a environment modular pack. However I cannot seem to get these parts to blend seamlessly. It is always visible (a thin line) where it is divided. How can I make them blend seamlessly?
Well, the issue with your road pieces is that each piece has side faces. Since they have a different color than the top face you get z-fighting at the edge. Such modular parts shouldn’t have any side faces which wouldn’t be visible anyways.