Recent maps like Italy and (revamped) ECA use a combination of terrain materials and decals for ground-level roads, while (revamped) Hirochi Raceway use meshes exclusively. Is there a decided preference among the official dev team? If not, do they have any thoughts on them compared with each other?
Race track uses meshes as it's not bound to terrain limitation (ie. can be higher resolution, hence smoother and more accurate) Terrain is better for larger scale.
