STL to Toolpath journey of death

I’m working on a project that will be taking scan data (as STLs) and outputting it as CNC milled foam. The machine I have uses grasshopper to generate the tool paths so I would like to use Rhino to edit the STLs created from the scan data before using grasshopper to generate the g-code.

How am I best to use the STL files within Rhino, should I convert them into another file type before i edit them? Solid or Mesh?I will be wanting to split models up and add features to them before preparing them for milling.

Any tips would be very gratefully received, please let me know if you need more to go on!


I don’t think you can convert them to a solid. A stl is a mesh as far as I know?

Rhino is probably not the very first choice for editing mesh objects directly in the way you describe, especially dense ones, as scans tend to be - There are mesh editing tools in Rhino but the ones that involve mesh intersections, mesh trimming and splitting are not among Rhino’s most robust features, especially if the mesh is at all imperfect - non-manifold edges, self-intersections and so on make life harder. Not that you cannot do it, necessarily, but it might be fairly labor intensive.

My guess is that, as a general procedure, you’d build the features you want in the normal Rhino way as surfaces etc, then generate mesh versions of these and trim them into your mesh objects.


Thanks guys, looks like i’ll have my work cut out in Rhino, perhaps my best option is to prepare the scans in another programme before I import for grasshopper attention?

I use geomagics for scan processing but if you could suggest a more mesh friendly modelling programme i’ll have a look