I know how you do it on MAX but I want all the benefits of unity terrain editor; wavy foliage, texture painting, terrain sculpting in editor. What I want to know is how can you make something with the complexity of roads and streets in games like GTA in Unity? I mean, if you’re editing miles of roads and you want it to look like this:
What process would you use? Model terrain with roads in max then export the roads to .FBX, export the terrain to height-map, load the height-map onto unity terrain then import the roads? What do you do?
You’re going to have to use 2D fillers and billboards if you’re going to have miles and miles of roads with vegetation of that density. Easy Roads 3D, MegaShapes, and some other similar assets in the asset store can help you but you have to restrain from butting to many polygons in the game. Unity 5 will improve the situation but unless you know you are publishing a 4.7GB DVD to a console you need to simplify. fatBox Software if you search these forums likes doing racing games too and has some tutorials. Unity also has a Car tutorial (look under anouncements) and the new beta ‘Standard Assets’ has some new examples with new controls and such.
You could approach this several different ways, but assets that generate them in engine like goat pointed out is your best choice.
I think cryengine had something similar too where you would place your curves in editor and it would generate roads based on that curve in realtime. I wouldn’t be surprised if open-ended games such as GTA, Test drive etc relied on similar but more advanced technique with support for complex interesections etc etc.
Whether Unity is designed to handle such large environments even with most careful optimizations is another issue though…
