3D vector tool path

If I have a terrain map with topography information (either Fusion or Carbide Create grayscale height map) is there a way to trace a line on that map for a road or trail that follows the terrain? I know I can create the shape by rastering back and forth across the whole terrain, with the ball end mill dipping in and out of the trail as it comes across it, but the line would look better and cut much more efficiently if it could just trace trail itself from start to finish.

Any ideas? Updating the grayscale height map will only give me the raster solution. Drawing a separate vector will lose the Z-axis information. How can we draw a vector in 3D space that the tip of the end mill will follow?

See this image for the concept in 3D printing: https://www.thingiverse.com/thing:201405


I wanted to do the same thing. I used a subtraction layer in the 3D modeling. I make a graphic with just the trail lines, and then used that image to subtract/lower the terrain a set amount.


hmm I’ve wanted to do this with a laser at some point (but I dont have a laser yet for my shapeoko)

The way I would probably do this is using TouchTerain to get a nice STL for the terrain, openstreetmap to get an SVG, and I’d enhance https://fenrus75.github.io/FenrusCNCtools/stl2nc/stl2nc.html to also take an svg for a V bit (I’d do the roads with a sharp edge v bit) where the Z comes from the STL.

But… easy it is not. I would also worry about misalignment between openstreet map and google data (that touch terrain uses)


hmm option 2 is to do all of this in blender-GIS I suppose, that way you get openstreetmap for both the terrain AND the road.

(if you haven’t used blender-GIS yet… there’s some cool youtube videos/tutorials for it, and once you get the design in blender that you want, export to an STL + stl2nc to get gcode and it cuts at high def… some pictures in MDF at Cityscape of Portland OR)


Hmm I should build a tool that takes an stl and gcode and overlays the gcode on top of that stl,. Then this would work naturally. Does not sound insane hard to be honest so if I get some spare time…

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I’ll add that you might find interesting ideas in the definitive thread from @ClayJar for all things terrain:

He uses a laser to draw the trails, but I guess adapting it to use a small tapered endmill would be doable.


That write-up is fantastic! I’ve skimmed it but not gone through in detail, but it’s exactly the right idea. Thanks!