How to pattern holes in an STL surface

I have an STL file of part of an airway, it’s a fairly complex biological shape but I’ve reduced the triangle count significantly to keep it manageable. I would like to be able to apply a pattern of circular holes to its surface (like a simple polka dot pattern of 2mm holes), but don’t know enough about Rhino to know if that is even possible. I know it is somewhat limited when it comes to modifying STL files. I can manually add a mesh cylinder, manually position it, and then do a boolean subtract operation to cut holes into this thing one at a time, but I am in need of a more automated way of doing this. Does anyone have any ideas as to how I can go about doing that? Is there any other software that might be better?

I’ve attached the STL file of the part, as well as an STL of just the outer surface in case it’s better to work with just that. Thanks in advance, much appreciated!

Outer surface only.stl (187.7 KB)
Full model.stl (305.3 KB)

Hello - is this for visualization or do you need the 3d holes?


Would need actual 3D holes.


OK I guess it will be a workaround, at best, either way. Something like

Make curves approximating the centerlines, then ArrayCrv a cylinder along the curve such that the results poke fully through the tube, then use these as cutters…

@Anon_Anon, Taking this a little further, make your centerlines, piple the curves withPipe>Cap=None roughly the same diameter as the mesh tubes, and then Rebuild the resulting surfaces to a fairly dense point count - on the order of say 50 along by 30 around, degree 3 for U and V both. This will ensure that the UV is evenly distributed - then you can ArraySrf a cylinder on that surface.


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Ahh that command might help. I’ll have to tinker around with it, thanks!

Oh wow, that seems even better. I’ll try that out. Thanks!