Michael
Michael
See also [CGAL FAQ](https://www.cgal.org/FAQ.html#inexact_NT).
If you're operating in the sub-ten size with detailed curves, that is a problem area. So work even in the x100 space, then scale(0.01), will *often* work in OpenSCAD without...
Netfabb PC, so I assume online, does not automatically check for self-intersections. You do it manually: Scans are often bad. _____ From: Claghorn ***@***.*** Sent: Sun, 11 Apr 2021 23:53...
hmm, didn't like the image in email... 
> So am I just coming up against an inherent limitation in OpenSCAD? Or CGAL? Or is there a better way to model this? Or is there another program that...
Oops, that rotate had side effects. Try ``` for(i=[0,len(angles)-1]) // 90 works rotate([0, angles[i], 0]) rotate([0,0,i*3.14159]) cylinder(d=thx, h=long, center=true); ```  That too 30 minutes to render, so your lattice...
This last example also crashed 2015.03-2. Exception Code: 40000015 Some [digging](https://stackoverflow.com/questions/99552/where-do-pure-virtual-function-call-crashes-come-from) shows. > They can result if you try to make a virtual function call from a constructor or destructor....
Netfabb doesn't show self intersecting faces, which your poly has:  (I deselected the unify faces option on loading it) Below is with unify faces selected, still...
Not intersecting itself, one face intersecting another, rather than sharing edges. See the images [here](http://blender.stackexchange.com/questions/9175/how-can-i-join-the-geometry-of-intersecting-faces-planes-and-then-remove-parts). @kintel in my travels I came across [this](http://doc.cgal.org/latest/Polygon_mesh_processing/#title18) > Self intersections can be detected from...
@indazoo also see [this](http://forum.openscad.org/strange-polygon-behaviour-in-small-scale-td17390.html), as your poly has small numbers it could be the issue.