Creation of roads and driveways that follow mesh surface

[Josh Verran]

Having some difficulty with creating roads and driveways.
If we have a mesh (usually created using XYZ import from survey data) there are numerous nodes.
We copy the mesh, change attributes to resemble a road (surfaces, building material etc).
Then we cut away the areas of that duplicated mesh to form the road shape (hopefully that makes sense, happy to clarify with images or video if needed).
This more often than not, results in an invisible mesh with the error message advising issue with polygon.
This seems to be the result of nodes being too close together after a cut etc.
As you can imagine it's near impossible to try and resolve these nodes, due to the sheer number.

Any suggestions on a better workflow, method etc?

In general, finding the site tools to be very restrictive.

[Hmooslechner]

what about an extra thing for it? Something like this?

https://www.dropbox.com/s/ui7k15dyus1dyjg/Bezierpolygontube4.pln?dl=0



german but deeper in the topic:

[Jp1138]

We usually use slabs for roads. You import the terrain as you said, then model the road in plan view as a slab with road atributes (materials, etc). The slab must intersect the terrain in all points. Then you can perform a SEO operation getting the intersection between slab and terrain, and then another one that substracts the road from the terrain. This way the road and the terrrain remain connected: if you modify the terrain the road follows along. This works well for general views, etc. If you need a detailed road it becomes harder, as you must create the road, sidewalks, etc, using the terrain mesh, but in any case from your post it seems that that is what you are doing. Hope this makes sense.

[Josh Verran]

Thanks very much for the suggestions guys.
I will try those methods.