Cnc model creating site model

Rhino
1

Hi guys,

I’m working on a CNC model and need to integrate roads into the single polysurface (topo). What’s the easiest way to project and extrude them on the topo?

Thanks for your time!
Sincerely
Deniz

Screenshot 2025-02-28 150734
Screenshot 2025-02-28 1507341920×1200 176 KB

CNC Model.3dm (1.8 MB)

2

one way:

  1. extrude road curves not as solids so they completely intersect the topo surface (ie extrude -Z by 1000ft)
  2. split the topo surface with the road extrusions, delete or group/hide the road extrusions
  3. extrude the split road surfaces “down” (ie -Z direction) by ~6-8" depending on the curb height in real life
  4. extract only the the top surface of the road extrusions in step 3 and delete them
  5. then join all the patches together

this should give you a model with the terrain cut into blocks by roads.

also,i see something that looks like a highway overpass. it would be easiest to build the bridge, abutments, and piers as separate pieces that are attached to the topography afterwards. the retaining walls can sometimes be milled out of the same stock as the topography if you have a tapered bit or a 1/16" ball-end bit. alternatively build the retaining walls as separate pieces and attach them to the topography.

make sure the all the curves that you extrude are closed curves

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