[OpenSCAD] Error importing STL.

Rogier Wolff R.E.Wolff at BitWizard.nl
Mon Oct 10 06:06:54 EDT 2016


I have an STL file that I want to print. The first attempt went bad
because the object didn't stick to the brim I ordered.

This occasionally happens, and I then add a cylinder with say 6 radius
and 0.6 height to the corners to make it stick better. The extra
material is easy to clip away after printing.

So I load this model 

which is a "distributed" version of: 

into openscad with 
  import("Top_vert_conic_extruder_sm_endstop_v3.STL", convexity=5);

This views just fine (F5 - Preview), and renders too (F6-render). 

Then I add one of my cylinders and it suddenly gets errors....  The
errors do not give any useful information as to what goes wrong:

When I hit "F6 - render", I get: 

Compiling design (CSG Tree generation)...
Rendering Polygon Mesh using CGAL...
ERROR: CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation! Expr: pe_prev->is_border() || !internal::Plane_constructor::get_plane(pe_prev->facet(),pe_prev->facet()->plane()).is_degenerate() File: /usr/include/CGAL/Nef_3/polyhedron_3_to_nef_3.h Line: 251 
Geometries in cache: 10
Geometry cache size in bytes: 1389248

in the log window, and many repetitions of: 

Error !!!!!!!!!!!!!!!!!!!!!!!

in the stdout of openscad. 

For "getting my print job done", it seems the github version is
"Better" in some way that it does not cause havoc with openscad.

I don't need help finding a workaround for this specific file: the one
from github works. 

A better error message in openscad could help people less seasoned as
me in finding a workaround. I still need to print a few objects from
that set, so I would like to know WHAT is wrong, and how to fix/avoid

screenshots at: http://prive.bitwizard.nl/f5.png
and http://prive.bitwizard.nl/f6.png


** R.E.Wolff at BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 **
**    Delftechpark 26 2628 XH  Delft, The Netherlands. KVK: 27239233    **
*-- BitWizard writes Linux device drivers for any device you may have! --*
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