I can understand the concept of creating a network of basic roads using splines but imagine a large area of concrete with lots of complex curves, shapes and transitions to model like an airfield. The area of concrete could extend to over a mile. What would be the best way to model this please? I’m looking for proper mesh modelling here - not an applied texture. Is there any problem using a vast mesh or would you break it down into smaller sections? I would need to be able to view the paths and runways stretching out into the far distance so a LOD based system wouldn’t work so well. I’d also need vehicles to be able to operate realistically on the surface, following any contours I build into the mesh. Am I asking the impossible!? Thanks!
I think you could probably approach an airfield the same way you would approach roads and intersections, just with different markings/appearance. I would recommend checking out Epic’s presentation on the roads for the matrix. This is more of an advanced setup since it leverages Houdini, but I think you get the idea The Matrix Awakens: Generating a World | Tech Talk | State of Unreal 2022 - YouTube
I would also recommend tutorials for creating spline meshes, like fences. You can make a road a spline mesh as well!
When I did this many years ago (DX9 era, in a custom engine,) we ended up with an alpha-based fringe map. So, we built five different concrete textures, and then used a sixth RGBA texture to “paste” those concrete textures on top. The trick was that the blending function was not plain blend, but used a much steeper curve, and then added in an alpha channel from the blended-to texture. This way, “hard” edges, such as seen where parts of asphalt have been poured on top of older asphalt, could be modeled. (Also great for grass fringes and such.)
The blend function was something like outcolor = lerp(basecolor, overlaycolor, clamp(blendValue*4-1.5+overlaycolor.alpha))
These days, you might easily make something like that with the unreal terrain sculpting support. You can also use decals for all the painted markings and tire marks. The main goal is to get a variety of concrete textures on there, without getting any obvious tiling, hence the multiple different textures to vary at the macro scale.